Clostera anastomosis L. (Lepidoptera: Notodontidae) is a serious defoliator of poplar, Populus spp., trees in China. To establish a baseline of information for possible ecological management of this pest, we studied its emergence, courtship, mating, and oviposition behaviors in the laboratory at 27 ± 1°C and 60 ± 10% relative humidity under a 14:10-h (light:dark) photoperiod. Under these conditions, peak emergence of female adults occurred in the sixth day after pupation, and peak emergence of males was in the seventh day after pupation. Emergence for both sexes occurred throughout the day. Courtship behavior began at the sixth hour of scotophase, reaching peak activity between the 10th hour of scotophase and the first hour of photophase. The courtship and mating success rate were highest for 1-d-old females, and then gradually decreased with age until no mating was observed after females were 4 d old. With 1-d-old females, mating was only observed from the seventh hour of scotophase to the first hour of photophase, with peak activity at 0.5 h after the onset of photophase. Oviposition primarily occurred within 3 d after mating, with 49.8% of the eggs being deposited during the first day after mating. These results demonstrate that there are distinct circadian rhythms in adult emergence and subsequent reproductive behavior of C. anastomosis, thus providing a basis for development of monitoring and management strategies of this pest.

An eco-friendly electron beam irradiation (EBI) technology was used to assess the effect of EBI on the different development stages of Callosobruchus maculatus (F.) and Bactrocera zonata (Saunders). No adults emerged after 3-d-old eggs of C. maculatus were irradiated with 304.8 Gy of EBI, and no adults emerged from the F₁ generation of larvae and pupae irradiated with 103.6 Gy. The adult stage of C. maculatus was the most tolerant of EBI, with a high dose (414.3 Gy) irradiation of the adult stage resulting in complete prevention of the F₁ generation adult emergence. Large-scale tests confirmed that 414.3 Gy was an effective dose for the phytosanitary and security treatment for C. maculatus. An EBI dose of 414.3 Gy prevented B. zonata egg hatching. EBI doses of 304.8, 414.3, and 653.5 Gy prevented the development of first, second, and third larval instars to pupation, respectively. Using the criterion of adult emergence from the F₁ generation, targeting the third larval stage, considered the most tolerant stage to EBI, a dose of 304.8 Gy was effective for quarantine and security treatment of B. zonata.

The leaf disc method is widely used in laboratory studies of the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). We examined the effects of the orientation of the leaf discs (upright, inverted, and horizontally perpendicular to the surface) on the biological parameters of aphids from three populations (i.e., Gansu red, Gansu green, and Yunnan green) of A. pisum. We found that aphids feeding on inverted or horizontally perpendicular positioned leaf discs exhibited higher survival and fecundity rates than those aphids feeding on upright positioned leaf discs for all three populations. Overall, aphids in both the Gansu red and Gansu green populations performed best when feeding on the inverted leaf discs, whereas aphids of the Yunnan green population performed best in the horizontally perpendicular orientation. We postulate this may be related to body temperature adjustment by the aphids through adjusting the orientation angle between its body and the sun. Our results provide a theoretical basis for optimizing the rearing parameters of the pea aphid, reducing the systematic error of experiments, and facilitating the acquisition of more reliable data under laboratory conditions.

The Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is a major pest of Hong Yang kiwifruit (Actinidia chinensis Planch cv. chinensis) grown in China. Our transcriptome analysis of the interaction between Hong Yang kiwifruit and B. dorsalis revealed numerous changes in gene expression level attributable to Oriental fruit fly feeding, resulting in the down-regulation of 112 genes and the up-regulation of 226 genes. Gene ontology analysis revealed that differential expression genes (DEGs) were mainly involved in biological processes (4,568; 56.28%), molecular function (2,297; 28.30%), and cellular components (1,251; 15.41%). By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG), 258 DEGs were assigned to 51 KEGG pathways belonging to five main categories: metabolism (239, 92.64%), genetic information processing (10, 3.88%), organismal systems (5, 1.94%), cellular processes (3, 1.16%), and environmental information processing (1, 0.39%). The numbers of DEGs up-regulated were much higher than those down-regulated. Expression of genes involved in the secondary metabolism was detected, and several key genes showed differential expression. Our results suggest that B. dorsalis induced defense response of Hong Yang kiwifruit, including hypersensitive response and immunity triggered by either pathogen/microbe-associated molecular patterns or immunity effectors. Metabolic process was also adjusted to adapt to these responses. Our results provide extensive transcriptome information for A. chinensis and valuable clues for elucidating the mechanism of interaction between Hong Yang kiwifruit and B. dorsalis, and will facilitate molecular breeding for Actinidia crop plants.

Tetranychus urticae (Koch) (Trombidiformes: Tetranychidae) is a cosmopolitan spider mite species that infests more than 900 species of plants, including commercial species. Tetranychus cinnabarinus (Boudreaux) is characterized by a red coloration, in contrast to the green-colored T. urticae. Both are occasionally found coexisting in warm environments, and, for that reason, they are considered by some to be synonyms. In this study, we identified specimens of the two morphospecies using optical and electron microscopy and amplification of a segment of the mitochondrial cytochrome oxidase I (COI) gene. Bioassays determined the level of susceptibility and survival of both morphospecies when they were infected with the entomopathogenic fungus Neozygites floridana (Weiser and Muma). For the evaluation of the susceptibility of these morphospecies to N. floridana, bioassays were conducted under conditions of 25 ± 2°C, 60 ± 5% relative humidity, and a 12:12-h photoperiod regime. From these bioassays, we found that T. cinnabarinus was less susceptible to N. floridana and that there is a higher level of fertility, survival, and development in the T. cinnabarinus than in the T. urticae mites. Within a mass rearing system, T. cinnabarinus appears be a more efficaceous functional food for predatory mites, such as Phytoseiulus persimilis (Athias-Henriot) (Mesostigmata: Phytoseiidae), than T. urticae to support rearing and release of biological agents for integrated pest management.

Spotted-wing drosophila, Drosophila suzukii (Matsumura), is a significant, global invasive species first confirmed in the United States in 2008. Since the first detection in Minnesota in 2012, D. suzukii rapidly became a major economic pest of berry crops in the state. Effective monitoring of adult D. suzukii populations is a crucial aspect of developing integrated pest management (IPM) programs for at-risk crops. Drosophila suzukii monitoring research was conducted in 2016 and 2017 to better understand the effectiveness of two commercially available trapping systems for early detection of adults in spring and how mean trap catches compared over time. In addition, using the Scentry trap, we assessed the impact of lure age on trap performance. Finally, a study was conducted to better understand the diurnal activity pattern for adult D. suzukii under Minnesota summer conditions. Results comparing the trapping systems indicated each system varied in its ability to detect first catch of D. suzukii but that both commercial traps/lures were effective. The lure age study showed that lures can be changed less frequently than initially suggested. Temporal activity studies, as measured by trap catch via Scentry traps, indicated that adult D. suzukii demonstrated a crepuscular activity pattern in raspberry and blueberry. The results of these studies should benefit growers as they continue to fine-tune fruit IPM programs for D. suzukii.

Aphis gossypii Glover and Acyrthosiphon gossypii Mordvilko (Hemiptera: Aphididae) are important pests of cotton (Gossypium hirsutum L.) in Xinjiang, China, that reduce yield and lint quality. We studied competition between the two aphid species in laboratory arenas to better understand population change and competitive advantage between the two and to provide a theoretical basis for the observed population outbreak of aphids in cotton fields. To study intraspecific competition, densities of 5, 10, and 15 aphids per 5-cm-diameter leaf disc were established in individual 6-cm-diameter arenas. Equal numbers of each species were placed on leaf discs in the arenas to establish densities of 3, 5, and 10 aphids of each species per leaf disc to assess interspecific competition. In intraspecific competition assays, the mean generation time (T) and the net reproductive rate (R_o) of both species decreased as aphid density increased, while the intrinsic rate of increase (r) and finite rate of increase (λ) of Acy. gossypii increased as density increased. In interspecific competition assays, population growth of A. gossypii was higher than with Acy. gossypii at the same density, while the mean generation time of A. gossypii was less than with Acy. gossypii. The net reproductive rate, intrinsic rate of increase, and finite rate of increase were higher in A. gossypii than in Acy. gossypii. Density is a key factor affecting competition between A. gossypii and Acy. gossypii. The higher the density, the more intense the interspecific competition, with interspecific competitiveness of A. gossypii stronger than that of Acy. gossypii.

The mirid, Lygus pratensis (L.) (Hemiptera: Miridae), is a major pest of cotton (Gossypium spp.) in Xinjiang Uyghur Autonomous Region, China. In this study, we aimed to reveal the preferences of L. pratensis toward four potential trap crop plants for use in controlling this pest. The population densities of L. pratensis on five host plants were investigated by visual observation, and the behavioral responses of L. pratensis to the five host plants were determined by Y-type olfactory assays and laboratory selectivity assays. The results showed significant differences in host preferences in the field. The average numbers of adults on the five host plants are in the following order, from high to low: Lepidium latifolium (L.), Kochia prostrata (L.) Schrad, Chenopodium glaucum (L.), Medicago sativa (L.), and Gossypium spp. Laboratory selectivity assays found that K. prostrata had the highest number of adults at 5 min, but L. latifolium had the highest number of adults from 1.5 to 4.5 h. The Y-tube olfactometer assays found no significant evidence for selection of L. pratensis between the volatiles of M. sativa and pure air, but did for the other four plants. In conclusion, the blooming stage of L. latifolium was the most attractive to L. pratensis in the field and is, thus, a potential trap crop plant for L. pratensis.

Fumigant activity of the essential oil extracted from Tridax procumbens L. (Asterales: Asteraceae) by water distillation was assessed against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), together with its effect on the germination of three Thai varieties of rice, Oryza sativa L. (Poales: Poaceae). Tridax procumbens essential oil contains 25 compounds with five principal components as 1,2-cyclooctanediol (11.49%), hexanal (5.34%), 4-heptenal (4.92%), 2,4-nonadienal (3.10%), and 1,6-dimethylhepta-1,3,5-triene (1.67%). Tridax procumbens essential oil was a fumigant toxin to S. zeamais adults with a median lethal concentration (LC₅₀) of 1,509.79 µl/L air 24 h after exposure. The highest concentration of 250 µl/L air of T. procumbens essential oil showed low efficacy in killing adults of S. zeamais at 24 h with 10% mortality. This concentration also affected newly emerged progeny (F1) of S. zeamais compared to the control, with the highest reduction of 92.87%, and also decreased seed germination of the three varieties of Thai rice RD6, Kham Na Sinuan, and KDML at 94.25, 96.0, and 93.25%, respectively, compared with the control (98.0–98.75%). Results indicate that essential oil from T. procumbens has potential for application on stored products to control progeny of S. zeamais that cause seed damage.

The innate immune response in insects relies on cellular responses. In most lepidopteran species, challenging the immune system causes an increase in hemocyte numbers and promotes encapsulation and melanization of invading objects, such as parasitoid eggs or artificial objects (e.g., nylon implants). We studied the effects of carbon particles (Sumi ink) on the immune response of Galleria mellonella L. (Lepidoptera: Pyralidae) last-instar larvae. Ink injections increased total hemocyte counts in a dose-dependent manner, with the 40 and 80% concentrations being most effective in eliciting hemocyte response. Hemocyte numbers increased significantly at 4 and 6 h after ink injection. Lemongrass essential oil (0.18, 0.36, and 0.72 µg/larva) and citral (0.12, 0.24, and 0.48 µg/larva) reversed the mobilization of hemocytes by the ink. Melanization of nylon larvae implants started as early as 15 min after implant insertion and reached maximum observed levels within 1 h. The degree of melanization also was higher in larvae challenged with ink 1 h prior to implant removal, which suggests initialization of the immune response. Citral injections inhibited implant melanization both in unchallenged and ink-challenged larvae. In the former case, citral concentrations needed for effective inhibition were less (0.3 µg/larva) than in ink-challenged larvae (1.2 and 2.4 µg/larva).

Changes to the community of symbiotic bacteria and fungi in the brown planthopper, Nilaparvata lugens Stål, were measured at different times after exposure to conidial suspensions of Metarhizium flavoviride Gams and Roszypal. Over all concentrations tested, bacterial species associated with N. lugens comprised 8 phyla, 17 classes, 22 orders, 26 families, and 31 genera of which the relative proportions of Arsenophonus, Burkholderia, Enterobacter, Pseudomonas, Stenotrophomonas, and Bacteroides were highest. The relative abundance and diversity of bacteria were highest in the carrier control (0.05% Tween-80 only). Fungi comprised 1 phyla, 5 classes, 10 orders, 13 families, and 18 genera, with Metarhizium being the dominant taxon in specimens from all treatment groups. Metarhizium spp. was greatest in the concentrations of 10⁷ and 10⁸ conidia/ml at 72 hours after exposure, reaching 94.82% and 93.74% of taxonomic units, respectively. We deduced that M. flavoviride competes for nutrition with midgut microorganisms; therefore, exposure to a pathogenic fungus will change the abundance and diversity of bacterial and fungal microorganisms in the midguts of hosts, and pathogens will impact the structure of bacterial communities in the host midgut with an alteration in the bacterial species composition. We observed that following the exposure of N. lugens to M. flavoviride, Metarhizium spp. dominated in the midgut of the host, the abundance and diversity of midgut fungal microorganisms decreased, and the dominant bacterial species in the midgut shifted.

A generic trap lure blend of host volatiles (ethanol + α-pinene) and Ips bark beetle pheromones (ipsenol + ipsdienol) is effective for detecting numerous species of longhorn beetles (Coleoptera: Cerambycidae) in pine forests of North America. In 2021, the potential benefits of adding two other Ips pheromones (lanierone and cis-verbenol) to traps baited with the pine beetle lure blend were determined in north Georgia. Lanierone and cis-verbenol had no effect on catches of the six cerambycid species captured in the study: Acanthocinus nodosus (F.), A. obsoletus (LeConte), Astylopsis arcuata (LeConte), Monochamus titillator (F.), Neoclytus acuminatus (F.), and Xylotrechus sagittatus Germar. Similarly, neither compound had any effect on catches of some common ambrosia and bark beetles and snout weevils nor on catches of some associated predators, all commonly caught in traps baited with the pine beetle lure blend. In contrast, catches of Ips avulsus Eichhoff and I. grandicollis (Eichhoff) were enhanced by the addition of lanierone, whereas those of I. calligraphus (Germar) and Hylastes tenuis Eichhoff (Curculionidae) were enhanced by the addition of cis-verbenol. The data do not support the addition of lanierone or cis-verbenol to the blend of ethanol + α-pinene + ipsenol + ipsdienol as a trap lure blend for the broad detection of pine longhorn beetles in north Georgia.

The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is a worldwide invasive pest of tomatoes (Solanum lycopersicum L.) that reached West Africa in 2010. Synthetic insecticides remain the most widely used method of control, but several biological alternatives are being developed. In this work, we evaluated nine biopesticides available on the West African market for their ability to control T. absoluta. Using standard leaf or egg dip bioassay methodology, we compared both the ovicidal and the larvicidal activity of these biopesticides at various concentrations of active ingredients. We found that, for each biopesticide tested, the larval lethal concentrations (LC) (8.2–41.14 ml/L) to be lower than those necessary to stop egg hatching (26.7–409.7 ml/L). Two products (Bangr-Kièta [BK]; Bangr-Pougo [BP], formulated in powder), both based on Azadirachta indica A. Jussieu fruit and leaf extracts and Khaya senegalensis (Desrousseaux) A. Jussieu bark extract, showed high efficacy in reducing egg hatchability at their recommended doses, with a calculated control failure likelihood (CFL) reaching 0%. These two products, together with a third one (BP) based on Mitracarpus scaber Zuccarini and K. senegalensis extracts, also showed the strongest larvicidal effects (CFL = 0%). All other tested biological insecticides showed significant efficiency but were found to be less effective at their recommended doses. Because the leafminer has developed resistance to most of the synthetic insecticide available on the market, we recommend that West African tomato producers are encouraged to use the most efficient biological products available.