Debate over resistance management tactics for genetically engineered (GE) crops expressing insecticidal toxins is not new. For several decades, researchers, regulators, and agricultural industry scientists have developed strategies to limit the evolution of resistance in populations of lepidopteran and coleopteran pests. A key attribute of many of these events was insecticide resistance management (IRM) strategies designed around a presumed high-dose expression sufficient to kill 99.5% of exposed larvae for some of the main target pests in corn, Zea mays L. and cotton, Gossypium hirsutum L. In contrast, other target pests did not meet this high-dose criterion. Similarly, the recent release of ThryvOn cotton that expresses thysanopteran and hemipteran active Mpp51Aa2.834_16 toxin is not high dose, working on a combination of behavioral and sublethal effects to suppress populations. This unique mode of control has generated considerable uncertainty about what IRM strategies will be most effective to limit field-evolved resistance to this unique spectrum of pests. The goal of this manuscript is to present several knowledge gaps that exist in proposed Mpp51Aa2 IRM plans, focusing on its activity on thrips, Frankliniella spp. Addressing these gaps will be crucial to limit resistance and preserve the benefits that this technology may provide by alleviating reliance on conventional insecticides and seed treatments. Broadly, these considerations will be important for future GE events that are non-high dose but remain valuable components of a more holistic insect management programs that integrate multiple tactics to reduce conventional insecticide use for challenging pests.

Insect pheromones are critical chemical signals that regulate intraspecific behavior and play a key role in the dynamic monitoring and control of pest populations. Historically, research on insect pheromones has primarily focused on lipid-based compounds. However, terpenes and terpenoids, which are widely occurring classes of bioactive compounds, also play significant roles in insect pheromone blends. Over 50 terpene and terpenoid-based pheromones have been identified in over 52 insect species, spanning various orders such as Coleoptera, Hymenoptera, Blattodea, Hemiptera, Diptera, and Lepidoptera. These compounds are associated with several types of pheromones, including female or male sex pheromones, aggregation pheromones, alarm pheromones, and aphrodisiac pheromones. Terpenes and terpenoids may act as either primary or secondary components of pheromone blends and influence a wide range of critical insect behaviors. They play essential roles in the physiological and ecological adaptation of insects to their environment.This review provides a comprehensive overview of current research on terpene and terpenoid-based pheromones in insects, examining their structures, types, and physiological and ecological functions. Additionally, we propose future research directions to guide the application of these pheromones in insect behavioral regulation and pest management, while advocating for their broader use in insect pest monitoring and control.

Insects provide important pollination services for cops. While land use intensification has resulted in steep declines of wild pollinator diversity across agricultural landscapes, releasing managed honeybees has been proposed as a countermeasure. However, it remains uncertain whether managed honeybees can close the pollination gap of sunflower (Helianthus annuus L. [Asterales: Asteraceae]) in areas lacking wild pollinators, and how the benefits of honeybees to sunflower production are modulated by soil nutrients. We investigated the effects of 3 pollination treatments (open, self and hand pollination) on sunflower yield parameters. We also estimated the pollination efficiency of managed honeybees (Apis mellifera L. [Hymenoptera: Apidae]), and analyzed the effects of honeybee visitation and soil nitrogen on sunflower yield parameters. Insect pollinators contributed 73% of seed set and 69% of the weight of filled seeds per head in the open pollination of sunflowers, but large pollination deficits still existed. Insect pollination may enhance sunflower yield by augmenting the number and weight of filled seeds per head, but not by altering the total number of seeds. Except for the total number of seeds per head, yield parameters increased significantly with the number of honeybee visits. Low nitrogen accelerated the positive effect of honeybee pollination on sunflowers, and alleviated the negative effect of distance of beehives on honeybee visitation rate. We conclude that managed honeybees could be used to pollinate sunflowers in areas with the shortage of wild pollinators, and sunflower production may benefit from shortening the distance of beehives and lowing of nitrogen fertilizer inputs.

Bombus terrestris, an important eusocial insect, plays a vital role in providing pollination services for both wild plants and greenhouse crops. For the development of the colonies, the workers must leave the hives to collect nectar and pollen. However, limited findings about the foraging behavior of B. terrestris workers (e.g., first foraging period, total foraging duration, and daily foraging bouts). Here, radio-frequency identification (RFID) technology was used to monitor the continuously foraging behavior of B. terrestris workers during August and October, 2021 and August, 2023. The findings of our study indicate that the participation rate in the foraging activity among adult workers was 65.07%. In addition, it was observed that adult workers initiate their initial foraging activities on the second day, with the majority commencing their first foraging endeavors between the ages of 3 and 5 days. It is noteworthy that worker bees will remain within the confines of the hive for the entirety of their lifespan, if they do not begin their first foraging within the first 12 days. Our results also revealed that workers were mainly foraged from 7:00 AM to 10:00 AM and 14:00 PM to 17:00 PM in August, while, and predominantly from 12:00 to 15:00 in October. Furthermore, it was shown that foraging efficiency was notably greater during seasons marked by a plentiful availability of flower resources. This was supported by an observed rise in the frequency of daily foraging activities and the overall duration of foraging.

Graphical Abstract

Pollination by insects is vital for global agriculture, with honey bees (Apis mellifera L.) being the most important pollinators. Honey bees are exposed to numerous stressors, including disease, pesticides, and inadequate nutrition, resulting in significant colony losses.This study investigates the use of drone brood to mitigate these problems. Drone brood, which is normally discarded during varroa mite (Varroa destructor, Anderson and Trueman) management, is rich in proteins, fats, and essential minerals. We compared drone brood with an already suggested pollen supplement (Tenebrio [Tenebrio molitor L.] flour).The results indicate that drone brood flour is a viable source of proteins, fats, and minerals and is potentially antimicrobial due to its high content of elements with known antimicrobial properties. It meets the nutritional needs of honey bees while mitigating the effects of varroa mites. The use of drone brood flour can provide high-quality beeswax, surplus of pollen, and improve bee health, which promotes sustainable beekeeping.

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The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a polyphagous pest recognized as composed of several cryptic or sibling species. The Middle East-Asia Minor 1 (MEAM1) and the Mediterranean (MED) putative species are invasive and destructive worldwide. The MEAM1 is established throughout the United States, while MED is documented in 27 states. This study determines the status of MED in Oklahoma and develops and validates a high-resolution melting (HRM) assay for discrimination of MEAM1 and MED. In August–October 2022, whiteflies were collected from different host plants in Stillwater, Oklahoma, and identified as species based on analysis of a diagnostic fragment of the mitochondrial cytochrome oxidase I (mtCOI) gene. MED was found in mixed infestations with MEAM1 on both sweetpotato in a greenhouse and cucumber in the field. Other cryptic species were not detected. Sequencing followed by phylogenetic analysis indicated that the MED specimens belonged to the Q2 mitotype. Additionally, the secondary endosymbionts in captured and progeny whiteflies were identified. For rapid discrimination of MEAM1 and MED species, an HRM assay using a single set of primer pairs targeting the mtCOI gene was developed. Species discrimination was tested in 2 laboratories using MEAM1 and MED Q2 mitotype genomic DNA, and a synthetic plasmid containing the MED Q1 mitotype mtCOI fragment. The HRM assay was validated to discriminate MEAM1 from MED Q1 and Q2 mitotypes. This is the first report of B. tabaci MED in Oklahoma and reinforces the need for continued monitoring of this insect species complex.

Bell pepper endornavirus (BPEV) Alphaendornavirus capsici (Endornaviridae) is an RNA virus that infects many pepper (Capsicum annuum) horticultural types and is seed transmitted. BPEV does not cause apparent symptoms and is found at every plant developmental stage. During the domestication of bell pepper, plant breeders, unaware of the existence of endornaviruses in the germplasm, selected endornavirus-infected genotypes.This could be an indication that the presence of endornaviruses in this crop is beneficial. Among the possible beneficial effects that endornaviruses may provide to their host could include tolerance or resistance to biotic and abiotic agents and, therefore, may have evolved a symbiotic relationship with their hosts. With this in mind, we set out to determine host preference, host suitability, and population dynamics of green peach aphid Myzus persicae (Sulzer) on BPEV-infected and virus-free bell pepper near-isogenic lines. During choice bioassay experiments, we observed that a higher proportion of M. persicae adults settled on BPEV noninfected leaves as compared to BPEV-infected leaves. Life table analysis revealed that M. persicae performed less well on BPEV-infected leaf tissues, with reductions in longevity, progeny, and intrinsic rate of increase.These results indicate BPEV is beneficial to its host, protecting against an important generalist pest.

The yellow mealworm, Tenebrio molitor, L., can be an important component of the circular economy because of its ability to transform a variety of agricultural wastes and byproducts into valuable livestock feed. Analysis of their ability to endure toxins coupled with their potential to transfer contaminants to higher trophic levels is not complete. Fumonisins, produced primarily by Fusarium verticillioides (Hypocreales: Netriaceae) (Sacc.) Nirenberg (1976), are mycotoxins likely to be encountered by T. molitor in corn and other grain byproducts. Tenebrio molitor larvae were reared on a simulated diet of corn and other grain byproducts treated with a range of maximum recommended fumonisin B₁ levels for different livestock feeds. We observed that T. molitor were able to survive, grow, and reduce by excretion and metabolism their retained fumonisin B₁ levels by up to 99.7% compared to the diet they consumed. Unknown metabolic processes were inferred from the significantly reduced content of fumonisin B₁ in the frass (63.1% to 73.2%) as compared to the diet and by the first report of long-chain acylated fumonisin B₁ derivatives in insect frass.

The yellow mealworm, Tenebrio molitor L., is one of the most important industrialized insects worldwide. As a poikilotherm, T. molitor requires a temperature-regulated environment for its farming. Currently, the farming of T. molitor uses temperatures between 29 and 31°C determined to be optimal for maximizing growth. This study was aimed to test and determine optimal temperature for T. molitor impacting all stages including their development, reproduction, and fitness. Pupae of T. molitor were exposed to 8 different temperatures (18, 21, 24, 27, 30, 33, 36, and 39°C). Developmental rates (=1/d to develop) were calculated at 8 temperatures and fitted in a poikilotherm model to determine the temperature with the highest developmental rate (developmental maximum, T_o).The developmental maximum was 33°C and the thermal maximum (t_m) (lethal temperature) was 39°C. The biological and demographic parameters of T. molitor were compared at 3 favorable temperatures below the T_o (31, 29, and 27°C) to determine the fitness of T. molitor populations. Fecundity and egg viability were the highest at 27°C (5.25 eggs/female/d and 73.99%, respectively) and the lowest at 31°C (1.55 eggs/ female/d and 27.14%, respectively).The shortest larval development time was observed at 27°C and the longest at 31°C (142.81 and 161.97 d, respectively).The highest fitness was observed at 27°C with a population doubling time of 32.78 d compared to 40.58 and 239.4 d at 29 and 31°C, respectively. In conclusion, 27°C is closer to the optimal temperature for T. molitor productivity than 29°C, thus reducing its farming energy needs.

Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) and Spodoptera exigua Hübner (Lepidoptera: Noctuidae) pose substantial threats to many crops, necessitating the exploration of biopesticides as potential chemical alternatives. One alternative is baculoviruses; however, their instability in the field has hindered their widespread use. Host plant phylloplane affects baculovirus activity at varying levels in different host plants. Formulation contributes significantly to optimizing the baculoviral stability on different phylloplanes against environmental conditions; however, it is expensive and difficult to make in developing or nondeveloped countries. In the current study, we developed a simple tank-mix application (MBF-Tm5) for immediate use, resembling the characteristics of a suspension concentrate formulation for Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) and Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV). We examined their biological activity against 2^nd instar larvae first on an artificial diet under laboratory conditions and on eggplant and pepper phylloplane in greenhouse conditions compared to plain viruses. This formulation exhibited no significant improvement in the biological activity of both viruses on an artificial diet under laboratory conditions but significantly improved the biological activity of both viruses on both plants under greenhouse conditions. The original activity remaining (OAR%) of both unformulated and formulated viruses decreased over time under greenhouse conditions; however, the OAR value of both viruses on eggplants was significantly higher than on pepper plants. Overall, the tank-mix simple formulation of baculoviruses might be a great alternative for improved stability in nature, providing better control.

The lesser mealworm Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), an important insect pest of stored-product commodities and poultry production systems, is regarded among the most difficult species to control. It has developed resistance to many chemical insecticides, and though various cultural and biological methods have been assessed and identified as possible factors for its control, none are currently implemented. Entomopathogenic nematodes are often successfully employed as alternative to chemicals biocontrol agents of various insect species, including pests of stored products; nevertheless, their evaluation as potential biocontrol factors of the lesser mealworm is not efficiently scrutinized. In the current study, single A. diaperinus larvae were exposed to six doses of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), and Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae), for 4 and 8 d, and mortality was recorded at 3 different temperature regimes, i.e., 25 °C, 30 °C, and 35 oC. The study concludes that S. carpocapsae and S. feltiae are both highly virulent against A. diaperinus larvae and may be considered as promising biological control agents for reducing lesser mealworm infestations when applied at a rate of 70 IJs/cm² at 25 oC. When assessed at 30 °C, both species were effective at the same rate though causing lower mortality of ∼60% and ∼50%, respectively, whereas their efficacy was low at 35 oC.

Megalurothrips usitatus (Bagnall) (Thysanoptera:Thripidae) is an important pest of cowpeas, Vigna unguiculata (L.) Walp., and can cause severe damage to the crop. Lasioseius lindquisti (Tseng) (Acari: Blattisociidae) and Lasioseius scapulatus (Kennett) (Acari: Blattisociidae) are 2 mites used against M. usitatus in Hainnan, China. The functional responses of these mites were examined in the laboratory. Lasioseius lindquisti showed a type III functional response, with a maximum prey consumption of 22.38 ± 0.63 per day. Its optimal search density for each unit in this experiment was 10.27 ± 0.50 per day. Lasioseius scapulatus showed a type II functional and an attack rate on 1st instars of M. usitatus of 0.83 ± 0.23.The handling time (h) of L. scapulatus was 0.074 ± 0.018 (means ± SE), while the maximum attack rate (T/Th) of adult females on 1st instar thrips was 13.51. Our results showed that both L. lindquisti and L. scapulatus are potentially useful predators of M. usitatus.

Cacopsylla chinensis is an oligophagous pest and has become one of the main pests that cause yield loss in commercial pear orchards in China. Predicting the impact of climate change on the distribution range of C. chinensis is crucial for its effectively preventing and managing. In this study, we collected 102 geographic distribution information of C. chinensis with 8 selected crucial environmental variables to simulate its potential suitable habitats. On this basis, the parameter-optimized maximum entropy model was utilized to predict the potential effect of future climate variation on its distribution, considering various socio-economic pathway scenarios and 3 Earth system models.The findings showed that the current total potential suitable area for C. chinensis was 578.29 × 10⁴ km², which accounts for 60.24% of China's territory. In the total area, the suitability areas of low, medium, and high were 308.21 × 10⁴ km², 118.50 × 10⁴ km², and 151.58 × 10⁴ km², respectively. Among them, the high suitability areas are mainly distributed in Anhui, Beijing, Chongqing, Hebei, Henan, Hubei, Jiangsu, Liaoning, Shandong, Shanxi, Shaanxi, Sichuan, andTianjin. Furthermore, our predictions suggest that the potentially suitable areas for this pest will increase by 8.49–35.02% under various future climate change conditions in China. The findings will be propitious to understand the linkage between C. chinensis niches and the relevant environment. It also provides valuable insights for developing future pest management strategies.

Graphical Abstract

Invasive species pose a threat to ecosystems and humans worldwide, which is exacerbated by climate change, causing the expansion of species distributions. Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) causes leaf drying and shedding in eucalyptus trees, forming blister-like galls that negatively impact the growth of the trees. Closterocerus chamaeleon (Hymenoptera: Eulophidae) is a recognized parasitoid of O. maskelli. This study used the MaxEnt and CLIMEX models to predict the potential distribution under current and future climate scenarios for O. maskelli and its natural enemy, C. chamaeleon.The MaxEnt model result indicated that isothermality was the most critical factor predicting the distribution of O. maskelli, while the mean temperature of the driest quarter was the most critical factor predicting the distribution of C. chamaeleon. Under current climate conditions, the CLIMEX model predicted a wider potential distribution for O. maskelli and a smaller distribution for C. chamaeleon than the MaxEnt model. MaxEnt and CLIMEX prediction results indicated that South America and Africa were suitable for O. maskelli and C. chamaeleon. The MaxEnt model indicated that under SSP245 climate conditions, the potentially suitable regions for these species expanded, while under the SSP126 climate scenario, the region contracted significantly. The CLIMEX model indicated that under the A1B and A2 climate scenarios, the marginally suitable areas increased, while the moderately and highly suitable areas decreased. This study provides a theoretical basis for creating early monitoring, quarantine, and control methods for invasive pests.

Hylurgus ligniperda (Fabricius) is an important pest that attacks Pinus species in China. It impacts the vitality of local pine vegetation, reduces the ability to prevent windbreak and sand fixation, and causes ecological loss. MaxEnt and ArcGIS are used to predict and analyze the changes in suitable distribution areas of H. ligniperda under current and future climate scenarios, based on 12 climate factor datasets and 1,001 field distribution data points for this pest. The environmental variables used significantly influence the potential distribution of H. ligniperda. Highly suitable areas of this beetle are located in western Europe, central Asia, and the southeastern regions of Oceania, with sporadic occurrences across North America, South America, and Africa. Highly suitable areas in China occur across the east, central south, and southwest regions. There is a significant increase in the high and medium suitability areas, while the area of low suitability decreases under the 4 future climate scenarios (SSP126, SSP245, SSP370, and SSP585). The suitable distribution area for H. ligniperda shows an overall trend of moving northwestward. The purpose of this current study is to provide important theoretical support for the prevention and management of this pest by predicting and analyzing suitable distribution areas under current and future climate scenarios.

Graphical Abstract

Sugarcane borers (SCB) pose a major threat to sugarcane production. Effective pest management requires detailed knowledge of SCB phenology and population dynamics in responses to environmental changes. This study tested the hypothesis that drought drives SCB outbreaks and identified season-specific effects by investigating large-scale field data of these pests in 4 key sugarcane-growing provinces in south subtropical and tropical China (Guangxi, Guangdong, Yunnan, and Hainan) from 1987 to 2018. The standardized precipitation evapotranspiration index was used as a drought indicator at various time scales. We found that drought during a specific month can result in significant changes in the annual SCB outbreak status, such as November in Guangxi, June in Yunnan, and September in Hainan. By summarizing seasonal effects of drought across study locations, we found a general pattern that SCB outbreaks increased with drier conditions in summer, whereas they were promoted by wetter conditions in fall.This research provides crucial knowledge for predicting SCB outbreaks under seasonal and climate changes. This information is also highly critical for increasing the efficiency and accuracy of integrated pest management strategies.

The papaya mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae), poses a serious threat to global trade and is classified as a quarantine pest in some countries. Phosphine (PH₃) is considered an alternative to methyl bromide for postharvest control of P. marginatus. However, reports addressing the impact of PH₃ treatment to control P. marginatus on succulent plants are lacking. This study aims to investigate the effects of PH₃ fumigation alone and in combination with ethyl formate (EF) on insecticidal activity across all developmental stages of P. marginatus and its influence on the quality of plant products. Tolerance tests showed that among all developmental stages, the egg stage of P. marginatus is the most tolerant to PH₃ treatment. A concentration of 1 g m^–3 PH₃ for 8 h exposure at 25 °C achieved a 99.9968% (Probit-9) mortality rate for the eggs. Additionally, we examined the synergistic effects of combining EF with PH₃. Combined fumigation with 0.5 g m^–3 PH₃ and 2 g m^–3 EF for 8 h at 25 °C did not adversely affect the lifespan and quality of three succulent plant species, achieving an effective dose of 0.99991. These findings suggest that PH₃ fumigation, with or without EF, are effective treatments for postharvest control of P. marginatus in succulent plants.

Graphical Abstract

The mass production of insects for food and feed is an expanding North American industry. Facilities that mass rear insects are at risk of pest infestations because the optimal environmental conditions for rearing beneficial species may also support the development of pest species. Here, we present the first recorded results detailing the interactions between dermestids and farmed crickets. Cricket farms have reported extremely low harvest yield during heavy dermestid infestations, but the exact reasons for this low yield are unknown. Many dermestid larvae are covered in dense, detachable, barbed setae called hastisetae, which are used by the larvae as an active trapping system against arthropod predators. We designed a series of experiments to test the hypotheses that a dermestid pest of cricket farms, black larder beetle (Dermestes ater DeGeer (Coleoptera: Dermestidae)), may be directly impacting Gryllodes sigillatus Walker (Orthoptera: Gryllidae) yield through the physical effects of hastisetae ingestion and/or indirectly impacting cricket yield through competition for fishmeal, a primary source of protein in conventional cricket feed. Our predictions that G. sigillatus life history and survival would be negatively affected by dermestids were largely refuted. Females fed infested diets grew less mass, but not smaller body size, compared to females fed uninfested diets. We also found that while G. sigillatus experienced delayed growth early in life after living with dermestids, they were able to tolerate living with, and consuming, dermestid larvae. We discuss how these findings have led to new hypotheses concerning how dermestid infestations drive reductions in cricket farm yield.

The solitary bee Osmia excavata (Hymenoptera: Megachilidae) is a key pollinator managed on a large scale. It has been widely used for commercial pollination of fruit trees, vegetables, and other crops with high efficiency in increasing the crop seeding rate, yield, and seed quality in Northern hemisphere. Here, a high-quality chromosome-level genome of O. excavata was generated using PacBio sequencing along with Hi-C technology. The genome size was 207.02 Mb, of which 90.25% of assembled sequences were anchored to 16 chromosomes with a contig N50 of 9,485 kb. Approximately 186.83 Mb, accounting for 27.93% of the genome, was identified as repeat sequences. The genome comprises 12,259 protein-coding genes, 96.24% of which were functionally annotated. Comparative genomics analysis suggested that the common ancestor of O. excavata and Osmia bicornis (Hymenoptera: Megachilidae) lived 8.54 million years ago. Furthermore, cytochrome P450 family might be involved in the responses of O. excavata to low-temperature stress.Taken together, the chromosome-level genome assembly of O. excavata provides in-depth knowledge and will be a helpful resource for the pollination biology research.

The mirid bugs Lygus hesperus (Knight) and L. elisus (van Duzee) are key pests of forage, fiber, and fruit crops. Our goals were to identify pheromone components produced by females of both species and to develop practical pheromone dispensers for use in monitoring these pests. Volatiles collected from virgin female L. elisus contained (E)-2-hexenyl butyrate (E2HB) as the major component with lesser amounts of hexyl butyrate (HB) and (E)-4-oxo-2-hexenal (E4OH) (ratio 117.2:100:17.1, respectively), whereas volatiles and solvent extracts from L. hesperus contained HB and E4OH as major components, with only small amounts of E2HB (100:23.6:3.4, respectively in volatiles). Dispensers fabricated from pipette tips released the components at ∼10 µg/d in a ratio similar to the loading ratio.These lures were used to optimize the pheromone blends in field studies from 2012 to 2017. Blends of E2HB and E4OH attracted L. elisus, and a 100:60 blend was optimal. Blends of HB and E4OH attracted L. hesperus, and a 100:60 blend was adopted as a base blend.The additions of possible minor components such as (Z)-3-hexenyl butyrate, (E)-2-hexenal, or 1-hexanol did not improve the attraction of L. hesperus. In trials in alfalfa and strawberry, traps baited with blends of HB:E4OH (100:60) were equally or more effective for monitoring L. hesperus than sweep or vacuum samples, with pipette tip dispensers lasting 2–3 weeks under field conditions. The numbers of L. hesperus captured were lower than expected as compared with reports of pheromone trapping for other Lygus spp. Some possible reasons were investigated.

Invasive species pose significant ecological and economic threats globally. Zaprionus tuberculatus Malloch, a drosophilid fruit fly native to the Afrotropical region and Indian Ocean islands, is included in the pest list of the Center for Agriculture and Bioscience (CABI) because it uses fruit as breeding sites and can damage cultivated areas.This fly species extended its range across Europe in the late 20th century; in 2020, it was recorded in South America, and currently, it is widely distributed in Brazil. Here, we assess the potential spreading of Zaprionus tuberculatus in Central and North America based on 2 distinct origins of propagules: from South America and from Europe. To this end, we developed species distribution models using bioclimatic variables and elevation data to project potentially suitable habitats and infer invasion routes. In any case, our results indicate suitability for Z. tuberculatus colonization in Central and North America, including major fruit-producing areas in Central American countries and the United States (Florida and California).The rapid dispersal ability of Z. tuberculatus, coupled with its adaptability to diverse environments, underscores the urgency for proactive monitoring and control measures. Therefore, this study provides valuable insights for developing proactive measures to mitigate the spread of Z. tuberculatus and protect agricultural productivity in the Americas.

Arbuscular mycorrhizal fungi may promote growth and stress resilience of plants, particularly under water-deficit conditions. However, interactions among mycorrhizal fungi, wheat plants, and aphids like the English grain aphid Sitobion avenae (Hemiptera: Aphididae) under water-deficit stress are still not well understood. Here, we examined the colonization of the fungus Claroideoglomus etunicatum (Glomerales: Claroideoglomeraceae) on wheat, and its effects on development and behavior of S. avenae under different water regimes.The symbiosis between C. etunicatum and wheat tended to increase the total developmental times of S. avenae nymphs under water deficit, but decreased adult lifespans. Irrespective of water conditions or wheat cultivars (Xinong-979 and Chang-6794), this symbiosis tended to cause higher adult weights and fecundities of S. avenae. These findings suggested that inoculation of this fungus could induce some life history trait trade-offs for S. avenae. Inoculation of C. etunicatum caused significant increases in contents of total amino acids in Xinong-979, and contents of some individual amino acids (e.g., glutamine) in both cultivars. This aphid preferred settling on symbiotic plants, with alate individuals attracted to well-watered Xinong-979 from 4 and Chang-6794 from 24 h postrelease. Increased phloem feeding and reduced pathway phase time for S. avenae were found in symbiotic plants.The fungus C. etunicatum also significantly enhanced wheat growth, especially under water deficit, and increased contents of nonessential and essential amino acids in Xinong-979. Our results highlight complex interactions among fungus symbiosis, wheat cultivars, and water conditions, emphasizing the potential to boost wheat crop resilience in the context of global climate change.

This work aimed to optimize olive fruit fly (OFF) Bactrocera oleae (Rossi) (Diptera: Tephritidae) monitoring and integrated management, thereby ensuring optimal and less-costly decision-making and timely intervention. Field trials in Andalusia (Spain) were undertaken over 2 years to optimize trap model, color, size, and density for the accurate determination of pest spatial distribution and damage as a function of olive cultivar. McPhail traps and yellow sticky panels outperformed the other 4 models with respect to the number of OFF captured. However, McPhail traps caught more natural enemies than yellow sticky panels and so sticky panels were selected to unravel the effect of color on the number of both OFF and natural enemies [hymenopteran parasitoids (Psyttalia concolor) and lacewings (Chrysopidae)] captured. Yellow sticky panels outperformed white, green, and blue ones for the number of OFF captured and captured the fewest natural enemies. When comparing the surface area of yellow sticky panels, 20 × 25 and 10 × 25 cm double-sided panels were equally effective at catching OFF. However, large double-sided yellow sticky panels caught significantly more natural enemies than the small double-sided panels, a key result for developing a less costly and environmentally friendly monitoring system. Furthermore, it was shown that the damage curve had a cultivar-based shape, i.e., for the same population size of OFF the damage caused varied depending on cultivar. Finally, 15 sticky panels per hectare were the optimal number for estimation of OFF spatial distribution.The present research provides key information for new trap design, OFF forecasting, and IPM development.

Graphical Abstract

Grapholita molesta (Busck) (Lepidoptera: Tortricidae) is a major pest of many fruit trees. The large-scale artificial propagation technology of the insect is the basis for the field application of the sterile insect technique and biological control products based on host mass reproduction. However, a low-cost diet with easily accessible materials remains lacking. In this study, we assessed the insect rearing performance feeding on 3 artificial diets: D₁: an artificial diet based on wheat bran and soybean powders; D₂: an artificial diet based on soybean powder, maize powders, and tomato sauce; and D₃: an artificial diet based on soybean powder, maize powder, tomato sauce, and wheat bran, with apples as a control, using 2-sex life table. At 26 ± 1 °C, 70 ± 5% humidity, and 16:8 h L:D photoperiod, the biological indicators of G. molesta fed D₁ were consistent with those fed apples, with a larval stage of 14.88 d, a pupal stage of 7.57 d, adult longevity of 22.69 d, egg deposition count of 223.22, intrinsic rate of increase (r) of 0.1359, finite rate of increase (λ) of 1.1456, and net reproductive rate (R₀) of 94.50. D₁ was used to continuously rear G. molesta population for 5 generations, all life parameters remained normal. These results indicated that the artificial diet based on wheat bran and soybean powder could be used for rearing of the insect. This study proposes an available and cost-effective artificial diet for G. molesta, facilitating the application of green prevention and control technology.

Chemical control is currently the main strategy for managing brown marmorated stink bug, Halyomorpha halys (Stål). However, chemical pesticides can harm nontarget species, including natural enemies of H. halys. Pesticides with high toxicity to H. halys and low toxicity to its parasitoids need to be identified to support H. halys management.This is not only for natural biological control but also for preemptive classical biological control of H. halys by parasitoids. Here, we assessed the contact toxicity of residues of eight insecticides against H. halys and three of its main parasitoid species (Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae), Trissolcus japonicus Ashmead (Hymenoptera: Scelionidae), Trissolcus cultratus Mayr (Hymenoptera: Scelionidae)). This study aims to provide valuable insights for preemptive classical biological control of H. halys using these parasitoids. Our results showed that A. japonicus exhibited higher tolerance to the tested pesticides, while T. japonicus was the most sensitive species. Among the pesticides, chlorantraniliprole had the lowest overall impact on all three parasitoid species. Additionally, acetamiprid, azadirachtin, and rotenone were found to be harmless to A. japonicus. Acetamiprid, however, was slightly harmful to T. cultratus. The remaining pesticides showed moderate to significant harmful effects on the parasitoids. For H. halys adults and fifth instars, the pesticides tested caused no mortality within the 24 h exposure. However, young nymphs were susceptible to the tested pesticides. Fenpropathrin had the highest toxicity to H. halys, killing 83.3%, 52.8%, and 19.4% of second, third, and fourth instars in a 24 h exposure. Fenpropathrin, acetamiprid, cyfluthrin, azadirachtin, and dinotefuran were all slightly harmful to the first instar nymphs. The other pesticides were harmless to H. halys in a 24 h exposure. Halyomorpha halys mortality increased with the contact time with the residue. Mortality of fourth and fifth instars of H. halys was >70% for fenpropathrin, cyfluthrin, dinotefuran, abamectin-aminomethyl, and acetamiprid if exposure continued for 7 d. Acetamiprid was effective in controlling H. halys nymphs but exhibited varying levels of toxicity towards the three tested parasitoid species, depending on the residue age and exposure time. Azadirachtin showed lower overall toxicity to beneficial insects, suggesting that these materials could be used to manage H. halys while minimizing harm to key beneficial species.

Graphical Abstract

Ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) are fungus-farming woodborers that can cause damage to the trees they colonize. Some of these beetles target stressed plants that emit ethanol, and management strategies have proposed using ethanol-injected trees as trap trees to monitor or divert dispersing adult females away from valuable crops. In this study, we used container-grown trees from 8 species to compare the effect of ethanol injection versus flooding on ambrosia beetle host selection and colonization success. Our aims were to understand whether ethanol injection is a suitable technique for different ambrosia beetle species and whether its effectiveness varies depending on the tree species used. In addition, we quantified the amount of ethanol in tree tissues to understand whether ethanol concentration could reflect observed differences among treatments and tree species. Our findings demonstrated that ethanol-injected trees were significantly more selected by both Xyleborinus saxesenii and Xylosandrus spp. and that significantly more adult beetles of both taxa emerged from ethanol-injected than flood-stressed trees. In addition, we showed that ethanol injection can trigger attacks by X. saxesenii and Xylosandrus spp. on a variety of deciduous tree species, nullifying the effects of the species-specific characteristics observed on flood-stressed trees, which can only partially be attributed to the amount of ethanol within the plant.This supported the idea that practitioners can potentially select any species of deciduous trees in management programs for ambrosia beetles based on ethanol-injected trees.

Controlling crop pests while conserving pollinators is challenging, particularly when prophylactically applying broad-spectrum, systemic insecticides such as neonicotinoids. Systemic insecticides are often used in conventional agriculture in commercial settings, but the conditions that optimally balance pest management and pollination are poorly understood. We investigated how insecticide application strategies control pests and expose pollinators to insecticides with an observational study of cucurbit crops in the Midwestern United States.To define the window of protection and potential pollinator exposure resulting from alternative insecticide application strategies, we surveyed 62 farms cultivating cucumber, watermelon, or pumpkin across 2 yr. We evaluated insecticide regimes, abundance of striped and spotted cucumber beetles (Acalymma vittatum [Fabricius] and Diabrotica undecimpunctata Mannerheim), and insecticide residues in leaves, pollen, and nectar. We found that growers used neonicotinoids (thiamethoxam and imidacloprid) at planting in all cucumber and pumpkin and approximately half of watermelon farms. In cucumber, foliar thiamethoxam levels were orders of magnitude higher than the other crops, excluding nearly all beetles from fields. In watermelon and pumpkin, neonicotinoids applied at planting resulted in 4–8 wk of protection before beetle populations increased. Floral insecticide concentrations correlated strongly with foliar concentrations across all crops, resulting in high potential exposure to pollinators in cucumber and low-moderate exposure in pumpkin and watermelon. Thus, the highest-input insecticide regimes maintained cucumber beetles far below economic thresholds while also exposing pollinators to the highest pollen and nectar insecticide concentrations. In cucurbits, reducing pesticide inputs will likely better balance crop protection and pollination, reduce costs, and improve yields.

The invasive pest, spotted wing drosophila (Drosophila suzukii (Matsumura, 1931) or SWD), damages various soft-skinned fruits, severely impacting orchards and vineyards economically. Current sorting practices in commercial production may overlook early-stage SWD infestations, as visible signs take a few days to appear. Our study focused on managing SWD infesting fruits (blueberry, cherry, and raspberry) without visible signs using an artificial atmosphere with elevated CO₂ and low temperature. We hypothesized that these factors affect SWD survival and possibly interact, with potential variations among different soft- or stone-fruit species or varieties. High CO₂ concentrations and cold storage both negatively affected SWD development. A 24-h 100% CO₂ fumigation, without cold storage, significantly reduced SWD infestations in all 3 fruit species studied. On the other hand, 10% CO₂ without cold storage did not cause a significant infestation reduction in cherries. Cold storage alone was too slow to be considered effective. Concurrent low-temperature treatment and CO₂ treatment reduced the insecticidal efficacy of CO₂ fumigation. Optimal fruit sanitation was achieved with a 3-h 100% CO₂ treatment at ambient temperature before cold storage. Raspberries were the most suitable host for SWD development, with over a 5-fold higher SWD development compared to blueberries and over 50 times more than in cherries. We discussed the observed interactions between CO₂ fumigation and chilling and suggested a simple postharvest SWD management protocol using optimal CO₂ levels, exposure times, and chilling periods—achievable without complex equipment.

Commercial blueberry Vaccinium spp. (Ericales: Ericaceae) production relies on insect-mediated pollination. Pollination is mostly provided by rented honey bees, Apis mellifera L. (Hymenoptera: Apidae), but blueberry crop yields can be limited due to pollination deficits.Various hive placement strategies have been recommended to mitigate pollination shortfalls, but the effect of hive placement has received limited formal investigation.This study explores the effects of clumped and dispersed hive placement strategies on honey bee visitation and pollination outcomes in “Bluecrop” and “Duke” fields over 2 years (2021 and 2022) within 2 economically important regions of production in the United States—the Midwest (Michigan) and Pacific Northwest (Oregon and Washington). Clumping hives consistently increased honey bee visitation rate but did not result in higher fruit set, fruit weight, or seed count. Increases in honey bee visitation through clumping could perhaps improve pollination outcomes in more pollination-limited blueberry cultivars and other pollination-dependent crops. Clumping hives is substantially more efficient and cost-effective for beekeepers due to fewer drop locations and could lead to cost savings for both beekeepers and blueberry growers without growers sacrificing pollination levels and crop yields.

The carpophilus beetle, Carpophilus truncatus Murray, 1864 (Coleoptera: Nitidulidae) is an invasive pest recently detected in California's tree nut crop orchards. Here we report a simple, labor-saving, and cost-effective rearing system for C. truncatus utilizing banana and industrial sand components. Banana slices served as both a larval and adult diet source as well as a moisture source to facilitate pupation within the underlying sand. The combination of banana and sand within a single container successfully supported the development of all C. truncatus life stages over multiple generations. The average developmental times recorded in rearing units placed under environmental conditions of 26°C, 60% relative humidity, and 16:8 h (light:dark) photoperiod were: egg to wandering stage larva, 7.54 days; wandering stage to adult, 11.08 days; and adult longevity, 94.33 days. These banana–sand rearing units facilitated the easy collection of all C. truncatus developmental stages, except for eggs.To address this challenge, standalone oviposition chambers utilizing a lima bean-based agar diet were evaluated. These chambers effectively enabled the collection as well as tracking of eggs for different research purposes. The average developmental time recorded for eggs, from initial oviposition to neonate hatching, was 3.20 days. These rearing as well as egg collection approaches provide cost-effective tool to investigate biology, life-history traits and ecology, as well as evaluate approaches to control this invasive pest.

Xylosandrus crassiusculus Motschulsky and Xylosandrus germanus Blandford are serious ambrosia beetle pests in ornamental nurseries. Three ethanol baits, AgBio low release (LR), AgBio high release (HR), and Trécé are commercially available for use in bottle traps to determine flight activity of adult Xylosandrus spp. However, release patterns of ethanol from these baits under varying temperatures and captures of Xylosandrus spp. are poorly understood. Thus, the objectives of this study were (i) to determine ethanol release rates from these baits under constant and variable temperatures and (ii) to compare relative adult Xylosandrus spp. captures using these baits in ornamental nurseries. When 3-d difference (3-d difference) bait weights were recorded under constant 15.6, 21.1, 26.7, and 32.2 °C, an increase in release rates was recorded with an increase in temperature from 15.6 to 32.2 °C for LR bait. At 32.2 °C, no increase or reduction in the 3-d-difference weights was found for the HR and Trécé baits, respectively, compared to LR bait. The 3-d-difference weights were steady with all 3 baits when temperatures gradually increased and decreased in variable sequence for 30 d. In 2022, 2023, and 2024, although all 3 baits captured adult X. crassiusculus and X. germanus, LR bait captured significantly more numbers of X. crassiusculus than the other 2 baits in 2022 and 2023, and in 2024, X. crassiusculus captures were greater in traps with the Trécé bait than the other 2 baits. Thus, ethanol baits can effectively detect the early flight activity of Xylosandrus spp. adults in ornamental nurseries.

This study investigated how management strategies influence resistance profiles in German cockroach (Blattella germanica (L.)) populations and their impact on the performance of commercial gel baits containing fipronil, imidacloprid, and indoxacarb. Field populations from premises managed under 3 different strategies: Baiting, random insecticide (RI) used, and insecticide rotation (IR) were tested. Almost all populations under RI and IR were resistant to deltamethrin, but low to moderate resistance was observed under the Baiting approach. Cytochrome P450 monooxygenases (P450) were involved in deltamethrin resistance in these resistant populations. All individuals under Baiting and RI were homozygous for the L993F mutation, but the populations under IR lacked homozygous-resistant individuals. Eighty-three percent of field populations with complete homozygosity for the Rdl mutation displayed low mortality upon exposure to 3× LD₉₅ fipronil.The effect of P450 and the Rdl mutation conferred high fipronil resistance in populations under the Baiting approach, recording moderate performance indices (PI) of 44–67 in fipronil bait. By contrast, those populations under RI and IR, in which involve glutathione S-transferases in fipronil resistance, had high PIs of 78–93. Almost 80% of populations exhibited over 90% mortality at 3× LD₉₅ indoxacarb treatment, accompanied by high PIs of 90–100 in indoxacarb bait. Partial mortality from 1× LD₉₅ imidacloprid occurred across all field populations due to the involvement of P450. PIs of imidacloprid bait ranged 5–57 and 20–94 in populations under RI and IR, respectively. Field populations demonstrate different resistance profiles depending on the treatment regimes, and the resistance mechanisms involved influenced gel bait's effectiveness.

Biological invasions pose substantial threats to global biodiversity, agriculture, and ecological stability. Among these, intraspecific cryptic invasions, characterized by the spread of nonnative genotypes within a species, present unique challenges for detection and management. Despite the well-documented influence of invasive ants on ecosystems, instances of intraspecific cryptic ant invasions have rarely been documented. This study focused on the black cocoa ant, Dolichoderus thoracicus (Smith 1860), which has been increasingly reported as a pest inTaiwan over the past decade. In this study, we utilized a genome-wide approach employing multiplexed inter-simple sequence repeats genotyping by sequencing to identify single nucleotide polymorphisms across the D. thoracicus populations, elucidating the variations in the genetic population structure of the species in Taiwan. Our findings confirmed the occurrence of intraspecific cryptic invasions, demonstrating the coexistence of native and nonnative lineages, along with potential hybridization events between them. This study underscores the critical role of comprehensive genetic analysis in uncovering the complex dynamics of species invasions.

Tawny crazy ants (TCAs), Nylanderia fulva (Mayr) are an invasive species that develops extremely large populations that overrun landscapes. Control measures frequently rely on spraying contact insecticides, which often are inadequate. To provide insights for utilizing baits for their control, TCA foraging behavior was examined on liquid ant bait formulations that contained either fast-acting dinotefuran or slow-acting disodium octaborate tetrahydrate (DOT), and the impacts of these baits were assessed. Bayesian modeling of counts from time-lapse photography ofTCA feeding on the baits and a control of sucrose solution in the field revealed strong evidence of similar foraging intensities between the control and the DOT bait and less foraging intensity on the dinotefuran bait. TCA abundance on the dinotefuran bait peaked within 8 h, then diminished to smaller feeding bouts over the 3-day study. In contrast, foraging on the DOT and control remained consistently high before bait depletion. The impact of the fast and slow-acting baits in field plots were based onTCA nest sizes andTCA abundance on sausage lures. Bayesian modeling predictions revealed nest sizes declined over the 2 months with bait present while the control had large nests. Abundance on the lures in the dinotefuran plots declined from the start of the study, while with the slow-acting DOT bait, declines in abundance were not lower than the control plot until 30 days after baiting was initiated. Further refinements in baiting with liquid baits containing fast and slow acting active ingredients may provide fast and sustained control ofTCA.

The strategic use of refuge areas is a well-known method for delaying the development of pest resistance to Bacillus thuringiensis (Bt) crop. A lesser-known method to control against resistance development is sterile insect releases. In this article, an agent-based simulation model is used to test the effectiveness of combining the use of Bt sugarcane, refuge areas, and sterile insect releases as an integrated strategy against Eldana saccharinaWalker (Lepidoptera: Pyralidae) infestation and resistance development. Individual insects are modeled with their own genetic traits on a simulated sugarcane field that represents either Bt or refuge area.The model is applied to 2 hypothetical case studies. In the first experiment, resistance development and infestation dynamics in Bt sugarcane without refuge areas are considered using various sterile:wild sterile release ratios, and different release distributions. In the second experiment, the inclusion of a refuge area in Bt sugarcane is considered, using various sterile:wild releases ratios and different release distributions. A trade-off between sterile insect releases and the use of the refuge area was observed, and could, in some cases, work against each other.

Organophosphate (OP) insecticides have been used to control Grapholita molesta (Busck, 1916) in Brazil since 1990. However, the evolution of pest insecticide resistance and toxicological reassessments has led to the replacement of OPs with other chemical groups. This study evaluated the toxicity of the insecticides abamectin + cyantraniliprole (1.1 + 3.7 g a.i./100 L^–1), acetamiprid + etofenproxi (9.1 + 16.5 g a.i./100 L^–1), emamectin benzoate (0.5 g a.i./100 L^–1), Sophora flavescens (Fabales: Fabaceae) (22.8 g a.i./100 L^–1), phosmet (87.5 g a.i./100 L^–1), and indoxacarb (11.2 g a.i./100 L^–1) to eggs, larvae, and adults of G. molesta. Additionally, the residual activity of these insecticides in apple orchards was assessed, and the diagnostic concentration for resistance monitoring was estimated using LC₉₉ values (Lethal Concentration that causes 99% mortality in a susceptible population). In larval studies, all insecticides resulted in mortality rates of more than 90%. The insecticide acetamiprid + etofenproxi reduced larval hatching by 99%.This insecticide with phosmet and Sophora flavescens caused over 80% adult mortality and had a 14-day residual activity in apple orchards. The estimated LC₉₉ (µg. ml^–1) for resistance monitoring were 1.75 (indoxacarb), 6.45 (metaflumizone), 9.10 (acetamiprid + etofenproxi), 9.67 (Sophora flavescens), 36.13 (phosmet), and 45.61 (abamectin + cyantraniliprole).The insecticides evaluated have high toxicity for G. molesta, being new tools for integrated pest management and for insecticide resistance management in apple orchards.

Point mutations in the acetylcholinesterase-1 gene (ace-1) have been associated with resistance to OPs in many insects. However, the presence and function of ace-1 mutations associated with OP resistance in Helicoverpa armigera (Lepidoptera: Noctuidae), a significant lepidopteran pest damaging a wide range of crops, remain largely unexplored.This study investigated resistance to the OP insecticide phoxim in 12 field populations of H. armigera from northern China in 2022, revealing low levels of resistance (2.5- to 6.7-fold). Using an amplicon sequencing approach, we screened for ace-1 mutations in 13,874 moths collected from 114 populations collected between 2006 and 2022. We found 3 amino acid substitutions (A201S, G227E, and F290V) potentially related to OP resistance. The mean frequencies of A201S, G227E, and F290V mutations were 0.0032, 0.0001, and 0.0001, respectively.To assess these mutations' role in OP resistance, we expressed wild-type and mutant AChE1 proteins in Sf9 cells. Biochemical characterization revealed a 3.1-fold and 3.3-fold increase in the I₅₀ of chlorpyrifos-oxon for A201S and F290V mutants compared to the wild-type enzyme, correlating with a 2.9-fold and 2.7-fold decrease in the K_i value. No enzyme activity was observed in the G227E mutant, indicating that only A201S and F290V confer insensitivity to chlorpyrifos-oxon. Our study demonstrates that amplicon sequencing is an effective method for large-scale screening of resistance-associated point mutations in field populations of H. armigera and potentially other insect pests. It also identifies A201S and F290V in AChE1 as potential point mutations conferring OP resistance in field populations of H. armigera.

Graphical Abstract

We assessed the utility of a Bayesian analysis of dose–mortality curves using probit analysis. A Bayesian equivalent of a conventional single population probit analysis using Abbott's correction demonstrated the ability of the Bayesian model to recover parameters from generative data. We then developed a model that removed Abbott's correction and estimated natural survivorship as part of the overall model fitting process. Based on WAIC (information content) scores, this model was selected over the model using Abbott's corrected data in 196 out of 200 randomly generated datasets. This suggests that considerable information on control survivorship exists in response to treated doses in a bioassay, information that is partially removed when using Abbott's correction. Overdispersion in count data is common in ecological data, and a final model was developed that estimated overdispersion (kappa) as part of the model fitting process. When this model was compared to a model without overdispersion, it was selected as the best model in all 200 randomly generated datasets when kappa was low (5–20, high levels of overdispersion), while the 2 models performed equally well when kappa was large (500–2,000, low levels of overdispersion). The model with overdispersion was used to estimate parameters from bioassays of 10 populations of Helicoverpa zea (Lepidoptera: Noctuidae) exposed to Vip3a toxin, identifying 26 out of 45 pairwise comparisons that showed strong evidence of differences in LC₅₀ estimates, adjusted for multiple comparisons.

Tuta absoluta has developed resistance to many biological insecticides, causing substantial agricultural and economic losses annually. P450s have been the most extensively studied enzymes in the context of insecticide metabolism in insect pests, and the detoxification metabolism of P450s in T. absoluta against biological insecticides remains poorly understood. In T. absoluta, CYP304F1 was screened from the comparative transcriptome of 2 regional populations in Xinjiang, China. The objective of the present study was to characterize and analyze CYP304F1 of T. absoluta and explore its role in detoxification of spinetoram as well as the growth and development of T. absoluta. Following cloning and sequence analysis of the target gene, it was named CYP304F1. Expression levels of CYP304F1 were then determined after spinetoram exposure and across various developmental instars and tissues. Finally, dsCYP304F1 was synthesized and utilized to assess the effects of post-RNAi on larval spinetoram susceptibility, growth, and development. Sequence analysis revealed that CYP304F1 harbors conserved domains characteristic of P450 proteins, exhibiting high conservation within the Lepidoptera clade. Treatment with an LC₅₀ dose of spinetoram significantly upregulated CYP304F1 expression in T. absoluta larvae. Silencing CYP304F1 significantly enhanced larval susceptibility to spinetoram and prolonged leaf-mining duration and developmental time from the 2nd instar to 4th instar by 40% and 17.6%, respectively, compared to controls. And feeding on dsCYP304F1-treated leaves for 6 days resulted in 71% larval mortality. These results suggested that CYP304F1 played a crucial role in detoxification of spinetoram as well as in the growth and development of T. absoluta larvae.

Graphical Abstract

House flies, Musca domestica L. (Diptera: Muscidae), are commonplace pests in both urban and agricultural settings.The potential for house flies as vectors of many disease-causing organisms to humans and animals, coupled with their incessant nuisance behaviors toward these hosts has resulted in a desire to manage their populations. Although many house fly management tools are available, insecticide use continues to predominate as the preferred choice. One such option, insecticidal baits, is commercially available in a variety of active ingredients that encompass several modes of action.Though they can be effective, resistance to many of the active ingredients used in bait formulations has been documented.The primary pathway for resistance evolution to bait products likely has been selection at the targeted adult stage. However, exposure at the larval stage may occur when these products are scattered on substrates, contaminating sub-surface developmental areas and ultimately, playing a selective role as well. A study was conducted to assess the potential mortality effects of insecticidal bait products on house fly larval development when applied according to the manufacturer's recommended label rate. Adult house fly emergence was reduced by nearly 40% due to treatment, supporting the implication that bait-driven mortality during larval development may represent a previously unrecognized selection pathway contributing to resistance evolution against these products.

Solenopsis invicta Buren (Hymenoptera: Formicidae), also known as the red imported fire ant (RIFA), is currently established in many Southern and Central Californian regions. RIFA can be managed using various insecticides, but in recent decades, granular baits have become a standard and effective management tool. To improve and maintain effective RIFA management programs, researchers and pest control experts need to perform careful population monitoring before and after treatments. Despite the availability of various RIFA monitoring methods, many are challenging to perform and are extremely time-consuming. Counting mounds is an easier-to-perform method but may not be reliable in certain places and for detecting low-density populations. Other methods of field sampling and laboratory counting can be cumbersome, destructive, and highly time-consuming. In this article, we are providing research data on a new, fast, and nondestructive field technique for RIFA monitoring using density (ants/ml) measurements. These measurements can be converted into counts and eventually to indices. On average, the density of RIFAs inside our measuring cylinder was 130.8 ± 2.3 ants/ml (Mean ± S.E.). A strong positive and statistically significant correlation was found between the volume of RIFA workers and the number of ants (r = 0.92, P < 0.001).

Exploring the effects of different solvent extracts from Lepista nuda [(Bull. ex Fr.) Cooke] on the lifespan and reproductive capacity of Drosophila melanogaster (Diptera: Drosophilidae), the extracts of the fruiting body and mycelium of L. nuda were prepared using water, 75% ethanol, and petroleum ether, and the active components were identified. These extracts were then incorporated into culture media and administered to D. melanogaster. The impact of the extracts from different solvents on the life span and fertility, and the contents of ecdysone (20E), juvenile hormone (JH), and vitellogenin (Vg), as well as the effects of autophagy gene, 20E synthesis gene Halloween, 20E receptor gene ECR, JH methyltransferase gene JHAMT and Vg gene Yolk1 transcripts were analyzed. The extracts from the fruiting body and mycelium of L. nuda can reduce lifespan, a phenomenon associated with the varied expression of 15 compounds across 6 distinct groups. The average survival time of female fruit flies was lower than that of the male fruit flies. Fertility had also been significantly reduced, indicating a positive correlation between lifespan and fertility. In addition, with the extension of cultivation time, the content of 20E, JH, and Vg, as well as the transcripts of Halloween, ECR, JHAMT, and Yolk1 in the L. nuda fruiting body extract treatment group, all significantly decreased. Among the 3 solvent extracts, phenylalanine, citric acid, quinic acid, and punicalagin in the L. nuda aqueous extract exhibit the most potent collective toxicity toward fruit flies. The insecticidal properties of these compounds function by modulating autophagy and the expression of insect hormones.

Defensive metabolites and nutrient restriction of host plants are 2 major obstacles to the colonization of insect herbivores. The green peach aphid (GPA) Myzus persicae (Sulzer) broadly colonizes plants with diverse nutritional and defensive traits. However, how GPA adapts to nutritional and defensive traits within different plants remains largely unknown. To elucidate this, we first investigated the performances and transcriptomes of GPA feeding on cabbage Brassica oleracea and pepper Capsicum annuum.The green peach aphid had lower weight and fecundity when feeding on cabbage than on pepper. The transcriptomic analysis found 824 differentially expressed genes (DEGs), and 13 of the top 20 Kyoto Encyclopedia of Genes and Genomes pathways are related to nutrient metabolism, energy metabolism, and detoxification. Specifically, we found 160 DEGs associated with the metabolism of protein and amino acids, sugar and lipids, and xenobiotic substances, 86 upregulated in cabbage-fed GPA. Fourteen cathepsin B genes were strongly upregulated in cabbage-fed GPA, and were enriched in lysosome pathway and 2 dominated gene ontology terms peptidase activity and proteolysis. In addition, cabbage-fed GPA upregulated sugar and lipid digestion, while downregulated lipid biosynthesis processes. Furthermore, 55 metabolic detoxification enzyme genes were differentially expressed between GPA on 2 hosts, and detoxification enzyme activities of GPA indeed changed accordingly to the host.Then, we found that cabbage has lower amino acids nutrition quality for GPA compared to pepper. Our results suggested that adjustment of nitrogen nutrient metabolism, sugar and lipid metabolism, and metabolic detoxification in a host-specific manner play crucial roles in the adaptations of GPA to different host plants.

Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), is a pest in southern California citrus orchards because it protects honeydew-producing hemipteran pests from natural enemies. A major impediment to controlling L. humile is estimating ant densities in orchards. Ants use irrigation lines to travel across orchard floors to reach trees infested with hemipterans. However, for making ant control decisions, it is the number of ants in trees, not on pipes that is critical. Work completed here demonstrates that the number of ants counted on pipes is highly correlated with the number of ants counted on trunks. Densities of ants counted on trunks are correlated with trunk diameter, citrus variety, and time of year and time of day counts. Six regression models, linear regression, zero-inflated Poisson regression, and zero-inflated negative binomial regression models, and each of their mixed model extensions, indicated a strong positive relationship between ant counts on irrigation pipes and ant counts on tree trunks. Mean squared prediction error and 5-fold cross-validation analyses indicated that the best performing of these 6 models was the zero-inflated Poisson mixed regression model. A binary classification model developed using support vector machine learning for ant infestation severity levels, categorized as low (<100 ants counted in 1 min) or high (≥100 ants counted in minutes), predicted ant densities on trunks with 85% accuracy. These models can be used to estimate the number of ants on the trunks of citrus trees by using counts of ants made on irrigation pipes.

Graphical Abstract

(A) Argentine ants using a polyethylene irrigation pipe as a ‘highway’ to move across the floor of a commercial citrus orchard. (B) A trail of Argentine ants forming a column on the trunk of a citrus tree. (C) An infra-red sensor, attached to a polyethylene irrigation pipe, automates counts of ants on irrigation pipes.

Sequential sampling plans are employed for the rapid characterization of infestations to facilitate decision-making. This study aimed to (i) investigate the spatial distribution of Oligonychus punicae (Hirst) in grapevine crops, (ii) determine the most representative branch, leaf, and leaf region for monitoring, and (iii) develop a sequential sampling plan for decision-making to control O. punicae in the table grape varieties Arra 15, BRS Vitória, Cotton Candy, Sugar Crisp, and Timpson at different phenological stages. O. punicae distribution was analyzed across all varieties and developmental stages. Notably, O. punicae distribution varied among the tested varieties, with no consistent pattern observed in branches and leaves. However, a distinct distribution pattern was evident within leaves, with larger populations concentrated in the central regions. The lower and upper economic thresholds implement control measures varied according to the phenological stage, with the lower thresholds (economic threshold) set at 36% and the upper thresholds (economic injury level) at 40%. Consequently, a minimum of 3 and maximum of 20 plants were sampled. Overall, this study provides a robust approach to optimizing resource allocation and minimizing the environmental impact of O. punicae management.

Graphical Abstract

In Burkina Faso and many West African countries, Spermophagus niger (L.) is the main insect pest of Hibiscus sabdariffa seeds stored with considerable damage. Variations in bioclimatic conditions can lead to significant changes in the morphology and biology of populations of the same insect species, leading to strains that are morphologically and biologically different and that would react differently to a given control method. In this study, strains of S. niger from Niger (Niamey), Ghana (Navrongo), Benin (Parakou) and five localities in Burkina Faso (Diébougou, Banfora, Saaba, Mani, and Manga) are studied under controlled conditions (32 °C ± 0.1, 43% ± 1 r.h., L: D 12:12). The results showed that males from Niamey and Parakou lived longer, while females from Niamey and Diébougou had a statistically high longevity.

The larval survival rate of the Niamey strain was significantly lower than Manga, Parakou, and Navrongo. The Niamey strain recorded adults compared to the other strains. In terms of weight, the females and males from Banfora and Niamey were statistically heavier than other strains. At the end of the study, S. niger' strains showed different morphologies in terms of weight. Furthermore, adult longevity, larval survival rate, and emergence rate were strain dependent.

Thrips (Thysanoptera: Thripidae) can injure seedling cotton (Gossypium hirsutum L.), soybean (Glycine max (L.) Merr.), and peanut (Arachis hypogaea L.) crops in the southern United States. The planting window and timing of thrips infestations into these crops overlap in the region, but thrips preference for oviposition has not been investigated. We evaluated thrips preference for cotton, soybean, and peanut by counting eggs, immatures, and adults at the cotyledon to 4 true leaf stages. Peanut was significantly more attractive for oviposition than cotton and soybean. Oviposition in cotton was significantly higher in the cotyledons than the other leaves.The highest oviposition in soybeans also occurred in the cotyledons but differed only significantly from the fourth true leaf. In all crops, there was no significant difference among oviposition in the true leaves. The highest number of immatures were found on cotton, followed by peanut and then soybean, while adults were evenly distributed among crops. Our results suggest that while peanut is preferred for oviposition, this crop may not facilitate immature development and survival as effectively when compared with cotton. This study presents an initial examination of crop selection by thrips under field conditions and suggests peanut may be the preferred oviposition host.

Ceratapion basicorne (Illiger) (Coleoptera: Apionidae), a weevil native to Europe and western Asia, shows promise for enhancing the control of yellow starthistle (Centaurea solstitialis L.), an invasive annual forb in the western United States. However, a paucity of data on this biocontrol agent's environmental constraints has made it difficult to assess the suitability of potential release locations. Climate matching models were developed for C. basicorne to help identify areas of the western United States with similar climates to the source area of breeding colonies being used for releases (home location). The models used climate variables derived from daily estimates of minimum temperature, maximum temperature, precipitation, and soil moisture for a 30-yr period spanning 1991–2020 at 1 km² resolution. Of the areas where C. solstitialis is known to occur, the Central California Foothills, Eastern Cascades Foothills, Columbia Plateau, and mountainous parts of northcentral Utah had the most similar climates to the home location. Of these areas, the Eastern Cascades foothills in northeastern California and Wasatch Range in Utah occurred at a similar latitude as the home location, which may be important to consider if C. basicorne has photoperiodic diapause.The least similar climates occurred in wet coastal regions, high-elevation (cold) mountains, and hot deserts; however, C. solstitialis has not been detected in most of these areas.The development of process-based models for predicting the establishment of this agent will require a more detailed understanding of the agent's requirements for development and survival.