As the risks arising from the use of chemical pesticides increase, researchers are continuously exploring alternatives that are safer for humans and the environment. Among these alternatives is the use of plant extracts; however, plant extracts have various disadvantages, including the instability of their compounds that evaporate with time, thereby reducing their effectiveness. With the development of nanotechnology and its applications, researchers are focused on testing the performance of plant-based nanocomposites for eliminating pests. Numerous issues with agricultural and insect pest control can be addressed by using nanotechnology, including increasing the physical stability, water dispersion, and bioavailability of oil emulsions and coating the desired surface area with small oil droplets. Thus, issues with essential oil application, such as volatility, low water solubility, and oxidation, can be resolved by using nanoformulations. These nanoformulations progressively release active ingredients on site, reducing the toxicity for nontarget species and demonstrating their potential as substitutes for synthetic pesticides in the management of stored-grain pests. Research on nanoemulsions from plant sources and their role in controlling stored-product coleopteran insects was reviewed with emphasis on articles from 2014 through 2023. This review compiles important data for this field of research, providing information for design of future studies.

The fruit fly Neoceratitis asiatica (Becker) (Diptera: Tephritidae) is a monophagous pest that damages only wolfberry, Lycium barbarum L. The odorant-binding proteins (OBPs) of insects are part of the initial steps of the olfactory signal transduction cascade involved in solubilizing and transporting chemical signals to the olfactory receptors. We studied the OBP genes of N. asiatica by using data from RNA-seq cDNA libraries of adult flies. Seventeen putative OBP sequences in N. asiatica were identified, corresponding to 13 OBPs of Drosophila melanogaster (Megen) (Diptera: Drosophilidae). Thirteen of the N. asiatica genes belong to the classic subfamily, four are in the minus-C subfamily, and none were members of the plus-C and dimer subfamilies. A phylogenetic tree was constructed to elucidate the evolutionary relationship between N. asiatica and other related species. This investigation of OBP evolution in monophagous, oligophagous, and polyphagous fruit flies revealed that the OBPs in N. asiatica are more oligo and conserved. These findings lay a foundation for uncovering the relationships between monophagous insects and their OBPs.

We conducted a case study on the severe damage caused by the transboundary migration of Locusta migratoria (L.) (Orthoptera: Acrididae) in the Tacheng Prefecture and the Altay Prefecture at the China–Kazakhstan border by examining the effects of terrain on their landing behaviors. Based on the time and location of the locusts' mass landings, we used mesoscale weather research and forecasting models to test the sensitivity (horizontal wind, vertical wind, temperature, and rainfall) of the terrain and simulate the effects of different terrain heights (terrain leveling, half terrain height, and actual terrain height) on landing. The results showed that changes in the regional terrain of the Tacheng and Altay prefectures did not enhance the vertical airflow over the landing area. With an elevation of the terrain, the precipitation intensity in the landing area of locusts also did not increase. We did detect a direct impact of wind direction and changes in temperature in the regional terrain on the landing process of L. m. migratoria. With an increase in terrain altitude, the wind direction over the landing area changed and the temperature decreased, resulting in large-scale forced landing. The results of this study have important value in predicting and forecasting the arrival of migratory locusts.

Imidacloprid, a neonicotinoid insecticide, is efficacious against hemipterans, including the brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). However, frequent use of this insecticide has resulted in the development of high levels of resistance among brown planthopper populations. Endosymbionts of insects have contributed to host physiology and evolution and play a role in resistance to chemical toxins. In this study, polymerase chain reaction–denaturing gradient gel electrophoresis was used to analyze the bacterial and yeast-like symbiont communities of imidacloprid-resistant and -susceptible brown planthopper populations. The Shannon-Weaver diversity index and the evenness index indicated no differences in the richness and the expression of overall species distribution of the symbiotic communities of resistant and susceptible populations. The similarity coefficients of 0.53 and 0.56 for bacterial and yeast-like symbionts, respectively, indicated the main types of differences among microorganisms in resistant and susceptible populations. Sequence comparison analysis indicated the bacterial species in the susceptible population were members of the Enterobacteriaceae and Moraxellaceae, and those in the resistant population were members of the Enterobacteriaceae, Oxalobacteriaceae, Rhodobacteriaceae, and Sphingomonadaceae. Differences also were found in the composition of yeast-like symbionts of the two populations; Cryptococcus luteolus, Pseudozyma aphidis, and Pseudozyma antarctica were detected in the susceptible population, and Cladosporium perangustum was detected in the resistant population.

Aedes aegypti (L.) (Diptera: Culicidae) management in Mexico primarily involves destruction of breeding sites and application of insecticides. There are many cases of field resistance and few studies on the instability of this phenomenon, despite its usefulness in management of this pest. The goal of this research was to estimate, under laboratory conditions, the stability of resistance to permethrin and malathion in 3 field-collected Mexican populations of Ae. aegypti. Early fourth-instar larvae were used for the bioassays according to the methodology of the World Health Organization (WHO). Initially, we estimated the level of insecticide resistance in F₁ larvae. Then, each population was individually reared without selection pressure through 7 generations, and the insecticide response was monitored and compared with the susceptible New Orleans strain. The resistance response (RR₉₅) to permethrin in the F₁ generation varied from 53.8 to 267.9X at the LC₉₅ level. In malathion, the RR₉₅ of the F₁ generation ranged from 5.6 to 10.5X. In most cases, the highest rate of resistance decline occurred from F₁ to F₂. The response to permethrin and malathion after 7 generations without selection pressure was similar to that observed in the susceptible reference strain.

The pecan nut casebearer, Acrobasis nuxvorella Neunzig (Lepidoptera: Pyralidae), is a monophagous pest attacking pecan, Carya illinoinensis (Wangenh.) Koch. Pheromone traps attractive to adult males are used to monitor this pest in orchards by placing them in the lower canopy. However, some insects exhibit vertical stratification in tree canopies as does occur for some beneficial and pest species associated with pecan. The objective of this study was to assess vertical stratification of the pecan nut casebearer in the canopy of tall pecan trees when sampling with pheromone traps. Traps were placed at three heights in orchards (1.5, 7.6, and 13.7 m) above ground. In one experiment, only one trap was placed at one of the three heights at a tree. In the other experiment, three traps, one at each height, were placed in the canopy of the same tree. Results from both experiments reveal that the pecan nut casebearer does stratify within the pecan canopy. Significantly more moths were captured in the highest trap than in the traps at the other heights. These results provide information useful for developing pecan nut casebearer management strategies such as mating disruption in pecan orchards with tall trees.

A staphylinid beetle morphotype, Mesostaphylinus orapa sp. n., is described based on a single well–preserved compression fossil from an Upper Cretaceous lacustrine deposit at Orapa Diamond Mine in Botswana. Mesostaphylinus Zhang is placed in the extant subfamily Paederinae based on general habitus and an unambiguous synapomorphy, the concealed antennal insertions. Mesostaphylinus is a genus of convenience for fossils belonging in Paederinae, but lacking diagnostic features (e.g., maxillary palpomeres) to assign and delineate them into appropriate tribes and subtribes. The fossil described here is morphologically similar to M. laiyangensis Zhang, M. fraternus Zhang, Wang and Xu, M. elongatus Solodovnikov and Yue, M. yixianus Solodovnikov and Yue, and M. antiquus Solodovnikov and Yue. Compared to other fossil staphylinid beetles that have been described thus far, the fossil also portrays morphological conservatism, morphological stasis, or arrested evolution dating back to the Cretaceous, thereby suggesting a punctuated equilibrium pattern of evolution.

Systena frontalis (F.) is an insect pest of nursery production systems in the Midwest, Southeast, and Northeast regions of the United States. Adults feed on plant leaves and can reduce salability of container-grown nursery plants. Limited management options are available to protect plants from S. frontalis adult feeding damage. Insecticide spray applications to plant leaves are labor-intensive and not cost-efficient. Systemic insecticide applications to the growing medium may protect plants from S. frontalis adult feeding. In 2023, we conducted two laboratory and two greenhouse experiments to assess the residual activity of the systemic insecticides dinotefuran, thiamethoxam, and acephate against field-collected populations of S. frontalis adults. In the laboratory experiments, growing medium containing Itea virginica L. ‘Little Henry’ plants were treated with these three systemic insecticides. Twenty-five and 45 d after treatments were applied, leaves were collected and placed into petri dishes with a single S. frontalis adult. In the greenhouse experiments, Itea plants were placed into plastic observation cages. Eight S. frontalis adults were released into each cage with a single Itea plant. In the laboratory experiments 25 and 45 d after application of dinotefuran and thiamethoxam, the S. frontalis adults in the dishes with treated leaves had 66–90% mortality after 72 h. In the greenhouse experiments, dinotefuran and thiamethoxam protected Itea plants from S. frontalis adult feeding 45 d after application; 2.4 and 2.8 mm² of leaf area were fed upon by S. frontalis adults. These results indicate that systemic insecticides can reduce feeding damage by S. frontalis adults on container-grown nursery plants.

The kudzu bug, Megacopta cribraria (F.) (Heteroptera: Plataspidae), is native to Asia, was first detected in Georgia, USA, in 2009, and has since been recognized as a damaging pest of soybean (Glycine max (L.) Merrill; Fabales: Fabaceae) in several southeastern states. Megacopta cribraria dispersed rapidly from 2009 to 2013, after which its spread rate declined sharply. Despite this decline, established populations have remained stable. This decline may be partially attributed to natural enemies of kudzu bug. For example, the exotic egg parasitoids Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae) have been occasionally detected in the United States since 2016 and 2013, respectively. We recovered O. nezarae from M. cribraria eggs collected from wild patches of kudzu (Pueraria montana Lour. (Merrill) var. lobata (Willd.)) throughout summer 2017. Although the occurrence of O. nezarae in southern Georgia has been suggested based on exit holes from kudzu bug eggs, to our knowledge, this report is the first to document and confirm recovery of O. nezarae from kudzu bug eggs in both Tennessee and Georgia. In addition, at the time of collection in 2017, this recovery was the first confirmation of this species from kudzu in North America. This early-season natural enemy combined with the later-occurring entomopathogen Beauveria bassiana (Balsamo-Crivelli) Vuillemin may reduce and maintain kudzu bug densities, which could lessen economic impacts on soybean producers.

The sweetpotato whitefly, Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae), continues to be a major pest of vegetable cultivation in Georgia, USA. Field-by-field surveying is an effective approach to determining the susceptibility status of a B. tabaci population to an insecticide. During 2020–2022, a modified maximum dose bioassay method was tested to characterize the insecticide response of B. tabaci field populations to several commonly used insecticides for whitefly management in Tift Co., GA, and the surrounding areas. A rapid bioassay was used for these evaluations that allowed for field assessments before spray applications to reduce the adult life stage of this species. The results of the evaluations were produced within 24-h following a 24-h root drench period. Our survey suggests that the neonicotinoids dinotefuran and flupyradifurone were the most effective insecticides from the Insecticide Resistance Action Committee (IRAC) group 4A. Cyantraniliprole was also effective, with 88 and 86% adult mortality following exposure to the high (maximum) and low doses, respectively. Conversely, the levels of control using another diamide, cyclaniliprole, were notably lower. Adding a low dose to the high dose provided an early indication of inefficient control with a product potentially indicating an increase in resistance. Specifically, a significant difference between the high and low doses suggests that the dose–response curve had shifted toward resistance development in each B. tabaci field population. The proposed bioassay method is meant for systemic insecticides that offer quick responses on adults. The use of this efficient method will improve evaluations prioritizing insecticides for use or rotation in an insecticide resistance management program.

Based on transcriptome data of adults and pupae, 3 Minus-C OBPs (odorant binding proteins) genes were cloned and analyzed in various tissues (including head, thorax, abdomen, legs of female and male adults, and wings of males) of Apocheima cinerarius Erschoff (Lepidoptera: Geometridae). Expression patterns were examined across the developmental stages of egg, larva (1st–5th instars), pupa (non-diapause and diapause), and adults. The qRT-PCR results revealed a significant up-regulation of OBP8 in 3rd and 4th larval instars, with the highest expression level observed in 4th-instar larvae. OBP14 exhibited higher expression levels in diapausing pupal and adult stages, with highest levels in the female adult. Conversely, OBP18 displayed highest expression in the non-diapausing pupae, while exhibiting extremely low expression levels among other stages. The tissue expression profile revealed a gradual increase in the expression of OBP14, with highest levels in the male legs, whereas the expression pattern of OBP18 exhibited an inverse trend with maximum expression observed in the male head (including antennae). OBP8 exhibited high expression levels in the abdomen of the female adult, while OBP14 showed high expression in the legs of the male adult. Additionally, OBP18 displayed high expression in the female head. These findings suggest the crucial role played by OBP genes in both olfactory and non-olfactory tissues of A. cinerarius. The results provide a fundamental basis for further investigation into the recognition of odorant binding in A. cinerarius.