Neonicotinoid insecticide use has been suggested as a cause of honey bee colony decline; however, detection rates and concentrations of neonicotinoid insecticide residues in field-collected honey bees have been low. We collected honey bee and beebread samples from apiaries in agricultural, developed, and undeveloped areas during 2 years in Virginia to assess whether landscape type or county pesticide use was predictive of honey bee colony exposure to neonicotinoid insecticides. Trace concentrations of the neonicotinoid imidacloprid were detected in honey bees (3 of 84 samples, 2.02–3.97 ng/g), whereas higher concentrations were detected in beebread (5 of 84 samples, 4.68–11.5 ng/g) and pollen (three of five pollen trap samples, 7.86–12.6 ng/g). Imidacloprid was only detected in samples collected during July and August and was not detected in honey bees from hives where neonicotinoids were detected in pollen or beebread. The number of hives sampled at a site, county pesticide use, and landscape characteristics were not predictive of neonicotinoid detections in honey bees or beebread (all P > 0.05). Field surveys may underestimate honey bee exposure to field-realistic levels of pesticides or the risk of exposure in different landscapes because of low detection rates. Undetectably low levels of exposure or high levels of exposure that go undetected raise questions with regard to potential threats to honey bees and other pollinators.

Unlike many other rosaceous fruit crops, commercial raspberry cultivars are largely self-fertile and mostly selfpollinate autogamously. However, their floral morphology does not allow for complete autopollination, which often yields unmarketable small or crumbly fruits. Insect visitation is therefore essential to maximize raspberry production. Honey bees are typically used to pollinate commercial raspberries, but escalating prices for hive rentals coupled with increasing acreage encourages evaluation of other manageable pollinators. Four other manageable bee taxa—various Bombus spp., Osmia lignaria Say, Osmia aglaia Sandhouse, and Osmia bruneri Cockerell—are all promising raspberry pollinators. Because honey bees remain the least expensive option on a per forager basis, adoption of an alternative pollinator should entail some other advantage, such as superior pollination efficacy. In this study, we compared honey bees with these other bee species for their pollination efficacies at red raspberries, measured as the number of drupelets resulting from a single visit to a virgin flower. Each species' single-visit pollination efficacy was also compared with drupelet set from both unvisited and hand-pollinated flowers, and their pollination effectiveness scores were calculated. All five bee species were equally effective raspberry pollinators; therefore, honey bees remain the most cost effective option for open field pollination of raspberry. Mason bees and bumble bees may have greater utility during cool weather or for protected cultivation systems, contexts unfavorable to honey bee foraging.

Despite receiving much attention, the ectoparasitic mite Varroa destructor (Anderson and Trueman) and the pathogens it vectors remain critical threats to the health of the honey bee Apis mellifera (Linnaeus) (Hymenoptera: Apidae). One promising intervention approach is the breeding of hygienic honey bees, which have an improved ability to detect and remove unhealthy brood from the colony, and are thus more resistant to Varroa. While much hygienic behavior-related research has focused on enhanced adult honey bee olfaction, less attention has been paid to the olfactory signals that originate inside the brood cell, triggering hygienic removal. Here, we hypothesized that selection for hygienic behavior in honey bees has influenced brood signaling, predicting that: 1) in a common social environment, removal rates differ among brood with different selective breeding histories, and 2) the removal rates of brood positively correlate to the hygiene level of the brood's colony of origin.To test these predictions, we cross-fostered brood subjected to control, wound, or Varroa treatment in unselected (UNS), Minnesota Hygienic (HYG), and Varroa-Sensitive Hygienic (VSH) colonies, and monitored individual brood cells for hygienic removal. Results confirmed both predictions, as brood from hygienic colonies was more likely to be removed than brood from UNS colonies, regardless of where the brood was fostered. These findings suggest that hygiene-related brood signals complement previously identified characteristics of hygienic adults, constituting an important mechanism of social immunity in honey bees. Thus, selective breeding for honey bee hygienic behavior may be improved through the utilization of field assays containing compounds related to larval signaling.

Grapevine red blotch virus (GRBV) currently poses a serious threat to the wine industry. The three-cornered alfalfa hopper (3CAH), Spissistilus festinus (Say) (Hemiptera: Membracidae), was recently shown in a greenhouse study to be a vector of GRBV in grapes. Feeding and reproductive status of 10 weed and 10 cover crop species commonly found in grape vineyards were evaluated in no-choice tests. Species confirmed as reproductive hosts were subsequently evaluated in choice tests to determine S. festinus oviposition preference. Spanish clover, dandelion, birdsfoot trefoil, common groundsel, field bindweed, magnus peas, bell beans, blando brome, purple vetch, black medick, subterranean clover, crimson clover, and woollypod vetch were all found to be reproductive hosts. The plant species that exhibited the greatest nymph emergence in each of the three groups tested for preference were all in the family Fabaceae. Knowledge of plant species present in vineyards that serve as alternative hosts for S. festinus can contribute to developing management strategies to mitigate virus spread.

Studies of the species composition, seasonal appearance, and abundance of Auchenorrhyncha in olive crops is of paramount importance to reduce the potential of Xylella fastidiosa to invade new areas. As similar investigations had not previously been conducted in Greece, extensive surveys were undertaken in olive orchards located in three of the most important regions for olive production in central Greece (Fthiotida), south-central Greece (Attica), and southern Greece (Chania). Surveys took place over a 13-mo period, using Malaise traps examined on a monthly basis. Results showed high levels of species richness in the olive orchards, and the Auchenorrhyncha diversity varied among the regions surveyed. Most of the species listed as potential vectors of X. fastidiosa in Europe were found in relatively low numbers. Furthermore, many insects of the Deltocephalinae subfamily were found, whose behavior as vectors should be further studied. The dominant and most frequent species found in the three regions were tested and found not to be associated with transmission of the bacterium. This study may serve as an alert, showing that the most commonly found species differ from those identified in similar studies in Italy, and thus other species should be examined as potential vectors. The results of the present study provide new insights into the seasonal abundance and dynamics of potential vectors of X. fastidosa in several regions of Greece, and also provide information that may prove valuable for the effective containment and eradication of this threat.

Asiatic huanglongbing (HLB), also known as citrus greening or yellow shoot disease, is a serious disease putatively caused by the bacterium ‘Candidatus Liberibacter asiaticus’ Jagoueix et al. (Rhizobiales: Rhizobiaceae) (CLas) transmitted by the Asian citrus psyllid (Diaphorina citri Kuwayama (Hemiptera: Liviidae)). Plant resistance to CLas holds promise as a strategy for reducing the economic impact of HLB; thus, citrus breeders are developing new varieties and cultivars and evaluating these for resistance/tolerance to CLas. A high-throughput inoculation program was established to expedite testing of germplasm. Colonies of Asian citrus psyllid maintained on CLas-infected plants are used for the inoculations. The primary inoculation step is to cage a healthy citrus seedling with new leaf growth for a 2-wk inoculation feeding period by 20 adult Asian citrus psyllids (no regard to sex or age) from these colonies. The adults are removed after the inoculation period, and the plants are then treated with a pesticide to eliminate any adults missed or infestation of immatures. The objective here was to evaluate inoculation rates under this procedure. Ten sets of 20 healthy citrus seedlings were subjected to the procedure, one set a month, and the percentage of seedlings successfully inoculated based on testing by quantitative polymerase chain reaction were determined 6 mo after each 2-wk inoculation period. The results indicated a 77% mean transmission rate (percent infected seedlings), with rates ranging from 40 to 100%. Transmission rates were positively correlated with the percentage of Asian citrus psyllid that tested positive for CLas but not correlated with titers of CLas in these psyllids. Possible reasons for variability in transmission rates are discussed.

Biological invasions of vectorborne diseases can be devastating. Bioclimatic modeling provides an opportunity to assess and predict areas at risk from complex multitrophic interactions of pathogens, highlighting areas in need of increased monitoring effort. Here, we model the distribution of an economically critical vectorborne plant pathogen ‘Candidatus Phytoplasma aurantifolia’, the etiological agent of Witches' Broom Disease of Lime. This disease is a significant limiting factor on acid lime production (Citrus aurantifolia, Swingle) in the Middle East and threatens its production globally. We found that temperature, humidity, and the vector populations significantly determine disease distribution. Following this, we used bioclimatic modeling to predict potential novel sites of infections. The model outputs identified potential novel sites of infection in the citrus producing regions of Brazil and China. We also used our model to explore sites in Oman where the pathogen may not be infectious, and suggest nurseries be established there. Recent major turbulence in the citrus agricultural economy has highlighted the importance of this work and the need for appropriate and targeted monitoring programs to safeguard lime production.

Soybean vein necrosis virus (SVNV), a new virus in the genus Orthotospovirus, has been found in all soybeangrowing regions in the United States and Ontario, Canada. Soybean thrips, Neohydatothrips variabilis (Beach) (Thysanoptera: Thripidae), tobacco thrips, Frankliniella fusca (Hinds) (Thysanoptera: Thripidae), and eastern flower thrips, Frankliniella tritici (Fitch) (Thysanoptera: Thripidae) are reported vectors of this virus, but there are no reports on their distribution in Alabama. A monitoring study was conducted in 2015 and 2016 to determine thrips species composition and abundance in Alabama soybean agroecosystems. Thrips were monitored weekly by collecting them on yellow sticky traps and soybean plant parts including foliage and reproductive structures. All three reported vectors of SVNV were identified in Alabama, with N. variabilis and F. tritici as the predominant species, while F. fusca was not consistently collected from soybean plants. Four additional thrips species were collected, of which Echinothrips americanus (Morgan) (Thysanoptera: Thripidae) was commonly found on soybean at all three locations. Results presented in this study provide new information about seasonal thrips species abundance in soybean agroecosystems in Alabama, and is an important first step to understanding thrips vector species of epidemiological importance in the Southern United States.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is the vector of the bacterium responsible for huanglongbing, a deadly plant disease affecting citrus worldwide. We investigated the effects of wind direction and speed on flight duration and direction of D. citri, as well as the effects of temperature and barometric pressure on sustained flight duration of D. citri. Experiments were performed with laboratory flight mills and wind tunnels. Flight activity of D. citri increased with increasing temperature. Of the few insects that flew at 18°C, most performed short duration flights (<60 s). When exposed to temperatures between 21 and 28°C, D. citri performed long duration flights (>60 s). In addition, the distance covered increased with temperature. Interestingly, males were more sensitive to cold temperature and flew significantly shorter distances than females at 21 and 25°C. Barometric pressure recorded before and during the flight mill experiment suggested that decreasing pressure reduced distance flown by D. citri. Flight direction was strongly influenced by wind. In wind tunnel experiments where psyllids were challenged to reach citrus leaf flush positioned either downwind or upwind, most D. citri moved downwind when exposed to continuous airflow. In a subsequent experiment, we challenged psyllids to pulsed wind blowing at higher speeds. In this case, most psyllids progressed upwind, suggesting upwind movement by psyllids during pauses within pulsed airflow. Collectively, the results indicate that D. citri are able to modify their flight behavior in response to abiotic factors.

The cabbage maggot (also known as cabbage root fly [CRF]; Delia radicum L.) is a serious pest of brassicas. The pest's soil-dwelling larvae are especially damaging to young brassica transplants. In light of toxic soil insecticide phase-out novel biocontrol management solutions are sought for. Our research is focused on the development of a biological control strategy involving cauliflower plantlet inoculation with insect pathogenic fungi. This article presents the results of a laboratory investigation of cauliflower × microbe × CRF interactions. Seven isolates of fungi (entomopathogenic and rhizosphere-competent fungi and soil saprotrophs) were tested for their pathogenicity to CRF and their effects on cauliflower plantlets. The laboratory experiments were performed in sterilized substrate. Several strains significantly increased CRF mortality, some at par with a commercial bioinsecticide based on B. bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae). All strains colonized the rhizoplane, however to varying extent. Some isolates were also reisolated from within healthy plant tissues and thus identified as endophytes. The method of applying conidia had a significant effect on survival and weight of seedlings and rhizoplane and endophytic colonization rates. Two Metarhizium brunneum Petsch (Hypocreales: Clavicipitaceae) isolates exhibited plant growth promotion effects when ungerminated seeds were coated with conidia. The ecological implications of plant × microbe × pest interactions and options for improving the effectiveness of a fungal-based biological CRF management strategy are discussed.

Xylotrechus arvicola (Olivier) (Coleoptera: Cerambycidae) is an important pest in vineyards (Vitis vinifera) in the main wine-producing regions of Spain. Effective control of this pest is difficult due to the biology of this pest. Biological control agents (BCAs) have proven to be an effective tool in controlling and preventing the spread of a variety of plant pests and diseases. Consequently, the aim of the present study was to assess the capacity of different Trichodema spp., isolated from various vineyards and one commercial isolate of Beauveria bassiana Vuillemin (Hypocreales: Cordycipitaceae), as BCAs of X. arvicola. Isolates of Trichoderma spp. and one isolate of B. bassiana were evaluated against X. arvicola eggs, larvae and adults. Trichoderma harzianum and Trichoderma gamsii demonstrated a good ovicidal control, 100.0% with T. harzianum and over 92.0% with T. gamsii. These Trichoderma strains achieved an over 65.0% larval mortality and 87.5% adult mortality. B. bassiana was the most effective treatment against X. arvicola larvae.These results confirm that Trichoderma spp. can be used to inhibit egg development. In addition, Trichoderma spp. and B. bassiana can help to prevent larvae boring into vines and to kill adults. Therefore, Trichoderma spp., especially T. harzianum and T. gamsii, and B. bassiana can be considered as highly effective BCAs of X. arvicola in vineyards.

Entompathogenic nematodes are found worldwide in a wide array of soil habitats with a broad host range and significant variation in foraging strategies. The primary use of entomopathogenic nematodes (EPNs) in managed plant systems has been focused on inundative releases in a biopesticide strategy. Little effort has been placed in investigating the use of natural occurring or adapted EPN strains for long-term suppression of pest outbreaks in managed systems. This study examined the potential of EPN isolates from Northern New York (NNY), inoculated at a low level (250 million IJ/ha), which are climate adapted and their persistent characteristics preserved to maintain population levels in agricultural fields (N = 82) for multiple years and across crop rotation (alfalfa:corn:alfalfa). Persistence levels for Steinernema carpocapsae (Weiser) (Rhabditida:Steinernematidae) ranged between 8 and 12% of the soil cores assayed in continuous alfalfa and 1–14% of the soil cores assayed in continuous corn rotated from EPN treated alfalfa. Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) residual persistence level ranged between 17 and 32% in continuous alfalfa and 22–41% in continuous corn rotated from EPN treated alfalfa. Combined EPN level ranged between 27 and 43% of the soil cores in continuous alfalfa and 28–55% in continuous corn rotated from EPN-treated alfalfa. Inspection of individual fields suggested EPN populations established in prior years at the residual soil core level of 18–35% can respond positively to an increase of susceptible hosts in both alfalfa and corn, often increasing their presence to 100%.

Aphids are important agricultural pests because of their feeding and, for many species, their ability to transmit plant pathogenic viruses. Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important predator in northern China of many aphid species, including Aphis craccivora (Koch) (Hemiptera: Aphididae). We measured the functional response and intraspecific competition of O. sauteri under different densities of A. craccivora at several constant temperatures. Predation of O. sauteri on A. craccivora conformed to Holling's type II functional response at all temperatures tested. The predation capability of O. sauteri showed a significant correlation with temperature. The predation capacity of O. sauteri was highest at 25°C, at which temperature we found the highest instantaneous attack rate (a = 0.8711), the theoretical maximum number of aphids captured (181.36), and the shortest handling time (T_h= 0.0055). Predation by O. sauteri increased progressively with temperature from 15 to 25°C, but then decreased at 30°C. Intraspecific competition of O. sauteri increased positively with predator density under all temperatures examined. Our results indicate O. sauteri has significant potential for use as a biocontrol agent, under a wide range of temperatures. The inverse density-dependent predation and intraspecific competition of O. sauteri suggests that to obtain the greatest degree of pest suppression, releases of O. sauteri should begin early in the cropping season and numbers released should take prey density into consideration.

Rapid population growth and wide host range make Habrobracon hebetor Say (Hymenoptera: Braconidae) highly suitable for biological control programs. To improve performance of the reared wasps in biological control programs we conducted a series of experiments on the effect of mating and carbohydrate feeding on life-history traits of this parasitoid. Mating caused a significant cost to fecundity, host paralysis and parasitism ability of H. hebetor. Mated wasps produced 30.98 and 23.2% less progeny than virgin wasps in unfed and fed treatments, respectively. Carbohydrate feeding increased survival only in the absence of host larvae. Virgin wasps produced only male offspring while the sex ratio produced by mated females was close to 50/50 for both fed and unfed wasps. Virgin wasps demonstrated an aggressive parasitism behavior and significantly higher paralysis and parasitism rates compared to mated wasps. Virgin wasps fed with carbohydrate found significantly more hosts than unfed wasps. To conclude, mating disruption in H. hebetor resulted in an aggressive parasitism behavior in the laboratory, which may also occur in the field. Therefore mating disruption is expected to improve the efficacy of these parasitoids in biocontrol. Carbohydrate feeding only improved searching ability and host allocation and could be applied in situations where hosts are highly dispersed.

The efficacy of a new and highly virulent Metarhizium anisopliae (Hypocreales: Clavicipitaceae) strain was evaluated against Blattella germanica (L.) (Blattaria: Blattellidae) in the laboratory; this strain was obtained and purified from field-collected Eupolyphaga sinensis cadavers. The status of this fungus as a new and genetically distinct species was supported by ITS sequence comparisons. The new strain was compared with other M. anisopliae isolates and was found to be highly infectious and virulent against B. germanica.The virulence of this new strain against different instars of male and female cockroaches at five conidia concentrations (1 × 10⁵, 1 × 10⁶, 1 × 10⁷, 1 × 10⁸, and 1 × 10⁹ conidia/ml) was evaluated in vitro, and the mortality (measured as lethal concentrations, LC₅₀) was determined. According to the pathogenicity test, M. anisopliae isolate EB0732 produced 100% mortality of one- to three-instar nymph (LC₅₀ = 0.37 × 10⁵conidia/ml) and 78.33% mortality of adult female (LC₅₀ = 1.39 × 10⁷ conidia/ml) at 15 d post-inoculation at a concentration of 1 × 10⁹ conidia/ml. There was an overall significant effect on mortality between the age and sex of B. germanica. A M. anisopliae susceptibility test showed that the survival rate of cockroaches after treatment with topical applications and mixed infection was lower than per os. These studies shed light on a valuable integrated pest management against the German cockroach.

Beneficial arthropods provide important ecosystem services in terms of arthropod pest and weed management, but these services can be adversely affected by farming practices such as tillage.This study investigated the impact of two tillage operations (zone tillage and moldboard plow) on the activity density of several beneficial, epigeal arthropod taxa, and postdispersal weed seed and prey removal in sugar beet agroecosystems. In addition, four omnivorous ground beetle species were selected for a weed-seed choice feeding assay, whereas a single species was selected for a weed-seed age preference assay. Ground beetles were the most commonly collected taxon (via pitfall sampling), with only a few dominant species. Tillage operation did not affect ground beetle activity density; however, spider, centipede, and rove beetle activity densities were higher in the reduced-tillage treatment. Live prey consumption was similar between tillage practices, with more prey consumed during nocturnal hours. More weed seeds were consumed in the reduced-tillage treatment, whereas weed-seed preference differed between the four weed species tested [Setaria pumila (Poir.) Roem. & Schult., Echinochloa crus-galli (L.), Kochia scoparia (L.), and Chenopodium album (L.)]. In the weed-seed choice feeding assay, significantly more broad-leaf weed seeds (C. album and K. scoparia) were consumed compared with grassy weed seeds (E. crus-galli and S. pumila). No preference for seed age was detected for E. crus-galli, but Harpalus pensylvanicus (De Geer) preferred old C. album seeds over fresh seeds. Zone tillage is compatible with ecosystem services, providing critical habitat within agricultural ecosystems needed to conserve beneficial, edaphic arthropods.

Cold tolerance studies were conducted with the egg and larval stages of Mediterranean fruit fly, Ceratitis capitata (Wiedemann) and melon fly, Zeugodacus (Bactrocera) cucurbitae (Coquillett) in Navel oranges to determine whether quarantine cold treatments approved for C. capitata might also be effective against Z. cucurbitae. Navel orange is a good host for C. capitata and a poor host for Z. cucurbitae, and therefore, artificial infestation of fruit was used to facilitate comparisons. Laboratory-reared eggs and larvae were inserted in the center of Navel oranges, placed in cold storage chambers at 1.5–2.0°C for 1, 2, 4, 6, 8, 10, 12, or 14 d, then removed, and evaluated for egg hatch or larval survival. Time-response data were analyzed using linear mixed-effects models, probit analysis, and visual inspection of survivorship graphs. C. capitata eggs were significantly more cold tolerant than Z. cucurbitae eggs, and Z. cucurbitae larvae were generally more cold tolerant than C. capitata larvae. C. capitata eggs and Z. cucurbitae second instar larvae were the most cold-tolerant life stages, and they were not significantly different from each other. Results suggest that cold treatment at ≤⃒1.5°C for a minimum of 14 d would be sufficient to achieve disinfestation of C. capitata and Z. cucurbitae. The inherent cold tolerance in Z. cucurbitae is equal to or higher than that of C. capitata, and therefore, cold treatment protocols developed for C. capitata may not always be effective against Z. cucurbitae.

The litchi moth, Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae), is endemic to sub-Saharan Africa and certain Indian Ocean islands. It is an important pest of litchis and to a lesser extent macadamias. Litchis are exported to certain markets that consider C. peltastica as a phytosanitary pest. Consequently, an effective postharvest phytosanitary treatment is required. This study sought to develop a cold disinfestation treatment for this purpose. First, it was established that the fifth instar was the most cold-tolerant larval stage, as it was the only instar for which there was still some survival after 12 d at 1°C. It was then determined that cold treatment trials could be conducted in artificial diet, as there was no survival of fifth instar C. peltastica in litchis after only 9 d at 1°C, whereas it took 15 d at this temperature before no survival of fifth instar C. peltastica was recorded in artificial diet. Consequently, cold susceptibility of fifth instar C. peltastica and the most cold-tolerant larval stages (fourth and fifth instar) of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), were compared in artificial diet. There was no survival of C. peltastica after 13 d at 1°C, whereas this was only so for T. leucotreta after 16 d. Consequently, it can be concluded that any cold treatment that has been proven effective against T. leucotreta would be as effective against C. peltastica. Finally, it was confirmed that the cold susceptibility of T. leucotreta in artificial diet did not overestimate the effect of cold on T. leucotreta larvae in litchis.

The insecticidal activity of phosphine (PH₃) and ethyl formate (EF) toward Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and their phytotoxicity to asparagus were evaluated. Both the PH₃ and EF fumigants showed higher lethal concentration and time (LCT) values at lower temperatures. The LCT₉₉ values of PH₃ and EF at 5°C in a 12 liters desiccator for 4 h showed the following ranking: eggs (64.69 mg·h/liter for PH₃ and EF indicating phytotoxicity to asparagus), nymphs (5.54 and 17.48 mg·h/liter, respectively), and adults (3.83 and 14.67 mg·h/liter, respectively). The adsorption of PH₃ was approximately 11% at 2°C and 13% at 5°C, whereas the adsorption of EF increased sharply to 88% at 2°C and 97% at 5°C. The hatching rate of F. occidentalis eggs was approximately 95% at all locations (top, middle, and bottom) in the presence of 4 mg/liter PH₃ at 5°C in a 0.65-m³ fumigation chamber for 24 h. However, extension of the treatment to 48 h resulted in 100% inhibition of egg hatching. The atmospheric level of PH₃ decreased below the threshold limit value after 80 min, and phytotoxicity was not observed. The results revealed that EF is highly absorbed by asparagus and is not suitable as a fumigant, but PH₃ is a suitable alternative to the fumigant methyl bromide for the control of western flower thrips in asparagus.

Ruspolia differens Serville (Orthoptera: Tettigoniidae) is an insect with significant economic potential in Africa. However, to mass-rear this species on a large scale, the optimal rearing temperature needs to be determined. We assessed multiple performance traits for R. differens reared at seven constant temperatures, ranging from 18 to 32°C, from newly hatched nymphs to 3 wk after adult molting. The highest observed survival was at 30°C (mean survival of 86.7%), where also the development rate reached its maximum. At this temperature, the development from newly hatched nymphs to adults took approximately 49 d. The weight of individuals at the time of adult molt reached its maximum at 28°C (mean weight of 0.62 g). To maximize the yield from mass-rearing, suggested time to harvest R. differens is 10 d after the adult molt. According to our results, during this time period R. differens individuals can achieve up to 50% higher weight than if harvested immediately after adult molting. For maximal survival and weight gain, we recommend rearing temperature of 28–30°C, whereas a slightly higher temperature of 31°C leads to the shortest development time. Taking into account all the performance traits, the overall optimal temperature is estimated at 29°C. Our results can be used when developing large-scale, mass-rearing protocols for R. differens in controlled temperatures.

Maternally-inherited facultative symbionts are widespread in most insect species, and it is common that several symbionts coexist in the same host individual. Hence, the symbionts may compete or share for the limited resources and space in the host. The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodoidea), harbors a diverse array of facultative symbionts, among which Hamiltonella sp. and Cardinium sp. are abundant species. Hamiltonella alone increases host fitness, while Cardinium alone confers lower fitness. Locking those different partners together creates ideal situations for the evolution of interactions between symbionts. In this study, we compared the fitness effects of whiteflies infected with only Hamiltonella to Hamiltonella-Cardnium co-infected whiteflies and measured the density of Hamiltonella and Cardinium during host aging, aiming to explore Hamiltonella-Cardinium interactions in B. tabaci. Our results illustrated that Hamiltonella-Cardinium coinfection induced lower fecundity, egg hatchability and number of female offspring, leading to a male-biased sex ratio in offspring, while there is no evidence for reproductive incompatibility between the infections. We also found an antagonistic interaction between Hamiltonella and Cardinium given that the density of the latter increased across time and led to a decrease of Hamiltonella density, which may be the underlying causes of the fitness cost in double-infected B. tabaci. Exploring the ecological consequences of co-infections of these different symbionts helps us to understand the nature of host-symbiont interactions in this species and potential for evolutionary conflict.

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of tomato worldwide. Biological control of the pest using Trichogramma (Hymenoptera: Trichogrammatidae) wasps can be combined with other practices such as use of synthetic sex pheromones for mating disruption or mass trapping programs. In this study, effects of T. absoluta sex pheromone on behavioral responses and fertility life table parameters of Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae), Wolbachia-uninfected (W⁻) Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae), and Wolbachia-infected (W⁺) T. brassicae were investigated under laboratory conditions. Female wasps of T. evanescens and T. brassicae (W⁺) were attracted to the pest synthetic sex pheromone (around 62%) and calling virgin female moths (around 75%) and their responses were affected by the wasp age and temperature. Exposure to the host synthetic sex pheromone significantly reduced the percentage of adult emergence, longevity, and fecundity of female wasps, as well as the time spent to find a mate and duration of mating. However, tested populations were not affected similarly. Despite the laboratory tests, greenhouse experiments showed that the wasps were not caught in the traps baited with T. absoluta synthetic sex pheromone. Complementary studies are needed to precisely determine possible interference between pheromone application and releasing Trichogramma Westwood (Hymenoptera: Trichogrammatidae) wasps to achieve a successful integrated control of T. absoluta.

The black soldier fly [Hermetia illucens L. (Diptera: Stratiomyidae)] can be sustainably reared on organic waste streams and thereby provide a novel animal protein source for animal feed. Black soldier fly's performance and body composition depend to a large extent on the nutrient composition of the waste stream. Black soldier fly larvae were fed on four diets consisting of vegetable by-products from the food industry. All four diets contained dried distiller's grains with solubles plus one or two other main ingredients; for diet 1 the additional ingredient was grape pulp; diet 2: potato peels; diet 3: bean seeds; and diet 4: cabbage leaves plus old bread. The diets were formulated based on an optimal summed protein and carbohydrate (P+C) concentration resulting from previous experiments and a 1:2 protein:carbohydrate (P:C) ratio. We quantified both larval and adult performance. Diet 4 was the best performing vegetable waste-based diet. In a follow-up experiment, we re-formulated diet 4 to have P:C ratios of 1:2 or 1:3 and 40 or 47% dry matter of P+C. In the first experiment, although there were differences in larval performance among the diets, all diets supported a higher larval performance than reported previously, with diet 4 having 47% P+C being the best performing diet. We infer that not only total macronutrient content but also nutritional quality of proteins and carbohydrates affected performance. In the second experiment, the two vegetable residue-based larval diets resulted in similar larval and adult performance. High dietary protein resulted in increases in larval crude fat content.

Delottococcus aberiae (De Lotto) (Hemiptera: Pseudococcidae) is the most recent species of mealybug introduced to Spain that is affecting citrus. The feeding behavior of D. aberiae causes severe direct damage to citrus fruits, distorting their shape and/or causing reduction in size. There is no information available regarding its distribution within the citrus trees. The main objective of this study was to describe the seasonal distribution of D. aberiae within citrus trees and its migration patterns on the plants.Ten citrus orchards from eastern Spain were periodically sampled during 3 yr. In each orchard, the mealybug was sampled in different infested strata (canopy, trunk, and soil) and canopy structures (flower, fruit, leaf, and twig). Results showed that, within the sampled strata, D. aberiae was mostly in the canopy. Within the canopy, the feeding location of D. aberiae changed throughout the year. D. aberiae overwintered in the twigs and moved to the flowers and fruits in spring. Once there, its populations started to increase exponentially until August. From February to September, 5–30% of the mealybugs migrated to the trunk and soil. These results will facilitate an early detection of the pest in the areas where it is spreading and improve sampling protocols and pesticide applications.

To obtain insects with biological characteristics similar to those of wild insects, this study evaluated the development of Diatraea saccharalis (Fabricius) reared on artificial diet containing different sugar concentrations. First-instar caterpillars were fed seven artificial diets containing 0, 6.56, 13.13, 26.26, 52.52, 105.04, and 210.08 g of sugar per liter of diet. We evaluated the duration and viability of developmental stages, weight of pupae, fecundity and longevity of generations F₁, F₂, F₄, F₆, and F₈. The artificial diet containing 26.26 and 52.52 g of sugar per liter provided the greatest viability of insects (above 75%) for the egg-adult period for eight consecutive generations, and was higher (P < 0.05) than other treatments, where viability was lower than 50%. Based on the fertility life table in F₈ generation, the highest reproductive rates (Ro) were obtained in insects fed the artificial diet containing 26.26 (Ro = 126.39) and 52.52 g of sugar (Ro = 147.31). Conversely, insects to other diets presented the highest values of biological cycle duration (T = 55 d) and reductions of 50 and 90% on intrinsic rate of increase (r_m = 0.0063, 0.079, 0.077, and 0.064) and finite rate of increase (λ = 1.001, 1.082, 1.081, and 1.006), respectively. We conclude that sugar is essential for the development of D. saccharalis and that amounts of 26.26 and 52.52 g per liter of diet are suitable for the rearing and multiplication of insects in laboratory.

The antifeedant and contact toxicity of Sphagneticola trilobata L. (Asterales: Asteraceae) extracts and isolated alkane compounds were investigated. Leaves of S. trilobata were sequentially extracted with hexane, dichloromethane, ethyl acetate, and methanol. Each extract and the compounds isolated were evaluated against the third instars of Spodoptera litura (F.) (Lepidoptera: Noctuidae), Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), and Plutella xylostella L. (Lepidoptera: Yponomeutidae). Ethyl acetate extract and isolated alkanes were feeding deterrents as well as contact toxins against all the three species evaluated (FI50 ∼ 0.27–2.34 mg/ml; LD50 ∼ 0.88–4.2 μg/larvae for ethyl acetate extract, and FI50 ∼ 0.06–4.35 mg/ml; LD50 ∼ 0.72–3.54 Ethyl acetate extract for isolated alkane). Impact on detoxifying enzymes was variable. The ethyl acetate crude extract reduced carboxylesterase activity in S. litura and P. xylostella while in S. exigua the enzyme was induced. In contrast, glutathione-S-transferase activity was induced in S. exigua but no significant difference in P. xylostella and S.litura was observed. Our results suggest that the S. trilobata extracts have multiple biological activities that contribute to the toxicity in lepidopterans. Variable enzyme responses to the products evaluated in different lepidopteran species also confirm that some speciesspecific inductions do occur, suggesting the possibility of resistance development in the future, which cannot be summarily ignored. However, for this detailed biochemical studies are required. Multiple bioefficacies of S. trilobata makes it a potential botanical for further exploitation on larger scale so that field potential can be established in any integrated pest management (IPM) system.

Cantharidin is a highly potent toxin produced by insects belonging to the order Coleoptera and family Meloidae. The insecticidal activity of cantharidin against different orders of insects has been well documented. Although it is highly effective, its extraction and synthesis is very tedious. Consequently, much work is underway to synthesize the bioactive analogs of norcantharidin and study their relative structures. In this study, we investigate the acute and chronic toxicological effects of cantharidin and endothall, an analog of norcantharidin, using an age-stagebased two-sex life table methodology. Results reveal the acute toxicity of these compounds to Spodoptera litura Fabricius (Lepidoptera: Noctuidae), with the LC₅₀ of cantharidin being 2.10 and endothall being 3.72 ppm, after 72 h posttreatment. Although both the compounds negatively affected the intrinsic rate of population increase (r), finite rate of increase (λ), net reproduction rate (R₀), mean generation time (T), doubling time (DT), relative fitness (R_f), biotic potential, and longevity, cantharidin was slightly more effective. Among the reproductive parameters, fecundity was severely affected by cantharidin, which reduced offspring to 42 compared to 528 per female in the control cohort. Both cantharidin and endothall caused similar physiological changes such as weight reduction, wing malformation, and pupal deformities. These findings demonstrate that both cantharidin and endothall are highly toxic to S. litura, particularly in their chronic effects on population parameters. This will help us to understand the biological and ecological interactions in agricultural cropping systems and how their application will modify insect herbivory.

Field experiments were conducted in 2016 and 2017 in Tennessee to evaluate the effects of a novel Bacillus thuringiensis (Bt)-transgenic toxin, Bt Cry51Aa2.834_16, on thrips (Thysanoptera: Thripidae) and tarnished plant bug, Lygus lineolaris (Palisot De Beauvois) (Hemiptera: Miridae), in cotton. Protection from thrips injury with the Bt trait was as good or better than an insecticide-based approach. The use of the Bt trait resulted in reduced numbers of immature tarnished plant bug, particularly large nymphs, and partial protection from plant bug injury. Cotton that expressed Bt Cry51Aa2.834_16 had greater yields than the non-Bt isoline when insecticides were not used. Although Bt Cry51Aa2.834_16 reduced the need for insecticide applications, foliar-applied insecticide applications were needed to provide adequate plant protection from tarnished plant bug. The currently recommended treatment thresholds for tarnished plant bug performed similarly well for Bt Cry51Aa2.834_16 and non-Bt isolines. Insecticide applications for tarnished plant bug increased fiber quality, while Bt Cry51Aa2.834_16 had minor effects. The Bt-transgenic toxin Cry51Aa2.834_16 is expected to reduce the need for insecticide applications targeting thrips and tarnished plant bug and could be a valuable addition to an overall insect management program in cotton.

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is considered the most important maize (Zea mays L.) pest in the U.S. Corn Belt. Bioassays testing susceptibility to Bacillus thuringiensis Berliner (Bt) and other toxins of corn rootworm larvae often rely on artificial diet formulations. Successful bioassays on artificial diet for corn rootworm have sometimes been challenging because of microbial contamination.Toward the long-term goal of developing a universal artificial diet for western corn rootworm larvae, we compared larval survival, dry weight, and percentage of molt in 10-d bioassays from six current diets of which we were aware. In addition, as part of longer term rearing efforts, we recorded molting over an extended period of development (60 d). Six different artificial diets, including four proprietary industry diets (A, B, C, and D), the first published artificial diet for western corn rootworm (Pleau), and a new diet (WCRMO-1) were evaluated. Western corn rootworm larval survival was above 90% and contamination was 0% on all diets for 10 d. Diet D resulted in the greatest dry weight and percentage molting when compared with the other diets. Although fourth-instar western corn rootworm larvae have not been documented previously (only three instars have been previously documented), as many as 10% of the larvae from Diet B molted into a fourth instar prior to pupating. Overall, significant differences were found among artificial diets currently used to screen western corn rootworm. In order for data from differing toxins to be compared, a single, reliable and high-quality western corn rootworm artificial diet should eventually be chosen by industry, academia, and the public as a standard for bioassays.

Several species of aphids (Hemiptera: Aphididae) infesting wheat may reduce yield by the transmission of barley yellow dwarf (BYD). Neonicotinoid seed treatments and foliar application of insecticides are two common methods to control aphid infestations and reduce BYD. An analysis was carried out across 33 insecticide efficacy tests performed in west Tennessee during the last 11 yr to determine how insecticide seed treatments and/or a late-winter foliar insecticide application affected aphid populations, incidence of BYD, and yield. A significant decrease in springtime aphid populations and incidence of BYD was observed when using a seed treatment, a foliar insecticide application, or both. Average wheat yields were increased by 280–381 kg/ ha (5.3–7.2%) if an insecticide seed treatment was used or when a foliar insecticide application was made. Compared with insecticide seed treatments, average springtime aphid populations and the incidence of BYD were lower when a foliar insecticide was applied. A foliar insecticide application made in addition to insecticide seed treatments increased yield by an average of 196 kg/ha (3.4%). The yield increases over the nontreated control suggest that wheat growers in west Tennessee can use insecticides to manage aphids and prevent transmission of BYD. Consideration of environmental conditions, whether or not insecticide seed treatments were used, and scouting can be used to help make decisions on when or if to apply foliar insecticides.

To favor and standardize fruit fly production, many environmental factors are regulated in a mass-rearing facility. Specifically, in the holding rooms where sterile fruit flies are kept before releasing, they are exposed to constant darkness in order to reduce aggressive interactions and depletion of energy resources. However, such light conditions could negatively affect the quality traits and male mating performance. The objective of this study was to determine whether light conditions have an effect on quality traits in mass-reared ‘Mediterranean fruit flies’ Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Under laboratory conditions and in two sequential experiments, we studied the effect of 1) different light intensities and 2) photoperiods, on adult food consumption, adult body weight, survival, and percent of flying and calling males. In the first experiment, sterile male flies were exposed to different light intensities during 3 d after emergence: 1000, 500, or 250 lux, with a 12:12 photoperiod. Complete darkness was used as a control. In the second experiment, adult flies were exposed to the following photoperiods (L(1000 lux)-D): 14-10, 12-12, 8–16, 4–20, and 0–24 as a control. Our results showed that flies under darkness ingested less food, were heavier, and exhibited higher survival than flies under any treatment of light intensity or photoperiod. Furthermore, the percentage of fliers and number of calling males did not differ among treatments. We conclude that holding males for 3 d under darkness do not affect their quality; indeed, emerging under this condition appears to favor them. The implications of these findings for SIT programs are discussed.

Efficient, economic, and simple monitoring methods are important to develop successful integrated management for Asian citrus psyllid (ACP) especially in developing countries.Two 5-wk tests were carried out to study the capture of ACP adults using yellow sticky traps by adding commercial citrus fruit scents (lemon, tangerine, or orange) or commercial coconut oil (first test) and to compare these baits with commercial lures (Alpha Scents and Pest Wizard) (second test) under natural infestation conditions. In the first test, the following treatments were carried out: yellow sticky traps baited with 1) coconut oil; 2) lemon, tangerine, or orange commercial scents; or 3) unbaited yellow sticky tramps (control). In the second test, treatments were as follows: traps baited with 1) coconut oil; 2) lemon, tangerine, or orange commercial scents; 3) two different commercial lures (Pest Wizard and Alpha Scents); and 4) unbaited traps. In the first experiment, the results obtained showed that traps with a coconut oil lure captured 4.4 ACP adults per trap per week, whereas control traps caught 1 ACP adult. In the second test, coconut oil (4.5 adults per trap per week) and Alpha Scents (4.2 individuals) lures also exhibited a higher capture in comparison to all citrus scents (3.1 individuals) and Pest Wizard (3.5 individuals), and control (2 individuals). In conclusion, these results suggest that the use of commercial attractants, mainly coconut oil, can be more attractive than unbaited traps and this may be helpful for integrating into integrated pest management programs intended for ACP.

Leafrollers are polyphagous pests whose larvae damage fruit and cause market access problems for fruit crops exported from New Zealand. Leafroller larvae and pupae were collected mainly from four fruit crops, but also from hedges, ornamental trees, and understory weeds in orchards and vineyards of Hawke's Bay, a major fruit production region. Samples were collected from 1974 to 1977 and 1993 to 2015. This timespan was divided into periods that broadly coincided with broad-spectrum insecticide management, the transition to selective insecticides, and the full implementation of integrated fruit production (IFP) programs in apples, grapes, and stone fruit. Eight tortricid species were identified, but the accidentally introduced Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) and two native species, Ctenopseustis obliquana (Walker) and Planotortrix octo Dugdale, comprised 95% of the samples. The proportions of these three species varied according to interactions between four factors: pest management regime, collection period, property location, and host plant. In the 1970s under broad-spectrum insecticide programs, the native species dominated on all hosts. By the mid-late 1990s when IFP was introduced, all the main leafroller species were in decline. However, E. postvittana declined to a lesser extent than the two native species, and consequently, it became relatively more prominent.This change in species composition was delayed in two districts where localized cases of organophosphate insecticide resistance occurred in C. obliquana and P. octo. From 2000 onwards, E. postvittana was the dominant species in all districts and on all hosts, albeit with a much-reduced pest status, except on hedges and ornamental trees where C. obliquana prevailed.

A new sterile insect technique (SIT) program is currently being developed for management of the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), the most costly challenge to Australian horticulture in the eastern states. SIT relies on cost-effective mass production of millions of high-quality flies. A recently developed gel larval diet has proven effective, enabling production of large numbers of high-quality flies, but includes some costly ingredients. With a basic diet now available, current research focuses on refining the formulation to deliver a more economical diet. Wheat germ oil (WGO) is the main lipid source in the current Queensland fruit fly gel diet, but is a particularly expensive ingredient and has limited availability. To identify an oil that maintains high productivity and fly quality at reduced cost, the present study assessed production and performance of Queensland fruit flies reared on gel larval diets containing the WGO that was used in previous studies (WGO/M), an alternative WGO (WGO/A), sunflower oil, rice bran oil, and canola oil. Diets containing canola oil ($5.24/liter) performed as well as diets with WGO/M ($116/liter) in terms of parental egg hatch, pupal number, pupal weight, adult emergence, percentage and rate of fliers, sex ratio, fecundity, and fertility (F1 egg hatch), offering a remarkably cost-effective alternative. Costs of oil in Queensland fruit fly production are reduced by ca. 95% per 1,000 flight capable adults (‘fliers’). Substantial savings may be made in Queensland fruit fly mass rearing by substituting WGO/M with canola oil in gel larval diets without compromising productivity.

Boric acid has been used as an insecticide in the successful control of agricultural, public health and urban pests long before the advent of synthetic organic pesticides. Boric acid products, formulated as dusts, sprays, granular baits, pastes, gels, and liquids, are widely available to consumers and pest management professionals, especially to control pest infestations within homes. Boric acid dust is commonly used against bed bugs (Cimex lectularius L. [Hemiptera: Cimicidae]), but its efficacy has not been demonstrated. We evaluated the efficacy of boric acid as an ingestible and residual contact insecticide on bed bugs, and compared its efficacy on the German cockroach (Blattella germanica L. [Blattodea: Ectobiidae]) which is known to be susceptible to boric acid by both routes. Dose–response studies of 0–5% boric acid in blood demonstrated that ingested boric acid caused rapid mortality at concentrations of ≥2%, and even 0.5% and 1% boric acid caused 100% mortality, albeit at a slower time course. In contrast, bed bugs survived contact with high concentrations of boric acid dust. Smaller boric acid particles did not increase mortality of either unfed or recently fed bed bugs. The same boric acid products were effective at causing mortality of German cockroaches by both contact and ingestion. We thus conclude that although boric acid is an excellent candidate active ingredient for an ingestible bait formulation, residual applications of dust or spray would be ineffective in bed bug interventions.

RNA interference insecticides have received increasing attention in recent years due to their classification as a reduced-risk biopesticide and their proposed faster path to registration compared with conventional synthetic insecticides. The goal of this study was to synthesize and compare efficacy of 62 double-stranded RNAs (dsRNAs) from 31 target genes against the pest termite species, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae). Fifty-seven dsRNAs of ~125 base pairs each were successfully synthesized. First-tier screens using a combination immersion/feeding assay revealed 10 top candidates and also that dsRNAs coming from synthesis reactions with 80–90× yields were the most effective. Follow-up studies using uptake enhancers in combination with top candidate dsRNAs were unsuccessful. Subsequent concentration range feeding assays on the top candidates revealed two lead termiticidal dsRNAs (3 Hexamerin-2 and 3 Glycosyl Hydrolase Family [GHF] 9-2 cellulase) and another that enhanced feeding (5 GHF9-2 cellulase).Testing a matrix of combinations of these three dsRNAs revealed ultimately that the most consistently effective dsRNA combination was the 3 Hexamerin-2 + 3 GHF9-2 cellulase dsRNA combination. These results provide new information on candidate termiticidal dsRNAs and some apparent factors that have a bearing on their efficacy. Despite these successes, further research and development will be necessary to move dsRNA termiticides from pest management theory to real-world application.

German cockroaches, Blattella germanica (L.) (Blattodea: Ectobiidae), are important indoor insect pests and remain difficult to control because of their ability to develop resistance to insecticides. The toxicity, resistance levels, repellency, and performance index (PI) value of five formulated insecticides (permethrin, chlorpyrifos, propoxur, imidacloprid, and fipronil) were determined for adult males of seven strains of the German cockroach: a laboratory-reared susceptible strain (S) and six field-collected strains (B, D, E, G, H, and I). Propoxur was generally the most toxic insecticide to all strains using continuous exposure methods; however, using Ebeling choice box methods, chlorpyrifos, and fipronil were most toxic. In both continuous exposure and Ebeling choice box tests, the field-collected strains were generally most resistant to permethrin among the five insecticides. The greatest increase in resistance ratios between the two exposure methods was for permethrin and propoxur. Permethrin was the most repellent insecticide against all but two strains (D and H). PI values reached 100 (no repellency and complete mortality) for the susceptible strain against only chlorpyrifos and fipronil. Only fipronil resulted in a PI value of 100 for any of the field-collected strains. Continuous exposure and Ebeling choice box resistance ratios were correlated, and both were correlated with previously reported resistance ratios (based on LD₅₀ values). Choice box repellency, however, was only correlated with LD₅₀ resistance ratios. PI_Max was negatively correlated with all measures of resistance ratios.

A laboratory colony of tarnished plant bugs reared solely on a meridic diet was exposed to acephate, imidacloprid, permethrin, sulfoxaflor, and thiamethoxam in dose–response experiments using floral-foam, glass-vial, and dipped-leaf assays. Results indicated that different assay methods produced different relative results across the different insecticides. Dose- and time–response regression models also indicated that length of exposure of tarnished plant bugs to insecticide-treated plant tissue is important. Time of exposure required to reach an LC₉₀ at estimated recommended field rates suggested that the recommended lower field rate of acephate (0.56 kg ai/ha) would reach an LC₉₀ of exposed tarnished plant bugs between 48 and 96 h post initial exposure. An LC₉₀ of tarnished plant bugs exposed to permethrin (0.11 kg ai/ha) was not predicted from the regression modes over the 168-h observation; lower recommended application rates of imidacloprid (0.053 kg ai/ha), sulfoxaflor (0.053 kg ai/ha), and thiamethoxam (0.042 kg ai/ha) reached projected LC₉₀s between 96 and 168 h of exposure. Collectively, the results of this study corroborate current existing procedures for tracking tarnished plant bug resistance to insecticides, but also illustrate the importance of additional field studies that empirically associate assay results to projected field control.

The black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), has been considered a major insect pest in China that causes damage to corn at the seeding stage. The present study measured the lethal and sublethal effects of the neonicotinoid insecticide clothianidin on A. ipsilon. Clothianidin, incorporated using an artificial diet, exhibited signs of active toxicity on fourth-instar larvae of A. ipsilon, with a 50%-lethal concentration (LC₅₀) of 27.77 μg/g. Clothianidin at the LC₂₀ and LC₄₀ levels impaired the normal development of A. ipsilon by prolonging the larval period, decreasing the rate of pupation and eclosion, reducing longevity, shortening the oviposition period, and reducing the fecundity of female adults. Consequently, these effects resulted in the reduction of some population parameter values of A. ipsilon, including the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀), along with an increase in the mean generation time (T). However, stimulatory effects, i.e., hormesis, on reproduction were observed in A. ipsilon exposed to an LC₅ level based on the fecundity (2,213.62 eggs per female) and net reproductive rate (R₀) (863.04 offspring per individual), which were significantly higher than values in the control group (1,344.77 eggs per female and 591.82 offspring per individual). Therefore, the results obtained in this study may assist in the development of optimized integrated pest management strategies, although the results require further study for corroboration under real cropping conditions.

Cytochrome P450 monooxygenases (P450s) play important roles in metabolizing various insecticides and often contribute to the development of insecticide resistance in insects and other arthropod species. The objective of this study was to compare the metabolism of four commonly used pyrethroids including deltamethrin, fluvalinate, fenvalerate, and permethrin in the midgut tissue of Locusta migratoria Linnaeus (Orthoptera: Acrididae) by using synergism bioassay and ultra-performance liquid chromatography (UPLC)–mass spectrometer (MS) analyses. Our study showed that piperonyl butoxide (PBO, P450 enzyme inhibitor) can significantly synergize the toxicity of deltamethrin, fluvalinate, and fenvalerate with synergism ratios ranging from 1.30 to 1.70 folds. Preincubations of the midgut tissue with PBO followed by incubations with each of the four pyrethroids resulted in significantly higher amounts of unmetabolized deltamethrin and fluvalinate than those in the control (preincubation without PBO) as well as preincubations with other two detoxification enzyme inhibitors. These results indicate that P450s play important roles in metabolizing deltamethrin and fluvalinate in the midgut tissue. Our further study using deltamethrin as a representative pyrethroid and UPLC–MS techniques confirmed that the reduced amount of deltamethrin in the control (preincubation without PBO) was due to the metabolism of deltamethrin to yield hydroxydeltamethrin which is a major metabolite produced by P450-mediated aromatic hydroxylation of deltamethrim. These results provide new insights into differential metabolic activity of P450s towards different pyrethroids in the midgut tissue of L. migratoria.

Insecticidal efficacy of neonicotinoid insecticides used against tobacco thrips, Frankliniella fusca (Hinds) (Thysanoptera: Thripidae), in cotton, Gossypium hirisutum L. (Malvales: Malvaceae), was evaluated for field populations collected in Mississippi during 2014–2016. Resistance was documented in 16 and 57% of populations to imidacloprid and thiamethoxam, respectively. Resistance levels did not vary by host plant for any neonicotinoid, but resistance levels varied between the two main agricultural areas (Delta and Hills) of Mississippi and among years for some neonicotinoids. In spite of documented resistance, neonicotinoid seed treatments are still used on cotton in the midsouthern United States due to the lack of reliable alternative management strategies. The development of alternative thrips management strategies is critical to the sustainability of cotton production in the midsouthern United States.

Tetranychus urticae Koch is a generalist pest of economic crops and is notorious for its rapid development of acaricide resistance. This poses a significant threat to the sustainability of integrated pest management (IPM) in cropping systems plagued by T. urticae. It is critical to evaluate the resistance status of T. urticae populations on crops and identify any underlying resistance mechanisms. This study investigated the efficacy of five major acaricides on T. urticae populations on peppermint and silage corn in the Pacific Northwestern United States and identified the underlying resistance mechanisms. Significant variations in acaricide resistance status of T. urticae populations were identified to abamectin, bifenthrin, fenpyroximate, hexythiazox, and spirodiclofen. In most cases, T. urticae populations from silage corn exhibited greater levels of acaricide resistance relative to peppermint populations. We detected known target-site mutations: F1534S and F1538I (conferring resistance to bifenthrin), G126S (linked with resistance to bifenazate), and I1017 (conferring resistance to hexythiazox and etoxazole) in 10, 90, and 90% of the populations, respectively, from peppermint fields. These four mutations were identified in all the populations collected from silage corn fields. Significantly higher transcript levels of metabolic genes associated with resistance to abamectin, fenpyroximate, and spirodiclofen were observed in some T. urticae populations collected from both peppermint and silage corn fields.This study provides evidence of multiple resistance to diverse active ingredients in field populations of T. urticae and the reliability of known molecular markers for active acaricide resistance monitoring. The observed resistance pattern will help in designing a sustainable IPM program for T. urticae.

The emergence and intensification of resistance to insecticides in malaria vector populations is the main obstacle to insecticide-based control efforts. The main objective of this study was to evaluate the larvicidal and adulticidal properties of the essential oils (EOs) of Ocimum canum, Hyptis suaveolens, Hyptis spicigera, and Lantana camara on field-collected, pyrethroids-resistant mosquitoes, local laboratory strains, and susceptible ‘Kisumu’ strain of Anopheles gambiae (Meigen) (Diptera: Culicidae) populations. Larvae and adults of these mosquitoes were challenged against four EOs. The mortality rates of larvae and adults were assessed 24 h after exposure to the EOs. Species identifications and detection of the L1014F and L1014S kdr mutations and the 1575Y super-kdr mutation were carried out using polymerase chain reaction on the pyrethroid-resistant mosquitoes from the field. EO compositions were analyzed by gas chromatography and mass spectrometry. Monoterpene hydrocarbons were the major components of H. suaveolens and H. spicigera EOs (49.8%) and (69.6%), respectively, whereas oxygenated monoterpenes (68.7%) were predominant in the O. canum EO. For L. camara, the component yields were variable, but it was the most effective EO against all strains. The LC₅₀ values for the larvae were 7.73 and 25.63 ppm for the susceptible ‘Kisumu’ and resistant field strains, respectively. The LC₅₀ for adults was 0.24% for the susceptible strain and 1.98% for the resistant strain. Molecular analysis confirmed the presence of L1014F and N1575Y mutations in resistant Anopheles arabiensis and Anopheles coluzzii mosquitoes from the field. Our results highlighted the potential of the EOs of local plants as insecticides against resistant and susceptible strains of An. gambiae populations.

Aedes aegypti (L.) (Diptera: Culicidae) is the primary vector of several arthropod-borne viral infectious diseases globally. Relentless vector control efforts are performed to curtail disease transmissions, insecticides remain as the first line of defense in Indonesia. With a dearth of publication on the efficacy of mosquito coil in Indonesia, this is the first report related to mosquito coil despite its common use in households. Ae. aegypti mosquitoes were sampled from nine regencies in Indonesia and tested using the glass-chamber method against three commercially available local pyrethroid-based mosquito coils containing d-allethrin, transfluthrin, and metofluthrin. The 50% knockdown time of female Ae. aegypti tested with d-allethrin, transfluthrin, and metofluthrin containing coils ranged from 0.65 to 14.32; 0.8 to 16.4; and 0.78 to 20.57 min, respectively. Mortality rates in accordance with WHO resistance indicators showed that strains from Denpasar, Mataram, Kuningan, Padang, Samarinda, and Sumba Timur were resistant (<80% mortality rate), whereas strains from Manggarai Barat, Dompu, and Pontianak were susceptible (>98% mortality rate) to the active ingredients assayed. Moreover, the knockdown rates between d-allethrin and transfluthrin, d-allethrin and metofluthrin, as well as transfluthrin and metofluthrin displayed significant associations, portraying the presence of cross-resistance within pyrethroid insecticides. The minimal insecticidal effect of mosquito coils against some Indonesian Ae. aegypti also pointed out the development of pyrethroid resistance, prompting a revamping of the vector control system.

The oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most destructive agricultural pests and hosts diverse intestinal bacterial communities. We used 16S rRNA gene sequencing to investigate the microbial communities associated with the intestines of females and males from two B. dorsalis populations collected from Hainan and Guizhou Provinces of China. A total of 260,615 high-quality 16S rRNA gene reads with an average length of 253 bp were obtained. Highly diverse bacterial communities were observed across individuals, with communities containing between 691 and 1,262 bacterial operational taxonomic units. In addition, 37 bacterial phyla, 65 classes, 130 orders, 198 families, 201 genera, and 70 annotated species were identified, wherein the Proteobacteria were the most dominant phylum among all of the libraries, followed by the Firmicutes and Bacteroidetes. Bacterial community composition varied by host sex and geographic location of the populations. Female gut communities comprised fewer bacterial families than males, and females had lower relative abundances of 33 of the 35 most abundant families. In addition, female gut communities harbored greater abundances of Enterobacteriaceae than males. The Hainan population gut communities contained fewer bacterial families than those of the Guizhou populations. However, 5 of the 35 most abundant families were more abundant in communities from the Hainan population than those of the Guizhou population. The results of this study help us better understand the importance of symbiotic bacteria in B. dorsalis and provide a foundation for assessing the use of gut microorganisms as bio-control agents for these serious pests.

The brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a destructive rice pest of Asia. Currently, one important monitoring method of BPH is through black light trapping. However, two sibling species of BPH, Nilaparvata bakeri (Muri) and Nilaparvata muiri China, can also be trapped by black light, and these species feed only on gramineous weeds rather than on rice. Therefore, the accurate identification of Nilaparvata species is crucial for N. lugens forecasting and management. The traditional morphological identification method is not feasible for subadults and damaged specimens. Furthermore, this error-prone morphological identification method is time and labor intensive, with the need for expertise and experience. Here, we established a direct multiplex polymerase chain reaction (dmPCR) assay using crude tissue fluid as a template, omitting purified DNA extraction. The crude tissue fluid can be obtained by grinding specimens without any biological reagent but only using distilled water. This dmPCR assay, using three pairs of diagnostic primers, is based on internal transcribed spacers (ITS). Each primer pair amplifies a species-specific fragment of a different size, which were easily and reliably separated in a 2% agarose gel. Furthermore, the dmPCR was verified to be applicable to damaged tissue specimens, such as head, thorax, or abdomen. In conclusion, this dmPCR assay is a novel, time-saving, cost-effective, and easy-toapply molecular diagnostic method for the identification of the above three sibling species, N. lugens, N. bakeri, and N. muiri.

The silk gland (SG) is characterized by the synthesis and secretion of silk protein in the economically important silkworm, Bombyx mori L. (Lepidoptera: Bombycidae). Nd and Nd-s are two fibroin-secretion-deficient silkworm mutants. MicroRNA (miRNA) plays an important role in many biological processes, such as cell proliferation, differentiation, and apoptosis. Using the Dazao silkworm as a control, we explored the miRNA expression profiles in the SGs of u02 (Nd) and u05 (Nd-s) to reveal the potential functions of miRNAs in silk protein expression and SG development. Here, we sequenced small RNA libraries made from the whole SGs of three strains. There are 260, 236, and 233 known miRNAs and 20, 18, and 18 potential new miRNAs identified from Dazao, u02, and u05, respectively. Fifty-three miRNAs are differentially expressed between Dazao and u02, 51 between Dazao and u05, and 16 between u02 and u05. Gene ontology/KEGG analyses show that most of the predicted target genes of differentially expressed miRNAs were assigned to functional categories involved in cell proliferation, organ development, and cellular compartment structures. The miRNA expression profile of naked silkworms will pave the way for the understanding of SG development and the regulation of silk protein expression.

The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is a serious rice pest because of its destructive feeding. The salivary glands of the BPH play a key role in successful feeding. In this study, we explored the salivary gland transcriptome (sialotranscriptome) of adult BPHs using Illumina sequencing and a total of 55,913 transcripts and 45,421 unigenes were obtained. We identified one reference gene RPL9 (Ribosomal protein L9) and 19 salivary protein genes from the BPH sialotranscripome, which were categorized as those involved in sugar metabolism, extra-oral digestion of cell wall components, detoxification, and suppression of plant defenses. Tissue expression profiles of 19 salivary protein genes analysis revealed that the expression level of alpha-glucosidase family 31 had no difference in five tissues, suggesting that it may have functions in the whole-body parts. Glucose dehydrogenase (flavine adenine dinucleotide, quinone)-like was expressed highly in the salivary gland, which might play putative role in insect feeding. Glucose dehydrogenase (acceptor) was expressed the highest level in head without salivary gland. Other salivary protein genes were highly expressed in gut or malpighian tubule, suggesting that they may play roles in digestive and detoxification mechanism. Moreover, we detected RPL9 is one of the genes that is most consistently present for acquisition of gene expression in different tissues. Thus, RPL9 can be a new reference for expression studies of BPH. The obtained BPH sialotranscripome provides a list of genes that have potential roles in feeding and interaction between BPHs and rice plants.

To elucidate taxonomic eminence of identical pest species is essential for many ecological and conservation studies. Without proficient skills, accurate molecular identification and characterization are laborious and timeconsuming. The coconut leaf beetle, Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), is biologically and morphologically identical to hispid leaf beetle, Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae), and is known as the most harming nuisances of palm cultivation worldwide. The present examination was to establish Wolbachia genotyping analysis along with host cytochrome oxidase subunit I (COI) gene for accurate identification between these individuals of the same family (Chrysomelidae). Here, we have cloned and sequenced a gene coding Wolbachia surface protein (wsp) and COI gene regions amplified from both species by polymerase chain reaction. The nucleotide sequences were directly determined (≈600 bp for wsp and ≈804 bp for COI) and aligned using the multiple alignment algorithms in the ESPript3 package and the MEGA5 program. Comparative sequence analysis indicated that the representative of wsp and COI sequences from these two beetles were highly variable. To ensure this bacterial variation, multilocus sequence typing (MLST) of bacterial genes was conducted, and the results vindicated the same trend of variations. Furthermore, the phylogenetic analysis also indicates that B. longissima and O. nipae being the two different species harbors two distinct Wolbachia Hertig and Burt (Rickettsiales: Anaplamataceae) supergroups B and A, respectively. The present outcomes quickly discriminate between these two species. Considering its simplicity and cost-effectiveness, it can be used as a diagnostic tool for discriminating such invasive species particularly B. longissima and O. nipae which has overlapping morphologic characters.

Hoverflies are potential candidates for biological control of aphid populations; however, identification of closely related hoverfly species by using morphological characteristics is quite difficult. For instance, adults of Sphaerophoria macrogaster (Thomson) (Diptera: Syrphidae)—the predominant species early in the vegetable production season in Japan—are morphologically indistinguishable from those of Sphaerophoria indiana Bigot (Diptera: Syrphidae) without comparison of the male genitalia. Here, we investigated genetic variation of the mitochondrial cytochrome c oxidase subunit I (COI) gene of the two species by DNA sequencing and developed a multiplex PCR method for differentiating the two species. Alignment of COI sequences revealed 1.2% nucleotide variance between the two species. The COI sequence of S. macrogaster collected from Japan was 99.8% identical to those of S. macrogaster collected from India. The COI sequence of S. indiana collected from Japan was 100% identical to that of Sphaerophoria philanthus (Meigen) (Diptera: Syrphidae) collected from Canada. The sizes of the multiplex PCR products differentiated following gel electrophoresis were 162 bp for S. macrogaster and 607 bp for S. macrogaster and S. indiana. The accuracy rate of multiple PCR was 100%. Use of this method will facilitate further research into the characteristics of hoverflies and will improve the efficacy of biological control using hoverflies on vegetable crops.

Pear psyllids are among the most damaging pests in pear orchards, but little knowledge exists of psyllid species in cultivated pear orchards in China. In this study, DNA sequence analyses of the 16S rDNA and cytochrome oxidase I (COI) DNA regions were performed to identify pear psyllids from 28 regions of 20 provinces in China and to classify their genetic relationships to understand the origin of the species. The results showed that Cacopsylla chinensis Yang et Li (Hemiptera: Psyllidae) was found in most pear orchards in China, but Cacopsylla qianli (Hemiptera: Psyllidae) was found in only the cities of Guiyang (Guizhou province) and Xiangyang (Hubei province). The results for the 16S rDNA and COI regions were similar. Based on the nucleotide sequences and phylogenetic analyses of 16S rDNA and COI, C. chinensis could be divided into three groups: lineages I, II, and III. Based on 16S rDNA and COI, lineage II showed approximately 4% and 3% difference from lineage I, and lineage III showed approximately 12% and 9% difference from lineage I, respectively. C. chinensis lineage I was found in most provinces of China, while C. chinensis lineage II samples were mainly found in the Bohai rim region of China, and lineage III samples were found in Northeast China. The results of this study will provide information to pear producers regarding effective control measures to prevent further damage from pear psyllids.

Bactrocera carambolae Drew and Hancock and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) are important pests of many fruits.These flies have been spread across the world through global travel and trade, and new areas are at risk of invasion. Whenever new invasive populations are discovered, quick and accurate identification is needed to mitigate the damage they can cause. Determining invasive pathways can prevent further spread of pests as well as subsequent reinvasions through the same pathway. Molecular markers can be used for both species identification and pathway analysis. We analyzed 1,601 individuals from 19 populations using 765 base pairs of the mitochondrial cytochrome oxidase I (COI) gene to infer the haplotype diversity and population structure within these flies from across their native and invasive ranges. We analyzed these samples by either grouping by species or geographic populations due to the genetic similarity in the mitochondrial genome. We found no genetic structure between B. dorsalis and B. carambolae and our findings suggest recent and most likely ongoing, genetic exchange between these two species in the wild. Hyper-diverse mitochondrial genetic diversity in the native range suggests large population sizes and relatively high mutation rates. Only 52% of the haplotypes found in the trap captures from California are shared with haplotypes from flies found in our global survey, indicating significant genetic diversity in the native range that is missing from our samples. However, these results provide a foundation for the accurate determination of the provenance of invasive populations around the world.

The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of strawberry (Fragaria × ananassa Duch.) grown in greenhouses and outdoors. In this study, we evaluated the resistance status of five common strawberry cultivars (‘Aromas’, ‘Kurdistan’, ‘Missionary’, ‘Paros’, and ‘Queen Elisa’) under laboratory conditions. The developmental times of the preadult and adult stages, total longevity, reproduction, and life table parameters were analyzed according to the age-stage, two-sex life table theory, which provides the most comprehensive description on the survival, stage differentiation, and reproduction of a population. Preadult development was the shortest on Kurdistan and longest on Aromas (17.70 d vs. 21.00 d). The greatest number of oviposition days occurred on Missionary (28.65 d), whereas the fewest were on Queen Elisa (21.58 d). The intrinsic rate of natural increase (r) and finite rate of increase (λ) varied among the cultivars. The highest values were found on Kurdistan (r = 0.1436 d⁻¹, λ=1.1544 d⁻¹), while the lowest values were on the Aromas cultivar (r = 0.1081 d⁻¹, λ=1.1141 d⁻¹). The longest mean generation time (T) of T. urticae occurred on Aromas. Based on the results of the present study, the cultivar Aromas was considered the most resistant to T. urticae and least favored strawberry cultivar for the development and reproduction of the mite. Demographic data of twospotted spider mite on these five strawberry cultivars can be used to improve our understanding of the population dynamics of the pest and thereby develop effective pest management strategies against T. urticae in both integrated and organic strawberry production.

Bactrocera flies are economic pests of agricultural crops all over the world. Among Bactrocera flies, oriental fruit fly is an economically important pest of fruit crops in the world. Basic studies of Bactrocera flies are very important and helpful to the development of integrated management strategies. However, basic studies regarding behavior and age-stage, two-sex life table traits for this pest, which are vital for designing effective control methods, are currently lacking. Considering the importance of B. dorsalis, this study aimed to evaluate the fruit preference and age-stage, two-sex life table traits of B. dorsalis on guava (Psidium guajava), papaya (Carica papaya), and banana (Musa acuminata) fruits in the laboratory. In choice and no-choice tests, the number of visits and oviposition punctures made by female B. dorsalis flies were significantly higher on guava than those on papaya and banana. The life cycle from eggs to male (146.95 ± 3.43 d) and female (164.94 ± 3.85 d) adults was significantly longer on papaya than those on banana and guava. Bactrocera dorsalis females produced significantly more eggs when fed on guava (623.30 eggs female⁻¹) than on papaya (527.80 eggs female⁻¹) or banana (399.60 eggs female⁻¹). Guava was the more suitable fruit for B. dorsalis, and could be used as a bait fruit to manage the B. dorsalis during the fruiting season of papaya and banana.

Host plant resistance may be an effective option to manage soybean aphid, Aphis glycines (Matsumura) (Hemiptera: Aphididae), an important pest on soybean (Glycine max (L.) Merr.) in the U.S. Movement of soybean aphid may be altered by the presence of resistance (i.e., Rag [Resistance to Aphis glycines]) genes in soybean and changes in movement may affect the spatial pattern of a species. This study aims to assess the effects of Rag1 and pyramided Rag1+Rag2 aphid-resistant varieties on movement of soybean aphid under laboratory conditions and to evaluate potential impacts of this movement on spatial pattern of soybean aphid under field conditions. Results from the greenhouse study showed more movement of soybean aphid on both aphid-resistant varieties than the susceptible variety when aphids were placed on unifoliate leaves and no statistically significant difference in movement between Rag1 and pyramided Rag1+Rag2 varieties. When aphids were placed on new growth, movement was greater on pyramided Rag1+Rag2 than the Rag1 and susceptible variety. However, under field conditions, the spatial patterns of soybean aphid in plots with susceptible, Rag1 or pyramided Rag1+Rag2 varieties were aggregated and did not differ among varieties in vegetative and reproductive growth stages. These results are of relevance because they suggest that aspects of soybean aphid management that may be sensitive to changes in spatial pattern of the pest (e.g., natural enemy efficacy and sampling plans) may not be impacted by implementation of varieties with these resistance genes for host plant resistance.

Resistance to phosphine (PH₃) in key insect pests of stored grain is increasing, with a requirement for maintaining a dose as high as 1 mg l^-1 for 14 d for effective fumigation, which is difficult to achieve under most commercial storage conditions. There is no suitable replacement for PH₃, as most of the available alternatives suffer from specific weaknesses, creating an urgent need to increase the efficacy of this fumigant. One such possibility is co-fumigation of PH₃ with another fumigant, sulfuryl fluoride (SO₂F₂—SF), with the goal of decreasing the time required for a successful fumigation. In this study, adult of two PH₃-resistant strains in each of four key grain insect pests, Rhyzopertha dominica, (F.) (Coleoptera: Bostrichidae) Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), and Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) were fumigated with PH₃ and SF individually as well as in combinations at 25°C over 48 h. Mortality responses in each species were subjected to probit analysis to determine the LC₅₀ and LC_99.9 of PH₃, SF, and PH₃ + SF. Co-fumigation of PH₃ with SF resulted in a 50% reduction of the PH₃ concentration required to achieve 99.9% mortality in two pest species. For example, the PH₃ + SF mixture, reduced the amount of PH₃ required from 14.2–14.5 to 5.6–6.36 mg l^-1 and from 2.71–5.03 to 0.93–1.2 mg l^-1, respectively, for C. ferrugineus and S. oryzae.The overall mortality response to the PH₃ + SF mixture followed an “additive model” suggesting that mutual enhancement in toxicity can be achieved with this mixture specifically to control PH₃-resistant insects.

Spent poultry litter use as a fertilizer in horticulture supports stable fly Stomoxys calcitrans (L.) (Diptera: Muscidae) development. Stable fly continues to have an economic impact on livestock production and rural lifestyle in southwestern Australia. The use of raw poultry manure is banned in 12 Shires surrounding Perth. The loss of market options for West Australian broiler growers has caused economic hardship. Hence, this study examined a range of chemical and biological amendments to spent poultry broiler litter in preventing stable fly and nuisance fly development. These included alkalizers (i.e., lime sand, quicklime, soda ash, and shell grit), acidifiers (aluminum sulfate, sodium bisulfate), gypsum, zeolite, spongolite, calcium cyanamide, and two fungal agents. The treated litters were placed under irrigation in horticulture with amendments added prior to them being exposed in the field as replicate 1-liter pads. In total, 19,559 stable flies developed from the spent litters exposed over five field experiments (88.7% of all flies recovered). House flies (Musca domestica L. (Diptera: Muscidae); 2,067 or 9.4%), false stable flies (Muscina stabulans Fallén (Diptera: Muscidae); 414 or 1.9%), and two sarcophagids (flesh fly) also developed from the litter. Borax completely prevented any fly development from the litter. Calcium cyanamide (1–2.5% v/v) and sodium bisulfate (10%) reduced stable fly numbers by as much as 99–100% when added to litter. Alkalizers, zeolite, spongolite, and entomopathogenic fungi had no significant impact on stable fly development. The addition of either calcium cyanamide or sodium bisulfate to raw litter can boost the fertilizer value of the litter while preventing stable fly development.

This study was carried out to assess the impact of pollen feeding from common floral sources in Thailand (e.g., tea, coffee, and bitter bush) on royal jelly (RJ) properties (i.e., protein pattern, (E)-9-hydroxydec-2-enoic acid (9-HDA), and (E)-10-hydroxy-2-decenoic acid (10-HDA) contents and antibacterial activity). The protein patterns from three different pollen were different, while RJ samples derived from bee colonies fed by different pollen, exhibited similar protein patterns. RJ samples from bee colonies fed by pollen from bitter bush and coffee possessed the higher 10-HDA levels than RJ collected from bee colonies fed by tea pollen. The 9-HDA was found in lower amount than 10-HDA in every sample. Even though the antibacterial activities of pollen were varied, however, RJ samples exhibited similar antibacterial properties. This is the first report showing that different pollen feeding affected 10-HDA contents, but not affected overall protein content and antibacterial properties.

High-value trees, such as those growing in residential, recreational, or administrative sites, are often susceptible to colonization by bark beetles (Coleoptera: Curculionidae: Scolytinae) as a result of increased amounts of stress associated with off-site plantings, drought, soil compaction, and/or mechanical injury.The value of these trees, cost of removing dead trees, and loss of aesthetics often justify the use of insecticides to protect trees from mortality attributed to bark beetles. Carbaryl (1-naphthyl methylcarbamate) is among the most effective, economically-viable, and ecologically-compatible insecticides available for protecting conifers from several species of bark beetles in the western United States. Treatments are usually applied in spring prior to initiation of flight of the target species. We evaluated the efficacy of spring and fall applications of carbaryl for protecting individual ponderosa pine, Pinus ponderosa Dougl. ex Laws. (Pinales: Pinaceae), from mortality attributed to mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), in Idaho. Both spring and fall treatments of 2.0% a.i. carbaryl (maximum label rate; Sevin SL, Bayer Environmental Science, Montvale, NJ 07645) provided one field season of protection, and thus should be applied annually if tree protection is desired for multiple years. Our research also provides some insight on the efficacy of carbaryl treatments after wildfire. We found no evidence that a mixed-severity wildfire negatively affected the efficacy of carbaryl treatments.

For the first time, the repellent and insecticidal effects of eucalypt essential oil (Eucalyptus globulus) in its free form and associated with different nanostructures (nanoemulsion and nanocapsules) were investigated against Musca domestica (Diptera: Muscidae) and Haemotobia irritans (Diptera: Muscidae) flies. Specimens of M. domestica were collected, separated into groups (n = 10), treated with aspersion of essential oil of eucalypt in its free (1, 5, and 10%) and nanostructured (nanoemulsion or nanoencapsulated at 1, 3, and 5%, respectively) forms.The determination of the insecticidal effect was performed by counting the number of dead flies at intervals of 30, 60, 120, 360 and 750 min after oil aspersion. E. globulus essential oil showed insecticidal effect against M. domestica at concentrations of 1 and 5%. Eucalypt essential oil (10%) caused 100% mortality of M. domestica after 750 min of the treatment. Nanocapsules (3 and 5%) showed efficacy by reducing the number of flies. On the other hand, nanoemulsion did not show insecticidal effect. The repellent action of E. globulus concentrations of 5% was tested against H. irritans on naturally infested cows.The repellent action against H. irritans was verified soon after pulverization. After 24 h, a significant reduction on horn flies' population (83.33 and 66.66%) was observed using free and nanoencapsulated forms tested, respectively. E. globulus essential oil demonstrated insecticidal and repellent effects against M. domestica and H. irritans flies.

The striped cucumber beetle, Acalymma vittatum (F.) (Coleoptera: Chrysomelidae), is a key pest of cucurbits in eastern North America, rapidly colonizing young plantings and vectoring bacterial wilt of cucurbits. Its aggregation pheromone has been identified and synthesized stereospecifically, but has not been field tested to date. Here, we present field bioassays of this pheromone, using mixed vittatalactone made with a novel and cost-efficient semispecific synthesis. This mixture of eight stereoisomers of (2R,3R)-vittatalactone proved highly attractive to both sexes of striped cucumber beetle, using two different trap types and a pilot attract-and-kill combination with watermelon containing the diabroticine feeding stimulant cucurbitacin-E-glycoside, under field conditions in cucurbit vegetable plantings. Availability of mixed vittatalactones could enable highly effective and specific management of striped cucumber beetle.

House flies, Musca domestica L. (Diptera: Muscidae), are major pests at animal production facilities. Insecticides, particularly pyrethroids, have been used for control of house fly populations for more than 30 yr, but the evolution of resistance will likely jeopardize fly control efforts. A major mechanism of pyrethroid resistance in the house fly is target site insensitivity (due to mutations in the Voltage-sensitive sodium channel [Vssc]). Based on a survey of house fly populations in 2007 and 2008, the most common resistance allele at 2/3 of the states in the United States is kdr-his. This was unexpected given the relatively lower level of resistance this allele confers, and led to speculation that the kdr-his allele may have a minimal fitness cost in the absence of insecticide. The goal of this study was to evaluate the fitness cost of kdr-his by monitoring the changes in allele frequency over 15 generations in the absence of insecticide. In crosses with two different insecticide susceptible strains, we found that kdr-his had a significant fitness cost. The implications of these results to insecticide resistance monitoring and management are discussed.