Diapause, an important developmental process in insects, is a physiological adaptation for avoiding adverse environmental conditions. Laodelphax striatellus Fallén is an important graminaceous crop pest in East Asia, and there are few reports regarding the nymphal diapause from fields with rice–wheat rotation. In the present study, we determined the fourth-instar nymph as the main diapause stage through investigation under field and laboratory conditions. Developmental duration of the third and fourth instars was longer during the short day-length (10 h light:14 h dark [10L:14D]) at 20°C than during other photoperiods. The third-instar nymph is the most sensitive stage to changes in the photoperiod. The optimal environmental factor for diapause termination was long day-length (16L:8D) at 25 to 28°C. The supercooling point was significantly reduced in diapause nymphs, and activities of trehalase, pyruvate kinase, and sorbitol dehydrogenase were significantly decreased (46.46, 37.90, and 17.64%, respectively). The information obtained in this study may be beneficial to the development of control strategies for this pest.

Ulomoides dermestoides (Chevrolat) (Coleoptera, Tenebrionidae) is a storage pest and an insect of medical importance. Since this insect lives in the dark and does not emit sounds, its sensation of the external environment is based primarily on sensilla, so it could serve as an ideal model for the study of these structures. Scanning electron microscopy was used to identify the types of antennal sensilla of male and female U. dermestoides and to characterize the function of different types of sensilla observed. The bead-like antenna of U. dermestoides is composed of a scape (one segment), a pedicel (one segment), and a flagellum (nine segments). Six types of sensilla were observed on the antennae of both females and males: the sensilla trichoidea (subtypes I, II, and III), sensilla chaetica (subtypes I, II, and III), sensilla basiconica, basiconic mastoid sensillum, sensilla styloconica (subtypes I and II), and the Böhm bristle. The Student's t test was used to compare the distribution of these sensilla.

The weevil Rhinocyllus conicus Froelich was introduced in Georgia, USA as a biological control agent of musk thistle, Carduus nutans L. (Asteraceae) in 1991. Musk thistle populations and R. conicus infestations were monitored over 10 yr at four sites in central Georgia. Musk thistle populations declined substantially as R. conicus populations increased at all sites, but thistle infestations remained problematic at some sites. A laboratory cage study found that R. conicus would lay eggs on flower buds of yellow thistle, Cirsium horridulum Michaux, bull thistle Cirsium vulgare (Savi) Tenore, and blessed milkthistle, Silybum marianum (L.) Gaertner in no-choice and choice tests with and without Ca. nutans. Carduus nutans was preferred over the other thistle species, but the other thistle species were acceptable for oviposition by R. conicus. One or more mixed field infestations of musk thistle and yellow, bull, or blessed milkthistles were sampled for R. conicus infestation. Rhinocyllus conicus was not recovered from capitula of C. vulgare or S. marianum, but R. conicus was found infesting capitula of the native nontarget thistle C. horridulum at multiple field sites from 1997 to 2001. At four sites in 2000 and 2001, R. conicus infestations in C. horridulum averaged 7.47% and 31.19% of flowerheads sampled. This is the first report of R. conicus attacking the nontarget thistle C. horridulum in the field, but the impact that R. conicus may have on C. horridulum populations is not known.

Cowpea curculio, Chalcodermus aeneus (Boheman), is the major pest of southern peas or cowpea, Vigna unguiculata (L.). Throughout the southeastern United States, current management recommendations for cowpea curculio rely on insecticide applications; however, resistance has been observed. Entomopathogenic biocontrol agents, specifically nematodes in the genera Steinernema and Heterorhabditis and fungi in the genera Beauveria and Metarhizium, have shown efficacy with other curculio pests. We conducted laboratory bioassays to assess the virulence of entomopathogenic agents as a first step to provide alternative control strategies against cowpea curculio. Using controlled environmental conditions, we tested the effects of nematodes (Steinernema carpocapsae Weiser, Steinernema feltiae Filipjev, Heterorhabditis bacteriophora Poinar, and Heterorhabditis indica Poinar) and two fungi (Beauveria bassiana Balsamo and Metarhizium brunneum Petch) on survival and infectivity of cowpea curculio. Heterorhabditis indica had the greatest effect on cowpea curculio larvae, resulting in less than 20% survival and greater than a 65% infection rate. Conversely, cowpea curculio larvae exposed to fungal pathogens had similar survival to larvae exposed to water and less than 20% infection rates. For fungal pathogens, applying the pathogen to the soil surface prior to introduction of cowpea curculio larvae led to infection of the larvae. Our results suggest nematodes and fungal pathogens are capable of infecting cowpea curculio. Our data provide the basis for further tests examining the timing and application rates in field situations.

Functional response and mutual interference of Cotesia vestalis (Haliday) was studied on second-instar diamondback moth, Plutella xylostella (L.), larvae. The parasitoid exhibited Type II functional response to its host with attack rates of 0.045 (Holling disc equation) and 0.122 (Rogers random equation) and a handling time of 0.85 h (Holling disc equation) and 1.18 h (Rogers random equation). Theoretical maximum number of hosts that could be parasitized over a period of 24 h by the parasitoid was estimated to be 28.8 (Holling equation) and 20.3 (Rogers equation). Per capita number of parasitization decreased significantly from 12.4 to 3.8 with the increase in the parasitoid density from 2 to 8, indicating that mutual interference occurs when two or more numbers of parasitoid females forage in the same arena. The relationship between searching efficiency (E) and density (P) of the parasitoid was log E = –0.205 0.769 log P, with a mutual interference coefficient of 0.77.

Laboratory studies of the numerical response of the predator Cyrtorhinus lividipennis Reuter to its natural prey, Nilaparvata lugens Stal, determined the reproductive response to number of eggs oviposited, prey-dependent birth rate, prey-dependent mortality rate, and life cycle duration to different densities of N. lugens eggs. The experiments were conducted in cages with 1, 5, 10, 15, 20, and 30 eggs/predator per cage with 20 replications. The results indicated that the numerical response of C. lividipennis was positively related to prey density, with greater amounts of eggs laid, a longer duration of the lifespan, and adult age observed at a high prey density than a low prey density. However, the sex ratio and adult longevity were not affected by the prey density. The minimum prey density for completing C. lividipennis development was 5 eggs/d, whereas the minimum number of prey needed to produce an egg was 10 eggs/d. The study of the numerical response provided data for calculating the prey-dependent birth rate and prey-dependent mortality rate when C. lividipennis consumed one N. lugens egg. The results indicated that the prey-density–dependent birth rate was 0.123 eggs/bug/d and the prey-density–dependent mortality rate was 0.027 bugs/d.

The small southern pine engraver, Ips avulsus Eichhoff (Coleoptera: Scolytidae), is one member of a guild of southern pine bark beetles that causes millions of dollars of losses to southern U.S. pine forests annually. Our objective was to determine the impact of a commercial preparation of the entomopathogenic fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Ascomycota: Hypocreales) in protecting pine host plant tissue from colonization and damage by I. avulsus and on the B. bassiana–induced mortality of I. avulsus adults during the first 2 wk of host attack. The field trials were conducted in the Kisatchie National Forest (Rapides Parish, LA) using a small-bolt technique. Results showed that the I. avulsus adults successfully colonized both the B. bassiana–treated bolts and the control bolts within the first week of field exposure. Although the formulation did not protect bolts from attack, it caused significantly higher mortality of I. avulsus adults in B. bassiana–treated bolts than in the control, and significantly reduced the number of adults that reemerged. Approximately 84% of I. avulsus adults found in the B. bassiana–treated bolts died from B. bassiana infection and never reemerged, compared to 14% in the control bolts. Although effects from B. bassiana were too late to stop I. avulsus from entering host bolts, the high rates of beetle mortality observed under the bark suggest potential utility of the formulation for managing pine bark beetles. Successful application strategies and tactics are unknown at this point and will depend on many factors, including deployment techniques.

Laboratory assays of the toxicity of seven vegetable seed oils (artichoke, bitter melon, castor, flaxseed, mustard, peach kernel, and rosehip) to eggs and nymphs of the pear psylla, Cacopsylla pyricola (Foerster), were conducted as well as the oviposition-deterrent potential of the oils to female winterform and summerform morphotypes. Despite low to moderate toxicity to the eggs, the oils caused high levels of nymph mortality (up to 99%) with mortality levels depending on the type of oils and the concentrations tested. Exposure to flaxseed, mustard, artichoke, and bitter melon oils resulted in the highest nymphal mortality. Overall, the deterrence of oviposition by the oils was higher against winterform females than summerform females. In choice tests, all oils except flaxseed oil at 1% and rosehip oil at 1%, 1.5%, and 2% deterred oviposition by winterform females. Female summerform oviposition was deterred in choice tests by peach kernel oil at 1% and mustard oil and bitter melon oil at 2%. In no-choice tests, significantly fewer eggs were produced by winterform females following treatment with mustard, bitter melon, artichoke, and flaxseed oils, and over 83% deterrence of summerform oviposition was observed in flaxseed and mustard oil treatments. Severe phytotoxic effects were observed with only a high concentration (2%) of artichoke and bitter melon oils. Based on these results, mustard, flaxseed, bitter melon, and artichoke oils appear to be candidates for development of control agents against eggs and nymphs of the winterform morphotype C. pyricola.

Climate models predict that the atmospheric CO₂ concentration will double and atmospheric temperatures will increase 1.8–4.0°C globally by the end of this century. These changes will influence the growth of both crop plants and herbivores. The effects of elevated CO₂ and temperature on the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), feeding on maize, Zea mays L., were examined in environmentally controlled chambers. Elevated CO₂ decreased N content and increased total nonstructural carbohydrate (TNC) content and the TNC:N ratio in maize leaves. Developmental time of larvae, protonymphs, deutonymphs, and the entire immature development of T. urticae was reduced at elevated temperatures, while elevated CO₂ slightly mitigated the effects of elevated temperature on developmental time. The fecundity of T. urticae declined under elevated CO₂ and temperature. Tetranychus urticae had lower net reproductive rate and shorter generation time at elevated temperatures, regardless of CO₂ level. These results indicate that elevated CO₂-mediated decrease in nutritional quality of maize leaves extends the development time of T. urticae. Taken together, with the increase of CO₂ and temperature, the growth and development was accelerated for T. urticae feeding on maize, but its fecundity declined, which will decrease the T. urticae damage to maize for each generation. However, the number of generations will increase in high accumulative temperature regions, which may exacerbate T. urticae damage to maize. Thus, more integrated studies and realistic experimental designs are needed to predict the maize–T. urticae interaction under future climate change scenarios.

A comparative study of termite (Isoptera: Termitidae) species diversity and richness in three ecologically different habitats was conducted in the Shivamogga District of Karnataka, India, from September 2014 to August 2015. A standard belt transect method was used to sample the termites in each habitat for the duration of the study. The three habitats studied were rainforest, semimalnad represented by degraded forest area that was previously rainforest, and maidan represented by open field and plantation crops with no tree cover. Twenty-two species were collected, all representing the family Termitidae. Nine species were recorded from the maidan habitat, 14 species from the semimalnad habitat, and 18 species from a rainforest habitat. Of the 18 species recorded from the rainforest, 6 were exclusively recorded there and not in the maidan or the semimalnad habitats. Species richness, as indicated by Shannon's diversity index (H), was highest in the rainforest (1.62), followed by the semimalnad (1.43) and maidan (1.13) habitats. The variation in diversity across these three habitats is attributed to anthropogenic disturbance, cropping patterns, topography, and bioclimatic factors. Implications of habitat disturbance on termite diversity are discussed.

The sugarcane aphid Melanaphis sacchari (Zehntner) was discovered infesting grain sorghum close to Beaumont, TX, near the Texas and Louisiana state line a few kilometers inland from the Gulf Coast in the late summer of 2013, and has been a perennial pest of grain, forage, and sweet sorghums. Our research was aimed at identifying sorghum germplasm that expresses host-plant resistance to the sugarcane aphid. We originally screened 36 lines including two known resistant sorghums (Tx2783 and DKS-37-07) and two known susceptible sources (WSH 117 and MORCH 858). From this screen, two pollinator lines (R.11143 and R.11259) developed by the USDA-ARS in Lubbock, TX, exhibited tolerance as indicated by damage ratings and growth characteristics, such as plant height, number of leaves, and chlorophyll content. Line R.11143 had a slight net gain in chlorophyll content in the infested plants compared to the noninfested plants, indicating a highly tolerant sorghum. The R.11143 and R.11259 lines also expressed significant levels of antibiosis where net reproduction, number of nymphs produced in a day, intrinsic rate of increase, and the reproductive period in days were all significantly lower than all entries, with the exception of the known resistant controls DKS 37-07 and RTx2783. Pollinators R.11143 and R.11259 are recommended to be used in breeding programs for developing resistant sorghums threatened by the sugarcane aphid.

The corn wireworm, Melanotus communis (Gyllenhal), is the most important wireworm pest of sugarcane (Saccharum spp. hybrid) production in Florida. The feeding behavior of wireworms (larvae) at soil temperatures from 18 to 28°C characteristic of Florida sugarcane was determined in laboratory tests. In blind tests, we showed that small, smooth-skinned Baby Yukon Gold potatoes, Solanum tuberosum L., could be used to successfully detect even minor feeding by the wireworms. This technique may prove useful to other wireworm researchers. Feeding frequency and percentage of wireworms feeding increased with increasing soil temperatures. Similarly, there was a positive correlation of weight gain with soil temperature. Our data showed that, although slowing down in the winter, some feeding damage by the wireworms is expected throughout the year in Florida sugarcane. Lastly, we observed very high variability in wireworm feeding and weight change even under constant conditions. Overall, our experience in this study is consistent with the general theme that wireworm feeding and weight change are highly variable even under constant conditions.

Numbers of bumblebees (Hymenoptera: Apidae) are decreasing in many European countries. Thirty-six species native to Poland are legally protected, and 19 are considered as threatened with extinction. A method for assessing the attractiveness of garden flowering plants for bumblebees was developed in this study. Observations were conducted through the growing seasons in 2011 and 2012 in two botanical gardens located in Wrocław city, Poland. Bumblebees were observed and recorded on flowers during 30-min observations and determined to species level. An algorithm was used to define the attractiveness (At_p) of visited flowers, including the frequency of flower visits by bumblebees during phenological seasons. The resulting At_p values were assigned to a 4-level scale of attractiveness. In the botanical garden, the most “valuable” plant species were: Rhododendron catawbiense Michaux, Lathyrus vernus Bentham, Lathyrus odoratus L., Aristolochia clematitis L., Cyanus montanus Hill, Aconitum lycoctonum L., Hosta sp., Spiraea japonica L. filius, Lavandula × intermedia Loiseleur-Deslongchamps, and Lavandula angustifolia Miller; and in the Medicinal Plants Botanical Garden there were: Geranium phaeum L., Agastache rugosa Kuntze, Glycyrrhiza glabra L., Cydonia oblonga Miller, R. catawbiense, Monarda didyma L., Aruncus dioicus Fernald, Lavandula angustifolia, Phacelia tanacetifolia Bentham, Origanum vulgare L., and Scutellaria baicalensis Georgi. The proposed algorithm may be useful in protecting bumblebees, which takes into account their nutritional needs or feeding behavior. Careful plant selection in planning green urban areas with high rates of At_p will likely to contribute to an increase in numbers of bumblebees.

In the fall of 2011, we examined the effects of inter–trap distances of 2, 6, and 12 m on catches of bark and wood-boring beetles (and associates) in traps baited with either ethanol α-pinene (EA) or ipsenol ipsdienol (SD) in a stand of loblolly pine, Pinus taeda L., in northern Georgia. Traps baited with EA interrupted catches of Ips avulsus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae) in traps baited with SD at a distance of 2 m but not at distances of 6 or 12 m. In contrast, catches of I. avulsus and Dendroctonus terebrans (Olivier) in traps with EA were greatest in those traps spaced 2 m from the traps baited with SD and lowest at an inter–trap distance of 12 m. Similarly, catches of Monochamus titillator (F.) (Cerambycidae) in traps baited with EA were increased when spaced 2 m from traps baited with SD but not at a spacing of 6 or 12 m. The mean (± SE) diversity of species in traps baited with EA was 19.1 ± 0.5 species/trap and unaffected by distance to traps baited with SD. In contrast, the mean (± SE) species diversity in SD traps was higher in traps 2 m from EA traps (12.8 ± 0.8 species/trap) and lowest in traps 12 m EA traps (8.8 ± 0.5 species/trap). More studies are needed to elucidate the interactions between volatiles emitted from different traps on responses by flying beetles.