Corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), is a common herbivore that causes economic damage to agronomic and specialty crops across North America. The interannual abundance of H. zea is closely linked to climactic variables that influence overwintering survival, as well as within-season host plant availability that drives generational population increases. Although the abiotic and biotic drivers of H. zea populations have been well documented, prior temporal H. zea modeling studies have largely focused on mechanistic/simulation approaches, long term distribution characterization, or degree day-based phenology within the growing season. While these modeling approaches provide insight into H. zea population ecology, growers remain interested in approaches that forecast the interannual magnitude of moth flights which is a key knowledge gap limiting early warning before crops are planted. Our study used trap data from 48 site-by-year combinations distributed across North Carolina between 2008 and 2021 to forecast H. zea abundance in advance of the growing season. To do this, meteorological data from weather stations were combined with crop and soil data to create predictor variables for a random forest H. zea forecasting model. Overall model performance was strong (R2 = 0.92, RMSE = 350) and demonstrates a first step toward development of contemporary model-based forecasting tools that enable proactive approaches in support of integrated pest management plans. Similar methods could be applied at a larger spatial extent by leveraging national gridded climate and crop data paired with trap counts to expand forecasting models throughout the H. zea overwintering range.

Herbivorous insects utilize olfactory and visual cues to orient on suitable host plants, and such cues can be employed to facilitate insect monitoring. Lygus lineolaris Palisot de Beauvois is a polyphagous pest throughout North America. Monitoring this pest as it moves between crop and non-crop hosts remains challenging, and a lack of effective monitoring tools complicates management of this insect. In this study, we examined the electrophysiological and behavioral responses of L. lineolaris to the volatile emissions of 2 crop hosts: alfalfa and strawberry. Gas chromatography with electroantennographic detection was applied to identify antennally active compounds in headspace extracts of flowering host plants, before responses to individual compounds were examined in the field. Five compounds consistently elicited antennal depolarizations in adults of L. lineolaris and, of these, (±)-linalool increased the capture rate of L. lineolaris females in the field. Subsequent experiments examined the influence of visual cues and stereochemistry on capture rate, revealing that lures containing (±)-linalool and (S)-(+)-linalool significantly increased the capture rate of L. lineolaris females compared with traps baited with (R)-(-)-linalool and controls, indicating that L. lineolaris is attracted to (S)-(+)-linalool. While lures increased capture on red traps, this was not the case for white traps, emphasizing the importance of visual cues in the movements and monitoring of L. lineolaris. This study demonstrates that L. lineolaris is attracted to (S)-(+)-linalool in the field, and that attraction depends on trap color. This knowledge is expected to improve monitoring strategies for L. lineolaris in agricultural systems.

Insect pollinators are essential for natural ecosystems. Without pollination, native plants are less likely to be able to persist. As natural ecosystems have become more fragmented and degraded, interest in their restoration and preservation has increased. Understanding the roles that individual plant and pollinator species play in an ecosystem can assist with these tasks. One way to examine the ecological drivers for patterns of pollination is through module analysis. The Palouse Prairie is a fragmented native prairie that supports high plant and insect diversity and has experienced severe habitat loss. Bees were collected on native plants in prairie fragments in 2022 and 2023 to construct a plant-pollinator network. From this network, modules were computed and analyzed. This network contained 10 modules representing multiple different ecological patterns, including modules grouped by morphological, taxonomic, and phenological similarities. These modules also identified plant-pollinator pairs with specialized relationships. The network was then analyzed to identify plant and insect members that play structural roles in the network. Understanding the patterns of interactions represented in the modules and the network structure may allow for better conservation and restoration of this imperiled ecosystem.

Planting native flora is a popular conservation strategy for pollinators. When searching for native plants, consumers may encounter cultivars of native plants, which can have different phenotypic traits than plants found in wild populations ("wild-type native plants"). Previous research evaluating pollinator visitation to wild-type native plants and native cultivars has yielded mixed results, in terms of whether their visitation rates are similar or distinct. We established a garden experiment in Corvallis, Oregon, to examine pollinator visitation and utilization of Pacific Northwest native plant species and cultivars. Over 3 years, we collected and observed bees (Hymenoptera: Apoidea), butterflies (Lepidoptera: Papilionoidea), and syrphid flies (Diptera: Syrphidae) to understand (i) if plant pairs had different visitation rates, (ii) whether any pollinators were associated with differential visitation, and (iii) if specialist taxa preferred wild types over cultivars. Pollinator visitation rates varied by plant and pollinator groupings, but in comparisons between native plant and cultivar pairs, native plants were preferred 37.2% of the time (n = 29 comparisons), cultivars 7.7% of the time (n = 6), and there was no difference in 55.1% of comparisons (n = 43). Our pollinator community data found native plants had greater observed total pollinator richness (except for 1 tie) and bee richness than cultivars, though predicted richness varied. Specialist bees were collected more often from wild types. Cultivars with high visitation rates were minimally developed selections, as opposed to interspecific hybrids. Our results join a growing body of literature in suggesting wild-type native and minimally developed plants should be emphasized for supporting pollinator fauna.

Wild bee communities are the target of various conservation and ecological restoration programs. Strategic conservation can influence bee communities visiting fields and help mitigate pollinator limitations in fruit production. However, planning compatible conservation strategies and gauging their effectiveness requires understanding how local communities vary across space and time in crops and adjacent semi-natural areas. Here, we assessed the spatiotemporal changes in the composition of wild bee communities in blueberry fields and adjacent forests. In partnership with commercial farms in southeast Georgia, USA, we deployed blue vane traps at the interior and edge of blueberry fields and within adjacent forests of 8 fields, from March to October over 2 yr. We identified 72 wild bee species across 26 genera. The most common were Melissodes communis (Cresson, Hymenoptera: Apidae), Bombus bimaculatus (Cresson, Apidae), Melissodes bimaculatus (Lepeletier), Ceratina floridana (Mitchell, Apidae), Lasioglossum pectorale (Smith, Halictidae), and Lasioglossum nymphale (Smith), which accounted for nearly 60% of the wild bees caught. Bee diversity and richness fluctuated over time, with peaks in all 3 habitat types occurring after the blueberry blooming. Bee abundance in the adjacent forest was relatively constant throughout the season, while in the field interior and edge assemblages, abundance peaked between May and June. We observed dissimilarity in species composition related to month and field location. This difference was explained by fluctuation in the identity and relative abundance of the most abundant species. Together, our study advances foundational knowledge of wild bee community dynamics and species identity in blueberry fields which will help inform and prioritize conservation practices.

Understanding and optimizing rearing conditions for dragonfly larvae is crucial for ecological research and conservation efforts, yet optimal rearing conditions and general rearing practices are lacking. In this study, we investigated the effect of temperature, amount of oxygen in water, presence of (artificial) plants, and age of eggs on hatchability, survival, and development of dragonfly larvae using the model species Sympetrum striolatum. We conducted three independent experiments and assessed variability between egg clutches of individual females, as well as the occurrence of cannibalism among larvae. Our results showed that egg hatchability varied significantly between individual females and was negatively affected by egg aging and the presence of artificial plants. Larval survival was negatively affected by water temperatures above 24°C, the presence of artificial plants, and egg aging, and positively affected by high feeding frequency, in certain instars. Notably, cannibalism was observed among later instar larvae, especially under higher density conditions. Based on these findings, we provide practical recommendations for optimizing dragonfly larvae rearing protocols, emphasizing the importance of maintaining optimal temperature, appropriate feeding regimes, and managing larval density to reduce cannibalism. This study offers experimental, evidence-based guidelines for dragonfly larvae rearing, contributing to improved research methodologies and conservation efforts.

The non-native wood-boring and symbiotic fungus-culturing Xylosandrus germanus (Blandford) was first reported in New York apple orchards in 2013. Trapping surveys have been conducted annually since to assist growers in timely applications of preventative control measures. In 2021, a similar-looking introduced species, Anisandrus maiche (Kurentsov), was identified in traps in west central New York. Anisandrus maiche was first recorded in 2005 in Pennsylvania but its history in New York was unclear due to potential misidentification. We collected and identified ambrosia beetles using ethanol-baited bottle traps in 2022 and 2023 in New York at 2 commercial apple orchards near Lake Ontario and 2 cider apple orchards in the lower Finger Lakes district. Traps were placed in a forest interior, the forest edge, and the orchard edge at each site. Xylosandrus germanus was trapped from mid-April into early October; it was abundant in the Lake Ontario region but less so in the Finger Lakes. In contrast, counts of A. maiche were very high in the Finger Lakes but extremely low near Lake Ontario. It was trapped from late-May to mid-September. Most other bark and ambrosia beetle species were uncommon. Captures of X. germanus and A. maiche were generally highest in the forest interior and declined toward the orchard edge, but each species was usually present in traps across habitats at the same time. Thus, the practice of trapping at forest edges should continue. Both species can potentially infest stressed trees, including in orchards, throughout the growing season.

A new population of the Asian longhorned beetle (Anoplophora glabripennis Motschulsky), an invasive species in North America since 1996, was discovered in Charleston County, South Carolina, in 2020. This population is the furthest south Asian longhorned beetle has established in North America. Previous models only estimate development time at this latitude; as such, we examined Asian longhorned beetle phenology in this novel climate. Over 24 consecutive months, we collected 153 eggs, 878 larvae, 37 pupae, and 1 unemerged adult (1,009 total specimens) from the federal quarantine zone in South Carolina and used larval head capsule width to determine development rate and voltinism. The presence of Asian longhorned beetle adults was determined via visual field observations. Asian longhorned beetle in South Carolina appears to have a synchronous univoltine life cycle, in contrast to populations in the northern United States and Canada that typically develop in 2-3 yr. This information will be useful for future model development to determine Asian longhorned beetle life cycles, for implementing novel management methods, and will aid in predictions to benefit visual survey efficacy.

Understanding the movement and distribution patterns of insects is crucial for developing effective stored grain management protocols. This research investigates 3-dimensional movement and distribution of Tribolium castaneum (Herbst) and Cryptolestes ferrugineus (Stephens) separately at different temperatures (5, 10, 20, and 30°C) and for different movement periods (1, 2, 3, and 24 h) in stored wheat with a uniform moisture content of 14.5% (wet basis). The experiments were conducted in a wooden container with internal dimensions of 0.7 × 0.7 × 0.7 m. The wheat was filled into 343 mesh cubes (referred to as cubes), each measuring 0.1 × 0.1 × 0.1 m, arranged in 7 layers after being loaded into the container. One hundred insects were introduced into the center cube (the center of the container) at the start of each experiment. After the desired movement period, the cubes were removed in less than 45 min from the wooden container. The wheat in each cube was wrapped in labeled plastic bags, sieved, and the insects were recovered and counted. Results indicated that both species exhibited movement speeds > 7.2 m/d in vertical and horizontal directions at higher temperatures (20 and 30°C). At lower temperatures (5 and 10°C), their vertical speed was higher than their horizontal speed. Tribolium castaneum ceased movement at 5°C, whereas ~13% of C. ferrugineus adults continued to move at this temperature. The drift effect and geotaxis influenced the movement and distribution of both species in the vertical direction, while their horizontal movement followed a diffusion pattern.

Histia rhodope (Cramer) (Lepidoptera: Zygaenidae) is one of the most destructive defoliating pests of the landscape tree Bischofia polycarpa (Levl.) S in China and other Southeast Asian regions, posing a critical threat to urban landscapes and their ecological benefits. This pest has shown a trend of northward range shift in recent years in China, making it urgent to understand its potential distribution. This study investigated the cold tolerance of overwintering H. rhodope larvae from October 2022 to March 2023 and estimated their overwintering potential in China. The results showed that the supercooling points (SCP) differed significantly across months. The SCP tended to decrease as the ambient temperature dropped until January, after which it gradually increased until the end of winter. The highest monthly mean SCP was -7.5 ± 2.22°C (October 2022), while the lowest monthly mean SCP was -15.09 ± 2.61°C (January 2023). The mortality rate increased with longer exposure times and lower exposure temperatures but decreased as winter progressed. Moreover, 50% and 90% lethal temperature (Ltemp50 and Ltemp90) exhibited a similar trend, decreasing to a minimum in January 2023, which indicates increased cold tolerance during the colder months. Using Ltemp90 in January as the isotherm for its northern limit indicated that H. rhodope may be limited by low temperatures along the 40°N latitude. These results provide a basis for predicting the dispersal potential and possible geographic range of this pest in China.

In recent years, the damage caused by thrips has become a key factor impacting the winter and spring production of fruits and vegetables in Hainan Province, China. This study aimed to elucidate the effects of different pupation environments on pupal development and eclosion of chilli thrips (Scirtothrips dorsalis Hood) by analyzing pupal development and eclosion of chilli thrips in an indoor environment with simulated natural soils and water content. Soil type, soil water content, and temperature substantially affected the eclosion of chilli thrips during the pupal stage. Both a low soil water content of 1% and a high soil water content of 15% were not conducive to the pupation and eclosion of chilli thrips. Moreover, the results indicated an interaction between soil type and soil water and temperature and soil water content, affecting the eclosion of chilli thrips. Chilli thrips not only pupated in soil but also completed pupation and eclosion in other soil-less environments, such as tender mango leaves, stalks, plastic mulch, and weed fabric. This study suggests that in addition to adopting pest control measures that target the canopy layer of crops, appropriate measures such as increasing soil water content can also be implemented in the ground layer to enhance the overall effectiveness of pest control.

Stink bug species emerged as major insect pests of cotton in the mid-southern United States following the eradication of the boll weevil and the introduction of genetically modified Bt cotton for lepidopteran pests. Considering the limited number of chemical classes available for insect control, further insights into other chemistries are necessary to inform management strategies with the overall goal of establishing and maintaining the most cost efficient and efficacious control programs for stink bugs in Alabama. The insect growth regulator, novaluron, has shown control of tarnished plant bugs, but little research has been done on its effect in stink bugs. The objective of our study is to evaluate the effects of novaluron, in a laboratory setting, on adult fecundity, nymphal mortality, and yield and damage in the field. We hypothesized that novaluron would have a direct effect on mortality in nymphs and could decrease fecundity in adult stink bugs. Although the effect on fecundity was counter to our hypothesis, this study shows effective control of nymphs in our model insect, the southern green stink bug, Nezara viridula (Hemiptera: Pentatomidae). Future evaluation of proper timing of novaluron applications could make this a valuable tool for residual control of stink bugs in cotton.

Joshua Tree National Park (JOTR) in southern California offers a unique opportunity to explore insect biodiversity across 2 distinct desert ecosystems: the lower-elevation Sonoran Desert and the higher-elevation Mojave Desert. In these harsh environments, many blow flies (Diptera: Calliphoridae) serve as important decomposers, feeding on animal waste and decomposing tissue. Some blow fly species, notably non-native species, are associated with human activity, which underscores the need to study their communities in JOTR, where annual visitation has reached 3 million. This study investigated the community composition of blow flies across the park and assessed the impact of visitor activity on blow fly communities in JOTR. Sampling from 2021 to 2023 using traps baited with squid carcasses revealed higher blow fly diversity in the Mojave Desert relative to the Sonoran Desert, in contrast to previous insect and vegetation surveys within the park. Across the park, blow fly community composition (i.e., β-diversity) differed by season. Blow fly abundance, richness, and diversity were similar between low- and high-visitor activity sites. However, more non-native species were collected in areas of low visitor activity, suggesting regular waste removal practices in high-visitation sites might limit their ability to complete development as secondary colonizers. This study is the first to characterize blow fly communities in Joshua Tree National Park. These findings demonstrate that blow fly communities reflect previously established park boundaries and underscore the importance of waste management practices in reducing the spread of non-native species throughout the park.

Climate change is expected to lead to rising winter temperatures in temperate zones, coinciding with a decrease in winter snow cover. Insects adapted to winter conditions in the temperate zone might be exposed to changing winter conditions and higher temperature fluctuations, which can affect diapause and mortality. We studied the effects of climate change on Chrysolina polita, a temperate zone species overwintering as an adult in the shallow surface of the soil. We tested the effects of increased and fluctuating temperature on the mortality and body composition of the beetles in a laboratory environment, as well as the effects of snow cover removal on the mortality and body mass in field conditions. We found that in the laboratory study, a 2 °C increase in mean temperature increased mortality and resulted in increased lipid consumption, whereas temperature fluctuation caused desiccation of the beetles but did not affect mortality compared to the control condition. In the field study, the snow removal caused the mean soil temperature to decrease by 3 °C and fluctuate (ranging from -26.4 to 2.5 °C compared to a range of -1.7 to 0.5 °C in the control), yet these differences did not affect beetle mortality or body mass. We conclude that C. polita exhibits greater resistance to cold temperatures than to higher temperatures during diapause. Therefore, the rising temperatures associated with climate change can pose challenges for overwintering.

Microplastics (MPs) are a growing problem worldwide. Soils are long-term storage sinks of MPs because of the many pathways they enter the soil and their long degradation period. Knowing how MPs influence soil organisms, the effects of organisms on the fate of MPs, and what this means for soil additions, losses, transformations, and translocations is paramount. MPs in soil could impede the breakdown of organic matter by adult darkling beetles. We set up an experiment to test this hypothesis by adding finely ground scrap tire rubber to organic soil and a small population of adult darkling beetles (Zophobas morio, Fabricius 1776, Coleoptera: Tenebrionidae). The beetles are omnivores that accelerate the breakdown of soil organic matter when feeding on soil detritus. As a control, we released beetles into organic soil with no MPs. We also surveyed published manuscripts on the effects of MPs on insects, decomposers, and decomposition in soil, providing a reference frame for our findings. Darkling beetles ate, fragmented, and humidified the soil mixture, enhancing microbial decomposition. All treatments lost weight over the experiment period, with the control losing 10%, significantly more than the other treatments (an average loss of 5%). Higher concentrations of microplastics in soils led to lower reductions in soil mass through decomposition. These findings suggest that MPs impede detritivores from breaking down soil organic matter. Even so, only a handful of studies evaluated the effects of tire particles on soils and detritivores in the literature survey. Still, these particles are among the largest sources of MPs on land.

Facultative diapause is a life history trait that allows insects to undergo continuous development when conditions are favorable or to enter diapause when they are not. Insect voltinism can have an impact on the success of a weed-biological control agent because additional generations can increase agent population growth and reduce late-season recovery in the target weed. The most common factors that cue diapause are photoperiod and temperature; however, the role of nutrition is increasingly being recognized. We conducted a laboratory experiment to examine the effects of photoperiod and foliage age on diapause induction, pupal weight, and pupal development time in Hypena opulenta (Christoph) (Lepidoptera: Erebidae), a biological control agent for invasive swallow-worts in North America. A factorial experimental design was employed whereby H. opulenta was reared at long (16:8 h light:dark) and short (12:12 h) photoperiods on young and old swallow-wort foliage (Vincetoxicum rossicum Kleopow) Barbar. (Apocynaceae). Photoperiod was the only factor that affected diapause induction in H. opulenta. While foliage age did not affect diapause induction, it did affect pupal weight and pupal development time, with older foliage resulting in lower pupal weight and extended pupal phase. In field conditions, these impacts could affect pupal mortality through reduced winter preparedness and increased exposure to predators. These results support H. opulenta voltinism models based on photoperiods and indicate that the tendency of captive-reared H. opulenta to enter diapause after 2 or 3 generations, even in the absence of short photoperiods, is not a result of changing foliage age.

The growing expansion of eucalyptus plantations in Brazil and the impact of exotic pests, such as Gonipterus platensis, demand effective, and sustainable biological control strategies. The aim of this study was to assess the pathogenicity of 10 Bacillus thuringiensis (Bt) isolates to neonate Gonipterus platensis larvae, commonly known as the eucalyptus weevil (Coleoptera: Curculionidae) with the specific focus of evaluating their potential to manage this pest while preserving its egg parasitoid, Anaphes nitens. To achieve this, the genomic DNA of the 10 Bt isolates was extracted using the thermal lysis method for molecular characterization of their Cry and Vip proteins. Neonate G. platensis larvae were subjected to bioassays with each isolate, at a concentration of 1 × 109 spores/ml, was applied on 10 larvae per replication (3 replications). The concentration and lethal time to kill 50% of the larvae were determined for the most effective isolates. The Bt isolates 107 and 178 isolates even at concentrations 10× lower than those recommended for commercial Bacillus thuringiensis var. tenebrionis (Btt) formulations against Coleoptera pests, achieved 100% mortality of G. platensis larvae. These isolates, with coleopteran-specific genes, caused high mortality of neonate Gonipterus platensis larvae. This indicates their potential for the biological control of this pest and maybe of other Coleoptera pests. Their use poses minimal risk to non-target organisms such as the egg parasitoid A. nitens and indicates a promising avenue for integrated pest management strategies with effective pest control while preserving the ecological balance.

The microbial composition of insect guts is typically influenced by the type of food consumed, and conversely, these microbes influence the food habits of insects. Western flower thrips (WFT; Frankliniella occidentalis) is an invasive pest with a wide range of hosts, including vegetables and horticultural crops. To elucidate variations in gut bacteria among WFT feeding on rose (Rosa rugosa) flowers (FF), kidney bean (Phaseolus vulgaris) pods (PF), and kidney bean leaves (LF), we collected adult guts and extracted DNA for 16S ribosomal RNA gene sequencing of microbial communities. The results revealed that the FF population had the highest number of annotations. Alpha diversity analysis revealed that the Chao and Ace indexes were the greatest in the PF population, indicating a higher abundance of gut bacteria. Moreover, the Simpson index was the highest in the FF population, indicating that gut bacterial diversity was the highest in the FF population. Comparison of species composition demonstrated that Proteobacteria dominated all 3 populations at the phylum level, with Actinobacteria being the subdominant phylum. At the genus level, Stenotrophomonas was the dominant bacteria in the PF and LF populations, whereas Rosenbergiella was dominant in the FF population. KEGG pathway annotation predicted that the gut bacteria of adult WFT were mainly involved in carbohydrate and amino acid metabolism. Our results revealed that the diversity and composition of WFT gut microbiota are influenced by diet, offering evidence for future studies on the ecological adaptability of WFT and the mechanisms underlying the interaction between gut microbiota and host.

The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), is a polyphagous woodboring beetle that infests and damages hardwood host trees in Asia, Europe, and North America. Native to China and the Korean peninsula, ALB is invasive in both North America and Europe. Due to the large environmental and economic impacts associated with ALB, much effort has been placed on its management and eradication from invaded areas. Eradication programs consist of visual surveys, regulatory quarantines, host removal, public outreach and education, and in some cases, insecticides. Host removal is effective but is laborious and costly, and while insecticides have been useful as a component of some eradication programs, they can be expensive, ineffective, and environmentally detrimental. Thus, several arthropod biological control agents (BCAs) have been evaluated which could support a more environmentally friendly management strategy to supplement traditional ALB management tactics. Here, we review the biological control strategy for ALB, including the exploration within the native and invaded ranges of the pest, to find potential arthropod BCAs. We discuss the ecological premise behind the method as well as the potential for its success, and we identify knowledge gaps and future considerations for the enactment of this method. While biological control shows promise, care will be needed in utilizing this method, and further research must explore the success of BCAs in field settings.

Imidacloprid is a widely used insecticide for controlling piercing-sucking pests. However, its impact on nontarget insects must not be ignored. In this study, we assessed the effects of sublethal dose of imidacloprid on Sclerodermus alternatusi (Hymenoptera: Bethylidae), which is an important predator of many pests. The data indicate that imidacloprid at LD10 (0.1468 ng active ingredient per insect) and LD30 (0.2376 ng active ingredient per insect) significantly reduced the longevity and fecundity of the F0 generation of S. alternatusi. However, the adult female longevity of the F1 generation of the LD10 dose group showed a significant increase, and the LD30 dose group showed a nonsignificant increase. The study found that as the imidacloprid dose increased, the intrinsic rate of increase (r) decreased, while the mean generation time (T) increased. The imidacloprid groups also showed a decrease in age-stage specific survival rate (Sxj) and age-specific survival rate (lx). However, the female age-specific survival rate (fx4) showed an increasing and then decreasing trend for all treatments. The study found that imidacloprid had an impact on the longevity of S. alternatusi in the F0 generation and extended the mean generation time (T) in the F1 generation. However, it had negative effects on population growth parameters. These findings can be used as a basis for developing integrated pest management strategies.