Honey bees (Apis mellifera) are important pollinators for natural and cultivated species. Due to their high sensitivity to stressors, they are also valuable indicators of environmental changes and agricultural management practices. In this study, we compared the performance and incidence of pesticides over sentinel hives within forest remnants with those within linear forest fragments (LFF) surrounded by soybean fields under conventional management. Sentinel hives in LFF showed some signs of deterioration, such as colony collapse, low numbers of brood frames, and pesticide occurrences, but honey production and the number of adult bees were similar to hives in the forest. Soybean pollen was scarce in honey and absent in bee bread, suggesting that bees may be relying more on wild plant species. We detected 5 pesticides (azoxystrobin, carbendazim, chlorpyrifos, imidacloprid, and coumaphos) in hives both at forests and LFF in pollen, bee bodies, and wax; pesticides in honey were detected in old sentinel hives (2 yr of exposition to agricultural conventional management). Only 2 of the 5 pesticides were applied in one of the farms under study, highlighting the importance of considering landscape-scale agricultural management. Our results indicate that conventional agriculture of soybean/maize primarily affected the performance of beehives, and pesticides were detected in honey only after long exposure to hives. Beekeeping in soybean fields in the Chaco could be feasible if cautions were followed, such as the conservation of forest fragments and key plant species, appropriate pesticide schedules, coordinated applications among farms, and linear forest remnants improvements.

Tomato yellow leaf curl virus (TYLCV) and Tomato chlorosis virus (ToCV) are plant-infecting viruses that are mainly transmitted by Bemisia tabaci Gennadius. In addition to their significant individual impacts on agricultural production, TYLCV and ToCV co-infections are increasingly common and can cause devastating losses in tomato and other crops. Cathepsins, the main proteases in lysosomes, affect both immune responses and the digestion of plant proteins and may help mediate Bemisia-virus-plant interactions. We conducted research exploring the role of cathepsin in the interaction between B. tabaci MED and the plant viruses TYLCV and ToCV, both singly and in combination, on tomato. Levels of cathepsin F increased sharply in B. tabaci MED after feeding on TYLCV-infected, ToCV-infected, and co-infected plants and remained elevated for several days after feeding cessation. In all cases, levels were higher in co-infected B. tabaci MED than in singly infected individuals. Viral loads of each virus were also higher in co- versus singly infected B. tabaci MED, suggesting a synergistic relationship between TYLCV and ToCV. We next studied how dosing B. tabaci MED with a cathepsin inhibitor, inducer, or control affected viral acquisition, retention, and transmission. Viral acquisition and retention were lower in B. tabaci MED treated with cathepsin inducer than in controls; B. tabaci MED treated with cathepsin inhibitor had higher rates of viral acquisition and retention. Viral transmission was highest in the inhibitor treatment and lowest in the inducer treatment. Our results provide more opportunities for the design of novel control strategies to manage insect vectors and their transmitted viruses.

Marmalada hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae), is a cosmopolitan fly species providing pest control and pollination services. As wheat aphids cause significant losses to global wheat production, a systematic evaluation of the predatory potential and biocontrol service functions of E. balteatus in wheat ecosystems was undertaken.The daily maximum prey consumption of third instar E. balteatus on the adult of Rhopalosiphum padi Linnaeus, Schizaphis graminum Rondani, and Sitobion miscanthiTakahashi (Hemiptera: Aphididae) were 250, 500, and 100 individuals/third instar larvae, respectively. The S. graminum population decline rates in cages after release of the third instars at ratios of 1:100 and 1:200 were 100% and 94.17%, respectively, 72-h after exposure. Feeding assays involving R. padi, S. graminum, and S. miscanthi showed a DNA detectability half-life of 4.17, 6.44, and 4.83 h, respectively, in third instar larvae of E. balteatus. Using multiplex polymerase chain reaction-based gut content analysis to detect prey DNA remains, we confirmed that E. balteatus larvae preyed upon R. padi, S. graminum, S. miscanthi, and Metopolophium dirhodumWalker (Hemiptera: Aphididae) in the field experiments during 2022 to 2024. A significant positive correlation was also found between corrected prey detection rate and aphid population dynamics. These results provide an entry point for understanding the ecological service function of E. balteatus and developing the biological control strategy of the wheat aphid management.

Intraguild predation (IGP) is a crucial ecological interaction that influences the dynamics of natural enemies and affects the effectiveness of biological control. Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), an invasive predator, significantly impacts native predators through IGP in certain countries. Pyemotes zhonghuajia (Yu, Zhang & He) (Prostigmata: Pyemotidae), a small ectoparasitoid, parasitizes various pests from the orders Lepidoptera, Coleoptera, and Hemiptera. Although both natural enemies are essential in controlling pests like Neotoxoptera formosana (Takahashi) (Hemiptera: Aphididae), their interactions and effects on pest management remain poorly understood.The study investigates the functional response of H. axyridis to N. formosana, the lethal ability of P. zhonghuajia against N. formosana, and how intraguild interactions affect the mortality rates of both N. formosana and H. axyridis when exposed to P. zhonghuajia. Our findings revealed that H. axyridis exhibited a Holling type II functional response to N. formosana, with female adults being the most effective predators. Pyemotes zhonghuajia demonstrated significant lethality against N. formosana, particularly at higher mite densities. However, the presence of P. zhonghuajia also increased the mortality rate of H. axyridis, highlighting a parasitism-driven intraguild interaction in which the mite dominates the predator. These results challenge conventional views of predator–parasitoid dynamics and highlight the complexity of interactions among natural enemies in pest control systems.

Increasing costs and limited supply of fishmeal make fish feed more expensive. Pupa of the silkworm (Bombyx mori L.), a byproduct of the sericulture industry is a cheap and sustainable alternative to fish meal. This study aimed to examine the impact of replacing fish meal with silkworm pupae meal on the growth performance and health profile of Gift Tilapia fingerlings (Oreochromis niloticus). Gift Tilapia fingerlings (3.38 ± 0.23 g) were divided into 4 groups (n = 60 in each group). These fish were reared for 10 wk and fed at the rate of 4% body weight daily at 10 am and 3 pm. The basal standard diet was given to the control. The other 3 experimental diets were prepared with 10% (SWP10), 20% (SWP20) and 40% (SWP40) replacement of fish meal with silkworm pupae meal. The results showed that the values of weight gain, feed efficiency ratio and organosomatic indices were significantly higher (P < 0.05) in the SWP40 group as compared to all other groups. The values of red blood cells, white blood cells, hematocrit, mean corpuscular volume, and hemoglobin concentration were also significantly improved in the SWP40 group. Whole-body crude protein differed non-significantly (P > 0.05) in all the study groups. The fat content was significantly higher in the SWP20 group. It can be concluded that silkworm pupae are a suitable source of protein to be substituted in the feeds of Gift Tilapia replacing 10% to 40% of fish meal for enhanced health profile and promising growth.

The GHA strain of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) is known to establish symbiotic relationships with some plant species. The present study was developed to determine whether the foliar application of B. bassiana-GHA and B. bassiana ANT-03, another commercial B. bassiana, results in the successful colonization of cotton, Gossypium hirsutum L., and examine whether the endophyte can influence the survivorship and feeding damage by the corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae). Using polymerase chain reaction, colonization success by B. bassiana-GHA, 3, 7, 14, and 21 days after inoculation was estimated at 83.3%, 100%, 91.7%, and 83.3%, respectively. The colonization success based on the mycelial outgrowth method was 41.7%, 66.7%, 58.3%, and 50%, 3, 7, 14, and 21 days after inoculation, respectively. Beauveria bassiana ANT-03 did not colonize cotton. Corn earworms preferred untreated plants over the neonicotinoid and B. bassiana-GHA treatments. The B. bassiana ANT-03-treated plants and controls were not distinguished from one another by the corn earworms.The corn earworm survivorship was higher on the control plants, compared to plants treated with B. bassiana ANT-03, B. bassiana-GHA, and the neonicotinoid insecticide.The neonicotinoid insecticide, B. bassiana-GHA, and B. bassiana ANT-03 reduced corn earworm damage compared to the untreated controls. Our results demonstrated the potential for B. bassiana-GHA to be used as a biological control agent against H. zea in cotton.

Eucryptorrhynchus scrobiculatus (Motschulsky) and E. brandti (Harold) are 2 serious pests inflicting damage on Ailanthus altissima (Mill.) Swingle. In the field, these species exhibit aggregation behavior.We hypothesized that this behavior facilitated the contact and horizontal transfer of Metarhizium anisopliae (Metschn.) Sorokin in weevil species. Little or no mortality in both E. scrobiculatus and E. brandti adult individuals exposed to low concentrations M. anisopliae (1 × 10⁵, 1 × 10⁶ conidia/ml). A mortality rate of 100% was observed in both E. scrobiculatus and E. brandti adults after 3 and 5 d of treatment with M. anisopliae at concentrations of 1 × 10⁹ and 1 × 10⁸ conidia/ml.The aggregation behavior of E. scrobiculatus and E. brandti adults was unaffected by M. anisopliae. In the transfer test of M. anisopliae, the mortality rate of recipients mixed with donors treated with M. anisopliae conidia was significantly higher compared to untreated donors and control recipients in laboratory and field experiments. Furthermore, the mortality of secondary recipients in both E. scrobiculatus and E. brandti was significantly higher than that of the control group.The findings suggested that horizontal transfer of M. anisopliae occurred in both species, which was further supported by microscopy observation and the activity of immune-related enzymes in the donor, recipient, and secondary recipient. Our findings demonstrated a specific method for improving pest control by combining aggregation behavior with the use of biopesticides, thereby enhancing the understanding of biological management strategies.

Graphical Abstract

The adults were transferred to another Petri dish as donors and were mixed with untreated adults after being treated with M. anisopliae SW23, or purified water (control). The untreated adults who received the mixing treatment were frozen to death, and then they were transferred to a new Petri dish and mixed with other untreated adults.The adults were then used as secondary recipients in the experiments.The different colored dots represent E. scrobiculatus or E. brandti under different treatments in the figure.

Conservation biological control in agriculture primarily relies on avoiding pesticides that may harm key natural enemies. In temperate tree fruit crops, the European earwig, Forficula auricularia (L.) has only recently become appreciated as an important predator of economic pests, particularly woolly aphids and pear psylla. Therefore, the non-target effects of orchard pesticides on earwigs are largely understudied. This is particularly true for herbicides, which earwigs are likely to be exposed to due to their foraging behavior moving between the canopy and the ground cover. We tested residues of formulated pesticides (8 insecticides and 7 herbicides) commonly used in tree fruit crops for lethal and sublethal (movement, predation rate) effects on adult female earwigs.Two herbicides, paraquat and glufosinate, and one insecticide, spinetoram, were acutely toxic to earwigs within 72 h. No tested pesticides altered earwigs' movement or resting behavior compared to the control.The insecticides spinosad and cyantraniliprole and the herbicides 2,4-D, glufosinate, halosulfuron, rimsulfuron, and oxyfluorfen reduced earwig predation on green peach aphids. Therefore, these pesticides may reduce earwig predation on pests in orchards. Our results suggest that some pesticides are of greater risk, and thus, should be carefully considered or better timed when used in tree fruit orchards where earwigs are considered for conservation or augmentative biological control.

The European earwig, Forficula auricularia L. (sensu lato), has a dual role in temperate tree fruit crops—a pest of stone fruit and a predator of key pests in pome fruit. Some growers trap earwigs in crops where they are pests, subsequently releasing them in pome fruit as an augmentative biological control strategy. Effective earwig monitoring and trapping are critical for understanding their biological control potential in orchards. Traps made of rolled, corrugated cardboard have long been used for earwig monitoring; however, no standardized studies have investigated improvements to them. In a series of trials, we explore options to improve traps by testing different trap materials, sizes, positioning on the tree, and time in the field, in addition to the lures and baits. We found that cardboard traps had higher earwig catch than black or translucent plastic traps. There were diminishing returns in earwig capture for increased trap length, plateauing at ∼30 cm. Traps placed on the main trunk captured more earwigs than traps on the base or near the end of branches. Lures and baits mostly did not increase trap efficacy, except fish sauce which inconsistently increased earwig captures. The use of plastic bottles to contain the cardboard traps greatly reduced trap catch. Finally, we found evidence that traps left in the field for longer periods of time can increase earwig capture, possibly due to the accumulation of earwig aggregation pheromone. Overall, the standard unbaited corrugated cardboard trap was the most effective and practical earwig monitoring trap.

The braconid wasp Microplitis manilae (Hymenoptera: Braconidae) is a solitary, koinobiont endoparasitoid of young Spodoptera litura (Fabricius) larvae and one of its most crucial natural parasitic enemies.The establishment of a stable and sufficient population of M. manilae by rearing them in a laboratory is the cornerstone of field release management. However, when reared in a laboratory, M. manilae is affected by temperature. Here, we attempted to optimize the rearing temperature of M. manilae for parasitizing second-instar S. litura larvae by examining the effects of rearing at 5 temperatures: 16 °C, 20 °C, 24 °C, 28 °C, and 32 °C. Our results suggest that the development of the parasitoid progeny speeded up with shorter durations of the egg–larval, pupal, and preadult stages with the increase in temperature from 16°C to 32 °C.The parasitism rate and fecundity of M. manilae upon parasitizing second-instar S. litura larvae increased with rearing temperature from 16°C to 24 °C, with the peaks at 24 °C reaching 52.90% and 111.70 eggs/female, respectively, and then decreased at 28 °C to 32 °C. At 24 °C, the sex ratio (0.22) was the lowest, whereas the emergence rate (68.54%) did not differ significantly compared with those at other temperatures. Meanwhile, at 28 °C, the parasitism rate, fecundity, and emergence rate approached the levels at 24 °C, whereas the sex ratio was higher (0.29) than at 24 °C.These findings suggest 24 °C to 32 °C is the most appropriate temperature range for M. manilae mass rearing under laboratory conditions.

Aphids and numerous other phloem-feeding insects primarily rely on sucrose in the phloem to locate their feeding sites. However, it is still unclear whether this sweet perception process could serve as a target for aphid control. In this study, we investigated the impact of the sweet taste inhibitor sodium salt of 2-(4-methoxyphenoxy)-propionic acid (lactisole), a widely used food additive that binds to sugar receptors, on the feeding behavior and performance of aphids. Our findings indicate that both the green peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) and the English grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae) avoided settling on an artificial diet containing lactisole or on host plants treated with lactisole. In addition, these aphid species showed reduced weights when feeding on the artificial diet containing lactisole or on seedlings root drenched by lactisole. Furthermore, data from the electrical penetration graph revealed that S. avenae exhibited a greater number of phloem probes but significantly shorter mean and total phloem ingestion durations when feeding on wheat plants root-drenched by lactisole. It is worth noting, however, that root drenched by lactisole had a significant inhibitory effect on plant growth. These findings suggest that the sweet taste inhibitor lactisole may reduce aphid feeding preference and growth, offering a new avenue for aphid control strategies.

Species distribution modeling is extensively used for predicting potential distributions of invasive species. However, an ensemble modeling approach has been less frequently used particularly pest species. The bird cherry-oat aphid Rhopalosiphum padi L. is an important pest of wheat (Triticum aestivum L.) worldwide and causes 30% yield losses. Here, we developed a series of ensemble models with multiple variables to predict the habitat suitability of this pest at a global scale. The current suitable habitat for R. padi is mainly distributed in East Asia, South Asia, Europe, southern North America, southern South America, eastern Australia, and New Zealand. The highly suitable regions are primarily distributed in east of China, Japan, most of North America, southeastern South America, most of Europe, and southeastern edge of Australia. In future scenarios, the suitable habitats will undergo a significant contraction overall northward, and no moderately nor highly suitable habitats are predicted for this pest in other areas. Our findings indicate that a high risk of R. padi outbreaks currently exists for the highly suitable regions mentioned above, especially with wheat cultivation, but the capacity of R. padi to cause such outbreaks will weaken in the future. Climate-associated factors are significantly more important than land use, elevation and host-plant factors, and the BIO11 (mean temperature of the coldest quarter), in particular, predominated in shaping projections of R. padi's distribution. The predicted distribution pattern and key ecological factors affecting this pattern identified herein could provide important guidance for developing management policies targeting this economically important pest.

The Jack Beardsley mealybug, Pseudococcus jackbeardsleyi Gimpel & Miller (Hemiptera: Pseudococcidae), is a dangerous invasive pest that feeds on plants more than 115 genera from 54 families, and has spread over 59 countries or regions, often causing direct and indirect damage to host plants, and resulting in significant economic losses. In this study, we assessed the potential global distribution of P. jackbeardsleyi using a Maximum Entropy (MaxEnt) model under current and future climate scenarios. Here, we obtained prediction models with high credibility and accuracy, which showed that isothermality (Bio 3) and annual precipitation (Bio 12) were the environmental variables with the largest contribution on the potential distribution of this pest.The potential distribution areas predicted by this study were mainly located in South America, Central Africa, the southern regions of Asia and the eastern coast of Australia. Under future climate scenarios, the total geographical distribution of this pest will contract to varying degrees by the end of this century, but the highly suitable areas will increase. This study provides a reference for the development of control strategies, but also offers a scientific basis for the effective biological control of this pest.

Graphical Abstract

This study predicted the potential geographic distribution for the invasive scale Jack Beardsley mealybug under different climate scenarios with MaxEnt, and discussed preventive and control measures against this pest.

Climate change has a substantial impact on the quality and diversity of insect pests, which may have adverse ecological and economic effects. The family Chrysomelidae represents one of the most economically and ecologically important groups within Coleoptera, with species acting as agricultural pests and contributing substantially to biodiversity in arid regions. Based on bioclimatic, topographic, and vegetation data, the current and future distributions of 4 chrysomelids (Caryedon acaciae (Gyllenhal, 1833), Chaetocnema pulla Chapuis, 1879, Phyllotreta cheiranthi Weise, 1903, and Spermophagus sericeus (Geoffroy, 1785)) in Saudi Arabia were predicted using MaxEnt modeling for 2050 under 2 Shared Socioeconomic Pathways (SSPs), SSP126 (low emission) and SSP585 (high emission) scenarios. The leaf beetle models showed strong performance, with average area under the curve (AUC) values ranging from 0.86 to 0.96 and average TSS values ranging from 0.52 to 0.65. Five predictors were chosen for each species from 21 environmental variables. The results show that the key ecological factors that influence species distributions varied, with vegetation being the most influential. According to habitat suitability maps, in the future, such distribution will be severely altered, mostly by climate change. More precisely, C. acaciae will face minor range shifts, while C. pulla, P. cheiranthi, and S. sericeus will expand their ranges substantially, especially in the Eastern Province. Our results confirm the importance of implementing adaptive pest-management strategies to address the potential range expansions of various agricultural pests, which could intensify local ecological challenges and pose a heightened threat to agricultural systems.

The spotted lanternfly (Lycorma delicatula) and spongy moth (Lymantria dispar) are notorious invasive forest pests that are spread through human-mediated transport to invade new habitats. In this study, spotted lanternfly and spongy moth eggs were exposed to various temperature-exposure time (35 to 70 °C and 15 to 135 min) treatments in the laboratory. Spotted lanternfly egg masses were collected from various sites in 2022 and 2023, while the spongy moth egg masses were obtained from lab-reared colonies. Heat treatments were applied using an Isotemp microbiological incubator in the spring of 2023 and the spring and fall of 2024. No eggs of either species hatched when exposed to temperatures ≥ 60 °C for durations longer than 15 min. Spotted lanternfly egg hatch declined at temperatures ≥ 45 °C, while reduced hatch of spongy moth eggs was not observed until temperatures reached ≥ 50 °C.The season (spring or fall) in which the eggs were heat treated did not affect the hatch rate of spotted lanternfly eggs; however, spongy moth eggs were more vulnerable in the fall than in the spring.These findings suggest that heat treatment regimes that are already being used to kill insects in wood may effectively kill the eggs of both species on various substrates and that protocols for killing eggs at lower temperatures on more sensitive substrates may be possible by using longer-duration exposures.

The citrus pest Cacopsylla citrisuga (Yang & Li), a vector for Citrus Huanglongbing (HLB), exhibits distinct sensitivity to temperature variations. This study utilized an age-stage, 2-sex life table to evaluate the development and reproduction of C. citrisuga across 5 temperatures (17, 20, 25, 28, and 31 °C). The findings indicate that Cacopsylla citrisuga can complete its life cycle within the range of 17–28 °C, with optimal temperature at 20 °C, where the highest survival and fecundity rates in females were observed. An increase in temperature correlates with a decrease in developmental duration for all stages, with the shortest at 28 °C.The net reproductive rate (R₀) peaked at 20 °C, while the intrinsic rate of increase (r) and the finite rate of increase (λ) increased with the increase of temperature. Conversely, the average generation time (T) decreased with the increase of temperature, underscoring the pivotal role of temperature in population dynamics. The developmental threshold temperature and effective accumulated temperature were determined for each stage, furnishing crucial parameters for pest management strategies. This research highlights the importance of temperature in dictating the distribution and prevalence of C. citrisuga, offering valuable insights for the development of targeted control measures against this HLB vector.

Graphical Abstract

Forested wetlands support diverse biota and provide a wide range of ecosystem services. Archips goyerana Kruse (Lepidoptera:Tortricidae) is a native pest that defoliates baldcypress (Taxodium distichum var. distichum (L.) Rich.; Cupressaceae) and pondcypress (Taxodium distichum var. imbricarium (Nuttall); Croom), 2 keystone trees throughout forested wetlands of the southeastern United States. Outbreaks of the A. goyerana have been isolated to southeastern Louisiana, where they have caused reduced growth, crown dieback, and limited tree death. However, aerial detection surveys indicated that severe defoliation by A. goyerana has been affecting wetlands further east within the region. Given the possibility of expanding outbreaks, it is important to understand the timing of A. goyerana activity, duration of the flight period, and efficacy of different trap types to guide survey efforts. We deployed traps in a paired design, one bucket trap and one delta trap, each baited with synthetic A. goyerana sex pheromone at 30 sites throughout the range of baldcypress. Over 2 field seasons, we checked traps weekly and quantified the number of A. goyerana caught per trap type, ability of each trap type to detect a single moth (trap sensitivity), and growing degree days, using a base temperature of 5 °C accumulated at the onset, peak, and cessation of the flight period. We found that delta traps caught more moths but sensitivity of traps was equal between the 2 trap types. Analyses of phenology indicated that A. goyerana flight occurred between ∼1,000 and 1,600 growing degree days. Optimizing trapping practices for A. goyerana may improve detection of endemic populations and help identify areas potentially at risk of experiencing outbreaks.

Megalurothrips usitatus (Bagnall) (Thysanoptera:Thripidae), is an important pest in cowpea-growing areas of south China. To study control strategies, M. usitatus has been raised for multiple generations in the laboratory. Considering the impact of supplemental nutrients on colony fitness during laboratory rearing is crucial for achieving a significant population of uniformly developed individuals. Here, an age-stage, 2-sex life table for M. usitatus was developed to examine the impacts of F₀ M. usitatus adults fed on 3 different supplemental diets (20% sucrose solution, 20% pollen solution, and 20% honey solution) on the development, fecundity, and population growth of F₁ M. usitatus.The findings indicated that, compared to thrips fed on water, F₀ adult thrips provided with 3 supplementary diets exhibited a reduction in the developmental duration for each instar, an increase in fecundity, and an extension of the lifespan of F₁ M. usitatus, with honey yielding the best results. Similarly, the addition of supplemental nutrients resulted in a reduction in the mean generation time (T) and an enhancement of the net reproductive rate (R₀), intrinsic rate of increase (r), and finite rate of increase (λ) compared to the control group.The effects were highest for honey, followed by pollen, and then sucrose.This study provides favorable evidence concerning the direct impacts of parental nutrition supplementation on the fitness of offspring in insects, and provides information to aid indoor rearing of M. usitatus.

Effectively mass-rearing insects is critical for research, for environmentally friendly technologies like sterile insect technique, producing biological control agents, and enabling novel pest control methods such as those based on genetics or symbionts. While constant temperature conditions are typically used in mass-rearing, at what is considered an optimum value that produces the fittest insects, homeostatic conditions do not reflect the real world. We investigated the performance of mass-reared adult Ceratitis capitata Wiedemann (Diptera: Tephritidae) under constant (24 °C) and oscillating (mean 24 °C with 4 and 10 °C range) temperature regimes. Insect survivorship, flight ability, and female fecundity were assessed across the temperature regimes. Additionally, we compared adult C. capitata performance under environmental chamber and outdoor conditions to determine if temperature and humidity as simulated in the chambers resulted in similar performance outcomes for the insects as being outdoors. Male C. capitata under the 10 °C range treatment had higher survival probability at 55 d postemergence compared to the constant temperature regime, while females showed no significant differences in survivorship among temperature regimes. Flight ability and fecundity were not significantly affected by temperature regimes, though the 10 °C range group showed the highest fecundity. Comparisons between environmental chamber and outdoor conditions revealed minimal differences in performance metrics. Our findings suggest that the field performance of mass-reared male adult C. capitata can be improved by oscillating temperature regimes in mass-rearing facilities.

Mate-finding and host localization by nocturnal moths are predominantly mediated by olfactory signals and cues, respectively. Nevertheless, some nocturnal moth species rely on olfactory and visual cues to locate resources, such as flowers. Although traps are indispensable for the detection and monitoring of corn earworm moths, Helicoverpa zea (Boddie), a generalist and highly destructive crop pest, the role of visual cues in locating a pheromone source is poorly understood. Here, we investigated whether trap color influences the trap catch of the corn earworm. We showed that trap design affected male H. zea trap catch, with Hartstack-type traps being more effective than bucket traps, and more H. zea males were trapped in light-colored traps (white, yellow). However, under the dim ambient night conditions, when H. zea males fly, it is unlikely that they can discern trap colors. Instead, it is probable that H. zea males discriminate traps on the basis of their gray-scale reflectance, ranging from white to black. We found a positive correlation between trap captures and the relative luminance of dyed cheesecloth fabrics that we wrapped around Hartstack traps. Our findings suggest that at night, H. zea integrates the visual contrast between the trap and foliage background (ie apparency of the trap) in locating sex pheromone-baited traps.

Graphical Abstract

The efficacy of aerial application and chemigation of insecticides is not well explored for western bean cutworm, Striacosta albicosta (Smith), management in corn. In the short term, inadequate application of insecticides can lead to control failures when insect pests are not effectively targeted. In the longer term, exposure to sublethal insecticide concentrations can contribute to the evolution of insecticide resistance.The goal of this study was to compare aerial application and chemigation under simulated conditions to determine the most effective insecticide application method for managing S. albicosta.Three larval stages were exposed to the highest and lowest label rates of commercial formulations of bifenthrin (36.8 and 112.1 g a.i. ha^–1) and chlorantraniliprole (52.7 and 75.1 g a.i. ha^–1). Experiments were conducted in spray chambers, utilizing a carrier volume of 18.7 L ha^–1 for aerial application and 1.57 cm ha^–1 for chemigation. Mortality was recorded at 16, 24, and 41 h after infestation. The simulated aerial application was more effective than simulated chemigation in controlling S. albicosta, resulting in 100% mortality 24 h after infestation. Within the chemigation applications, chlorantraniliprole treatments were effective at both rates for all instars, while the high rate of bifenthrin exhibited greater efficacy than the lower rate. In conclusion, it was evidenced that the same insecticide active ingredients do not yield equivalent efficacy when applied via aerial application compared to chemigation.The present study highlights the importance of selecting appropriate insecticide application methods in controlling S. albicosta larvae.

Transgenic corn (Zea mays L.) expressing insecticidal toxins from Bacillus thuringiensis (Bt) helps to control or suppress injury from a range of target insect pests.This study summarizes the yield benefits of Bt corn from field trials in Georgia, North Carolina, and South Carolina evaluating Bt and non-Bt corn hybrids from 2009 to 2023. For Cry1A.105 + Cry2Ab2 and Cry1Ab + Cry1F Bt corn, the percentage increase in yield between Bt and non-Bt corn hybrids did not vary significantly among years or states. Across years, the percentage increase in yield for both Bt traits relative to non-Bt corn hybrids increased with planting date, indicating that the yield benefit of planting Bt corn was greater later in the growing season. On average, Bt hybrids in both families had a significantly higher yield compared to their non-Bt pairs, with yields declining in later planting dates. Yields declined with increasing kernel injury from Helicoverpa zea (Boddie) and leaf injury from Spodoptera frugiperda (J. E. Smith) in both Bt and non-Bt hybrids. While insect pressure increased in later planted corn trials, identifying causal relationships between increases in insect damage and associated yield losses in corn is challenging given the numerous factors that influence corn yield during the season. In addition to illustrating the highly variable yield benefits of planting Bt corn, our study suggests that yield increases in Bt corn may occur more frequently than previously documented in the southeastern United States.

Cotton seed bug, Oxycarenus hyalinipennis (Hemiptera: Oxycarenidae), was discovered in southern California in 2019. Surveys have found it within 160 km of cotton producing areas. While often only a minor pest in its native range, there are justified concerns that O. hyalinipennis could become a major pest of US-grown cotton. To proactively prepare for this possibility, 12 US-registered formulations and 1 experimental formulation were assessed in the laboratory for efficacy against O. hyalinipennis, using both contact and ingestion bioassays. Six formulations, consisting of acephate, dinotefuran, flupyradifurone, and imidacloprid with initial efficacy against O. hyalinipennis were used for subsequent dose-response bioassays. These compounds had LC₅₀ values well below maximum labeled rates, although LC_99.9 values often exceeded maximum label rates. Results indicate that if O. hyalinipennis infests cotton production regions, both selective and broad-spectrum options will be available for management.These findings establish a baseline for developing an integrated pest management program that can reduce potential damage from O. hyalinipennis, preserve natural enemies, and contribute to resistance management in cotton production areas.

In the southern United States, thrips are a significant early season pest of cotton. In the United States, in 2022, 98% of cotton acres were infested with thrips, and, of those acres, 45% were treated for thrips.Thrips injury resulted in over $113 million dollars in losses plus control costs to the cotton industry in the United States that year. A new Bacillus thuringiensis trait known asThryvOn has been commercialized to provide control against thrips.There is ongoing debate about the need for an insecticidal seed treatment to improve thrips control on ThryvOn varieties. Field studies were conducted to determine if the addition of an imidacloprid seed treatment improved efficacy against tobacco thrips and to determine if reduced rates of seed treatments (0, 25, 50, 75, and 100% of the labeled rate) provided benefits for thrips control inThryvOn cotton.To control for infestation pressure, a complementary greenhouse study was conducted using the same treatments under controlled conditions. Imidacloprid provided only a limited benefit for improved management onThryvOn cotton in the greenhouse study, but no benefit in the field study. Efforts in pest surveillance should be continued inThryvOn cotton to allow for foliar applications when warranted based on established thresholds. No conclusions can be drawn about the benefits of an imidacloprid seed treatment for resistance management inThryvOn cotton from this study, but these data suggest that any benefit would be minimal.

Industrial hemp, Cannabis sativa L., is an herbaceous annual plant that has recently re-entered crop production both in the field and in greenhouses within the United States. Like many agronomic crops, hemp production faces several insect pest challenges. Aphids pose a unique threat to hemp, being found in both indoor and outdoor production. Aphids affect hemp by reducing plant growth, bud production, concentrations of cannabinoids, and removing photosynthate. Additionally, aphids are vectors of plant viruses, and several species are known to transmit viruses to hemp. Limited research exists regarding the host suitability of hemp for common aphid pests in Louisiana. Thus, experiments were conducted to determine the life table statistics and feeding behaviors of Myzus persicae, Aphis gossypii, and Phorodon cannabis to determine the potential pest population dynamics of these pests on hemp. Hemp cv. Maverick was not a good host for either A. gossypii or M. persicae, resulting in negative intrinsic rates of increase and no sustained colonization. Although individuals of M. persicae and P. cannabis initiated probes at comparable rates, M. persicae probe durations were significantly shorter and probes were more frequent, indicating an absence of positive responses to probing hemp. A significant difference was observed in the percentage of individuals of A. gossypii initiating probes, and probe duration was significantly shorter than P. cannabis and significantly longer than M. persicae. Both A. gossypii and M. persicae spent significantly less time probing in phloem when compared with P. cannabis. These electrical penetration graph results indicate that A. gossypii and M. persicae do not find C. sativa cv. Maverick a suitable host; however, both species of aphids may still pose a threat to C. sativa production as virus vectors.

The black cutworm Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) can damage the cotton seedlings and induce destructive yield loss. Seed coating with systemic insecticides is a cost-effective alternative to control A. ipsilon during the early stage of cotton, but the control efficacy and exposure risk to honeybees remain unclear. This study evaluated the control effects of the anthranilic diamide insecticide chlorantraniliprole on A. ipsilon in cotton crops and the corresponding exposure risks to honeybees. Field studies revealed the control efficacy of chlorantraniliprole at 2 or 4 g/kg seed was greater than 75%, which was comparable to its spray control during the seedling development stage. A residual toxicity trial revealed that chlorantraniliprole treatment had a dose–response control effect on A. ipsilon during the 19 days after sowing. The residue levels of chlorantraniliprole in the stem bases and soil were found consistent with the residual toxicity against A. ipsilon. In the cotton flowering period, the highest detection frequency and residue of chlorantraniliprole were found in pollen from the plots treated with 4 g/kg seed. By using 2 independent risk assessment approaches, the exposure risk of chlorantraniliprole seed treatments were evaluated to be acceptable to honeybees. Overall, chlorantraniliprole coated with 2 g/kg seed was an effective alternative for controlling A. ipsilon at the cotton seedling stages.

Graphical Abstract

In 2019, the soybean gall midge (Resseliella maxima Gagné) was identified as a new pest and species in the US Midwest, causing injury to soybean (Glycine max (L.) Merr.). Infestation of R. maxima in soybean starts with females laying eggs in the fissures or cracks that develop at the base of soybean at the V2 growth stage. These fissures can be found on soybean from the soil surface to the cotyledonary node. After eggs hatch, larvae feed inside the stem, leading to wilting and death of the plants. In 2021, hilling was tested as a cultural tactic at the V2 stage, where soil was placed at the base of stems covering the fissures, resulting in a reduction in soybean gall midge infestation. To better understand this cultural control practice, hilling was performed at different timings at different vegetative (V2, V5) and reproductive (R2) soybean growth stages during the 2022 and 2023 growing seasons. We hypothesized that a greater abundance of larvae and increased plant injury would occur with later hilling applications. The results showed that soybean hilled at V2 and V5 stages had a lower infestation and higher yields compared to hilling later. The results of this study demonstrate that hilling during vegetative growth stages can reduce R. maxima infestation and prevent yield loss.

Plant-specific insect scouting and prediction are still challenging in most crop systems. In this article, a machine-learning algorithm is proposed to predict populations during whiteflies (Bemisia tabaci, Hemiptera; Gennadius Aleyrodidae) scouting and aid in determining the population distribution of adult whiteflies in cotton plant canopies. The study investigated the main location of adult whiteflies relative to plant nodes (stem points where leaves or branches emerge), population variation within and between canopies, whitefly density variability across fields, the impact of dense nodes on overall canopy populations, and the feasibility of using machine learning for prediction. Daily scouting was conducted on 64 non-pesticide cotton plants, focusing on all leaves of a node with the highest whitefly counts. A linear mixed-effect model assessed distribution over time, and machine-learning model selection identified a suitable forecasting model for the entire canopy whitefly population. Findings showed that the top 3 to 5 nodes are key habitats, with a single node potentially accounting for 44.4% of the full canopy whitefly population. The Bagging Ensemble Artificial Neural Network Regression model accurately predicted canopy populations (R² = 85.57), with consistency between actual and predicted counts (P-value > 0.05). Strategic sampling of the top nodes could estimate overall plant populations when taking a few samples or transects across a field. The suggested machine-learning model could be integrated into computing devices and automated sensors to predict real-time whitefly population density within the entire plant canopy during scouting operations.

The Anoplophora chinensis (Coleoptera: Cerambycidae) (Forster), a serious phytophagous pest threatening Castanea mollissima Blume and Castanea seguinii Dode, poses risks of ecological imbalance, significant economic loss, and increased management difficulties if not properly controlled. This study employs optimized MaxEnt models to analyze the potential distribution areas of A. chinensis and its host plants under current and future climate conditions, identifying their movement pathways and relative dynamics. Results indicate that all models achieved an average AUC value exceeding 0.86, demonstrating low complexity and high predictive accuracy. The key climatic variables influencing the geographic distribution of A. chinensis and its host plants include temperature and moisture-related bioclimatic variables such as mean diurnal range, minimum temp of coldest month, mean temp of wettest quarter, annual precipitation, precipitation of driest month, and precipitation seasonality. Under both current and future conditions, these 3 species are primarily distributed in the southwestern regions of China. Notably, the suitable growth area for all 3 species shows varying degrees of increase. Additionally, C. mollissima and C. seguinii exhibit a trend of eastward displacement in response to climate change. Overall, the findings provide significant practical value for the monitoring, early warning, and targeted control strategies for A. chinensis. Furthermore, these results offer a basis for timely conservation strategies to mitigate the potential impacts of climate change.

Balsam woolly adelgid, Adelges piceae (Ratz.) (BWA), invasive in North America, was first detected on subalpine fir [Abies lasiocarpa (Hook.) Nutt.] in several northern Utah counties in 2017. BWA phenology is known to vary by elevation and climate; a degree-day (DD) model focused on population expansion into the Intermountain West is needed. Bark samples were collected weekly from infested subalpine fir in early summer through late fall at 5 northern Utah sites from August 2020 to December 2022. At a single site, additional samples were collected biweekly to monthly during winter and spring.The presence of live individuals of all life stages in winter through early summer samples confirmed that life stages other than crawlers can successfully overwinter in northern Utah. Two generations were observed at all sites. Degree-day models were developed by fitting proportional adult counts and local air temperatures to Weibull distributions. Model fit was optimized with a 0 °C lower threshold, 30 °C upper threshold, and 1 Jan biofix. Completion of the first generation required 1,104 DD and 2 generations required 2,412 DD. Using the models and historical (1980 to 2020) temperatures, study sites were predicted to have thermal suitability for 2 generations at least 2 to 3 decades prior to detection in northern Utah, depending on site. Although upper estimates of future (2025 to 2099) predictions forecast a doubling of generations by 2060, knowledge of potential dormancies that may be disrupted in a changing climate is needed.The degree-day model will be a useful tool for predicting thermal suitability for future BWA expansion.

Graphical Abstract

Understanding the impact of the oak shothole leafminer Japanagromyza viridula (Coquillett) (Diptera: Agromyzidae) on oaks is important because oaks provide invaluable ecological services in forests and urban settings. In 2019 and 2020, shothole leafminers caused high levels of damage to oak trees in several states in the mid-Atlantic region.The objectives of this study were to compare oak shothole leafminer damage on the genus Quercus L. (Fagales: Fagaceae) including northern red oak (Quercus rubra L), chestnut oak (Q. montana Willd.), white oak (Q. alba L), scarlet oaks (Quercus coccinea Münchh.), and to fill critical knowledge gaps of oak shothole leafminer biology. Leaf area reduction, percent damaged leaves, foliage transparency, and crown dieback were calculated to compare damage experienced by the different oak species. Emergence and Malaise traps were used to assess adult population sizes. Chestnut oak was consistently the oak species with the least leaf area reduction and foliage transparency.The injuries on chestnut oak leaves were primarily small and uniform holes (“shotholes”) due to this leafminer. In contrast, northern red oak and scarlet oaks showed high susceptibility. Damaged leaves of these species frequently were deformed or incomplete, and the shotholes varied in size, resulting in greater leaf area reduction. Experiments showed that the conspicuous shothole damage caused by this leafminer is related to puncturing by the female flies into leaves of young buds. In conclusion, oak shothole leafminer is a native cryptic pest and outbreaks are visually apparent only when emergence coincides with oak bud and early leaf development.

Thrips parvispinus (Karny) (Thysanoptera: Thripidae), an invasive thrips species, poses a significant threat to global agriculture due to its polyphagous nature and rapid spread. Its recent arrival in the continental United States raises concerns about potential impacts on ornamental and vegetable crops. Dip treatments might serve as a phytosanitary practice for growers to start with plants free of visible pests. This study aimed to assess the efficacy of dip treatments using 4 biorational and microbial insecticides (mineral oil and Beauveria bassiana-based) in controlling T. parvispinus on bean seedlings. Following gentle agitation of cuttings, artificially infested with 10 second-instar (L2) larvae, for 15 s in each solution, thrips infestation was evaluated at 1, and 24 h postdipping, scoring the numbers of dislodged and dead larvae. Additionally, we tested whether dipping could cause phytotoxicity on bean (Phaseolus vulgaris L.), gardenia (Gardenia jasminoides Ellis), and mandevilla (Mandevilla splendens (Hook.f.) Woodson) cuttings during a 7-day period. Our results demonstrated that dip treatments effectively dislodged and killed T. parvispinus L2 larvae from infested cuttings, with BotaniGard-ES and Suffoil-X exhibiting the highest efficacy and a dislodgment rate of 80%–100%. BotaniGard-ES was the only product causing phytotoxicity on bean seedlings, but not on mandevilla and gardenia. Overall, we demonstrated that dip treatment using biorational insecticides is an additional tool that can be incorporated in the integrated pest management of T. parvispinus. These results hold implications for the broader application in the management of thrips across various plants propagated from cuttings.

The swede midge, Contarinia nasturtii Kieffer (Diptera:Cecidomyiidae), is a gall-forming insect pest that targets cruciferous plants. Since its introduction to North America in the early 2000s, the midge has expanded its range to include farming regions in Quebec and the Northeastern USA. In this study, we evaluated the susceptibility of 4 popular kale varieties—Green Curly—(Vates), Red Russian, Red Curly (RedBor), and Lacinato/Tuscan—to swede midge infestation in on-farm trials conducted over consecutive years. Our results indicate substantial variability in susceptibility among varieties, with Red Russian kale consistently exhibiting the highest damage incidence across both years. These findings provide valuable insights for developing effective integrated pest management (IPM) strategies tailored to organic and small-scale vegetable farming contexts, emphasizing the role of crop genetic resources in pest mitigation and sustainable agriculture. In addition, this study highlights the potential of non-chemical approaches for managing swede midge, leading to a more diverse and adaptable IPM toolbox for growers.

The European earwig F. auricularia L. is an omnivore that has only recently been identified as a direct, fruit-feeding pest of citrus. Here, we start to build the basic tools needed for integrated pest management for this species. We introduce a time-efficient sampling method based on small wooden boards placed on the ground, and we use them in a 2-yr survey of 93 commercial citrus blocks in California's San Joaquin Valley. Insecticides were not applied targeting F. auricularia in any of these citrus blocks. We find that F. auricularia populations are very low or undetectable in most blocks, with higher densities occurring only sporadically. To know when control measures should be implemented, we used video-monitoring of citrus tree trunks to characterize the timing of F. auricularia movement from their soil nests into the tree canopy. Movement of earwigs along the tree trunks was observed throughout our sampling period (22 March to 18 June), suggesting that control measures (sticky bands placed on trunks, or insecticides applied to trunks and surrounding soil surface) should be applied early, well before petal fall when fruit are susceptible to F. auricularia herbivory. Sticky barriers effectively reduced the vertical movement of 2 crawling arthropods, F. auricularia and the Fuller rose beetle Napactus godmanni, along citrus trunks. We failed to find any relationship between estimated F. auricularia densities and damage to maturing or harvested fruit. This highlights a set of important and still unresolved questions about the biology of this species, underscoring the need for additional research.

Increasing plant diversity in agroecosystems is often proposed as a way to reduce arthropod pest pressure and support natural enemy populations to reduce reliance on traditional chemical controls. Over 2 field seasons, we examined the effects of interplanting cantaloupe (Cucumis melo L. var. cantalupensis) with alsike clover (Trifolium hybridum L.) and Virginia wildrye (Elymus virginicus L.) on arthropod populations, cantaloupe yield, and fruit quality. Arthropod sampling through visual counts, sticky cards, and pitfall traps focused on herbivores and natural enemies across feeding guilds, with more specialized pests in the cucurbit system being identified to lower taxonomic levels. Living mulches might have delayed initial crop colonization by striped cucumber beetles (Acalymma vittatum F.) but had limited impact on beetle counts, which remained similarly low throughout the study across treatments. Aphid populations were lowest in wildrye interplanted plots, suggesting species-specific impacts on pest suppression. Beneficial arthropods, such as spiders, piercing predators, and parasitoids, were often more abundant in clover than in wildrye or monoculture plots, especially early in the season. However, cantaloupe yield was highest in monoculture plots, where fruit showed increased weight, size, and favorable color metrics compared to those from living mulch plots. These results indicate that while living mulches can support beneficial arthropods and possibly reduce early pest pressure, they may also introduce trade-offs in yield and quality. Future studies should explore adjustments to living mulch management in cantaloupe, such as reduced density or narrower planting strips, to optimize pest suppression benefits while limiting competition with the cash crop.

Strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae), is an important specialty crop in Florida, generating about $500 million in annual revenue. An invasive insect, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has emerged as a major strawberry pest, causing considerable yield and revenue loss in recent years. Pesticide application is the leading control option but is not always recommended due to resistance development. Host plant resistance (HPR) can be a novel option to manage S. dorsalis sustainably. Four commercial cultivars, ‘Florida Brilliance', ‘Florida Medallion FL16.30-128', ‘Sweet Sensation ‘Florida127', and ‘Florida Pearl FL16.78-109’, were evaluated for their performance in the 2021–2022 field season under the natural population of S. dorsalis. In 2022–2023 and 2023–2024, 3 more cultivars, ‘Strawberry Festival', ‘Florida Radiance’, and ‘Florida Beauty’, were added to this list. Twenty bare-root strawberry transplants were planted in each field plot, and each cultivar was replicated 8 times in a randomized complete block design. Damage on trifoliate, number of adults and larval S. dorsalis on trifoliate, number of flowers, and marketable fruit yield were assessed for each cultivar. Results revealed that ‘Florida Pearl 109’ had the highest insect count and damage index of all 3 year. ‘Strawberry Festival’ also showed the same trend after its introduction in the second year. ‘Florida Brilliance’ and ‘Sweet Sensation’ had the lowest damage index, lowest adult insect count, and higher marketable yield compared to ‘Florida Pearl 109’ and ‘Strawberry Festival’. Therefore, utilizing resistant cultivars can be an effective tool for managing S. dorsalis in the field.

German cockroaches (Blattella germanica (L.)) are a persistent pest in affordable housing and studies indicate that residents implement control on their own to deal with cockroaches within their homes. While many do-it-yourself (DIY) control options have proven ineffective, baits are widely considered to be a viable DIY solution for residents who do not have access to professional pest control services.To evaluate their efficacy, we tested consumer-use baits (Combat gel bait, Combat bait stations, and Hot Shot liquid bait stations) in both laboratory two-choice assays and in-home assays, comparing them with professional gel baits (Vendetta Nitro, Advion Evolution, and Maxforce FC Magnum). All baits (consumer- and professional-grade) caused > 80% mortality within 14 d in laboratory assays, including against home-collected German cockroach populations. However, the in-home efficacy of consumer-grade baits in comparison to their performance in laboratory assays was inconsistent, with some baits resulting in significant declines in trap catch in 1 month (Hot Shot liquid bait stations), some taking longer (Combat gel bait), and some never showing a decline (Combat bait stations). Discrepancies between product performance in laboratory and in-home studies are concerning and suggest that laboratory assays alone might not be indicative of the potential for control, especially in the context of the more complex home environment. Failures of consumer-grade baits may require re-evaluation of current recommendations for the use of consumer-grade cockroach baits as a viable control option for residents struggling with cockroach infestations without access to professional pest management.

The longlegged ant, Anoplolepis gracilipes, is a globally destructive invasive species owning to its devastating impacts on biodiversity and ecosystem functions in the regions where it has been introduced. InTaiwan, invasion of A. gracilipes has been associated with the declining of land crab populations in several hotspots. While liquid baiting program has been implemented in those areas, the operation is costly and labor-intensive since it typically requires the use and maintenance of bait stations.The goal of the current study was to evaluate the potential and effectiveness of hydrogel baits laced with borax as an alternative tool to control A. gracilipes. Laboratory studies demonstrated that hydrogel baits containing 3% borax achieved higher A. gracilipes mortality than those containing 2% and 1% borax. Specifically, hydrogel baits containing 3% borax resulted in >90% worker mortality within 21 d post-treatment (LT₅₀ = 5.1 d), along with significant reduction in brood weight (>90%) and substantial queen death (>80% of colony fragments). Furthermore, field experiment indicated that A. gracilipes workers preferentially retrieved small-size hydrogel beads (3.1 mm OD; proportion removed = 1.00 ± 0.00) compared to the larger ones (6.2 mm OD; proportion removed = 0.03 ± 0.03), which will facilitate efficient transfer of toxicant within the colony and may minimize nontarget impact. In conclusion, alginate hydrogel baits with 3% borax appear to be a promising tool against A. gracilipes, although their field efficacy against large supercolonial populations remains to be investigated.

Methoxyfenozide is an insecticide with a unique mode of action on the insect ecdysone receptor and has been registered for the control of insect pests all over the world. In the present work, Spodoptera frugiperda was exposed to sublethal and lethal concentrations of methoxyfenozide to determine its impact on specific biological traits, metabolic enzyme activity, and the expression of detoxification enzymes. The result showed that 72-h posttreatment with LC₅₀ and LC₇₀ of methoxyfenozide significantly reduced the fecundity (eggs/female) of the F₀ generation compared to those of the control group. However, the duration of the prepupal period was significantly increased. The exposure to LC₁₀, LC₃₀, LC₅₀, and LC₇₀ concentrations of methoxyfenozide significantly extended the developmental duration of larvae in F₁ individuals. The fecundity of the F₁ generation was significantly decreased, and the population life table parameters of F₁ were also significantly affected. The activity of carboxylesterases showed little significant change, whereas the activity of glutathione S-transferases (GSTs) and cytochrome P450 monooxygenases (P450s) was significantly altered after exposure to LC₁₀, LC₃₀, LC₅₀, and LC₇₀ of methoxyfenozide. In total, 24-, 48-, and 96-h posttreatment with LC₁₀, LC₃₀, LC₅₀, and LC₇₀ of methoxyfenozide could cause upregulation of P450 genes such as CYP6AE44, CYP6B39, CYP9A26, CYP9A58, CYP9A59, and CYP9A60, as well as GST genes including GSTe3, GSTe9, GSTe10, GSTe15, GSTo2, GSTs1, GSTs5, GSTm2, and GSTm3. These findings could be instrumental in elucidating the molecular mechanisms underlying the sublethal and lethal effects of methoxyfenozide to S. frugiperda.

Bombyx mori (L.) (Lepidoptera: Bombycidae) is an important economic insect, and Exorista sorbillans (W.) (Diptera: Tachinidae) is an endoparasitic pest of larval B. mori. Dimethoate is less toxic to B. mori than E. sorbillans and is used in sericulture to controlling E. sorbillans. To investigate the effects of dimethoate treatment on the gut microorganisms and physiological functions of B. mori, 16S rRNA sequencing was used to analyzed the composition and structure of the gut microbiota. This study investigated their role in enhancing silkworm resistance by screening dominant populations after dimethoate treatment. The results indicated that dimethoate did not alter the composition of the dominant gut bacterial groups in silkworm; however, it significantly increased the abundance of the gut bacteria Methylobacterium and Aureimonas, and decreased the abundance of Enterobacterales, Bifidobacterium, Blautia, Collinsella, Faecalibacterium, and Prevotella. Eleven strains of dimethoate-resistant bacteria were selected through in vitro culture, all of which were unable to grow when dimethoate was used as a carbon source. Additionally, a germ-free silkworm model was established to assess detoxifying enzyme activity in the midgut. The results revealed that the gut symbiotic microbiota can enhance dimethoate resistance by increasing detoxification enzyme activity. This study identifies a novel pathway for silkworm resistance to dimethoate based on gut microbiota, providing new insights into the role of symbiotic gut bacteria in insecticide metabolism.

Graphical Abstract

The fall armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), a notorious invasive pest, has been widely monitored for insecticide resistance. Since its invasion of China in late 2018, early to mid-stage monitoring of resistance is particularly crucial to inform effective control strategies. Resistance ratios (RRs) derived from bioassays offer valuable insights into the overall resistance levels of field populations, while the detection of resistance allele frequencies helps uncover the potential causes of resistance variation. In this study, we established a baseline of susceptibility in third-instar larvae to 7 insecticides using a laboratory strain Xinzheng2019 and assessed the resistance levels of 9 populations collected from central and southern China between 2022 and 2023. Compared to the susceptible Xinzheng2019 strain, 2 field populations showed low-level resistance (RR = 5-10) to indoxacarb, and one exhibited low-level resistance to chlorantraniliprole. Minor resistance (RR = 3-5) was observed in 2 populations to lambda-cyhalothrin, 5 to indoxacarb, and 5 to chlorantraniliprole. All populations remained susceptible (RR < 3) to spinetoram, emamectin benzoate, chlorfenapyr, and lufenuron. Molecular analysis of 11 mutation sites across 3 key resistance-related genes (Ace-1, GluCl, and voltage-gated sodium channel [VGSC]) revealed that 52.1% of all tested samples carried either homozygous or heterozygous resistance alleles at the F290V locus of the Ace-1 gene, while no resistance mutations were detected at other sites. Our findings offer valuable insights into the insecticide resistance status of S. frugiperda field populations in China and provide guidance for effective chemical insecticide use.

Onion maggot, Delia antiqua (Meigen), is a significant constraint on onion production across the temperate regions of North America. Early season infestations can reduce plant stands up to 75% if untreated. Effective management of D. antiqua has historically relied on insecticide seed treatments, with spinosad being among the most commonly used options. However, declining control efficacy observed on a NewYork onion farm over several years raised concerns about the potential development of insecticide resistance. The purpose of this research was to (i) evaluate the efficacy of spinosad seed treatment in managing D. antiqua in the affected field from 2021 to 2024 and (ii) to assess the population's susceptibility to spinosad using a laboratory bioassay. Results from field trials revealed that the percentage of control of D. antiqua using spinosad seed treatment relative to a noninsecticide treatment declined from 51% in 2021 to –83% in 2024. Laboratory bioassay results showed an increase in LC₅₀ values from insects collected from nontreated and spinosad-treated plants in 2023. These results document the first case of reduction in spinosad seed treatment efficacy in D. antiqua that has practical consequences for pest control (practical resistance). Given the critical role of spinosad seed treatment in onion maggot management, these results underscore the need for evaluating resistance prevalence in other populations across North America.

Pseudacysta perseae (Heidemann 1908) (Hemiptera: Tingidae), a foliar pest of avocados, was first discovered in urban San Diego County, California U.S. in 2004. In 2017, damaging populations of P. perseae were discovered in commercial Hass avocado groves in San Diego and Riverside Counties. The unexpected and rapid spread of P. perseae raised the question of whether this range expansion was an extension of the original incursion or the result of a second invasion event. Using sequences of the mitochondrial COI gene, we found strong evidence that P. perseae populations in southern San Diego County are comprised almost entirely of the single haplotype (A) that was detected in 2004. In contrast, newly established (2017 onwards) populations of P. perseae infesting commercial orchards consisted exclusively of a second mitochondrial haplotype (G). This haplotype is found in Florida and the Caribbean and is conclusive evidence that California has been invaded a second time. Molecular analyses also confirmed that invasive P. perseae populations in Hawai‘i are haplotype G, indicating that California and Hawai‘i populations may have originated from the same source area (possibly Florida), or that California may have acted as an invasion bridgehead for the invasion of Hawai‘i. Reproductive compatibility of the primary (haplotype A) and secondary (haplotype G) invasive populations in California was confirmed via a series of reciprocal laboratory crosses and results suggest that fertility of hybrid eggs is increased. The potential consequences of this second invasion into California by P. perseae are discussed.

Graphical Abstract

Wolbachia are bacterial endosymbionts found widely in arthropods and filarial nematodes. Infecting about half of all arthropod species, Wolbachia manipulate their hosts in various ways, including cytoplasmic incompatibility. Here, we investigated Wolbachia diversity in Bactrocera and Zeugodacus, two prevalent tephritid fruit fly genera, using molecular methods. Wolbachia was only detected in Zeugodacus apicalis (de Meijere) (Diptera: Tephritidae) and not in the other 7 studied species. This newly discovered strain, named wZap, belongs to supergroup B with a 1.3 Mb genome containing 1,248 genes. Phylogenetic analysis of its cytoplasmic incompatibility factor genes cifA and cifB revealed their placement within theType I clade. Given the presence of cif genes in the wZap genome, further research into their roles in fruit flies could be crucial for developing pest control strategies that exploit CI mechanisms.

Graphical Abstract

The invasive emerald ash borer (Agrilus planipennis Fairmaire) (EAB) has been devastating North American ash (Fraxinus spp.) resources for over 2 decades. In its native range, EAB attacks and kills primarily stressed ash trees. In North America, however, EAB also attacks healthy trees of every Fraxinus species encountered, most recently Oregon ash (Fraxinus latifolia Benth.). Successful EAB development has also been reported in European olive (Olea europaea L.).The recent detection of EAB in Oregon puts the future of these 2 hosts into question, as little is known about EAB's development in these species or how introduced biocontrol agents will respond. We conducted laboratory and field infestations of olive and ash in Delaware and Oregon to assess EAB development and associated parasitoid responses. We found no difference in the net population growth rate of EAB developing in Oregon ash versus green ash. However, these species supported significantly more population growth than olive, in which EAB net population growth rate was zero, with most larvae dying prematurely. Artificially infested olives were small, which may have negatively impacted phloem availability and larval survival. Future studies should be conducted investigating EAB development on larger olive material. Although no parasitism was observed in infested olive, as EAB larvae seldom reached life stages (third or fourth instars) susceptible to larval parasitism, late-instar larvae developing in Oregon ash were attacked by both Tetrastichus planipennisi Yang and Spathius galinae Belokobylskij and Strazanac, suggesting that biocontrol is a suitable option for this newly invaded region.

The tea aphid Toxoptera aurantii Boyer (Hemiptera: Aphididae) is a destructive pest that infests tea plants. The resistance mechanisms of the tea plant against T. aurantii infestation are largely unexplored. This study investigates the defensive response of tea plants to T. aurantii feeding using an aphid-resistant Camellia sinensis cultivar ‘Qiancha1’ (QC1) and an aphid-susceptible C. sinensis cultivar ‘Huangjinya’ (HJY). Transcriptomics and metabolomics analyses were conducted on 4 samples: QCCK (T. aurantii non-infested QC1), HJYCK (T. aurantii non-infested HJY), QC24 (T. aurantii-infested QC1 for 24 h), and HJY24 (T. aurantii-infested HJY for 24 h). The results showed that the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) in the 2 comparison groups (QCCK vs. QC24 and HJYCK vs. HJY24) were primarily enriched in metabolic pathways, including hormone signal transduction, phenylpropanoid biosynthesis and flavonoid biosynthesis. Following aphid infestation, the resistant cultivar QC1 exhibited more DEGs and DAMs than the susceptible cultivar HJY, indicating a stronger response to T. aurantii feeding stress. Additionally, the expression of phenylpropanoid- and flavonoid-related genes (CYP, 4CL, FLS, F3H, and LAR) was significantly upregulated in the resistant cultivar QC1 compared with that in the susceptible cultivar HJY. Metabolites involved in phenylpropanoid/flavonoid pathways, such as p-coumaroyl-CoA, caffeoylquinic acid, and feruloylCoA, were exclusively induced in QC1. These findings suggest that phenylpropanoid/flavonoid pathways play pivotal roles in tea plant resistance to T. aurantii infestation, providing valuable insights for the breeding and utilization of resistant germplasms.

Wheat is prone to insect infestations during harvesting, transportation, and storage, leading to heat, mold, and deterioration. Timely pest detection is vital for effective prevention and improved storage quality. Traditional methods, such as manual identification and biological information detection, have limitations, including low efficiency, grain damage, and difficulty in identifying pest larvae. This study proposed a method for detecting Sitophilus zeamais (S. zeamais) in the interior of wheat based on computed tomography technology and the Multi-feature and Vision Transformer U-Net model. The U-Net was enhanced with the Multi-Feature Extraction block and the Residual Vision Transformer block. After 200 training iterations, the model achieved a mean Intersection over Union of 94.4%. To use image processing technology to segment S. zeamais, create 3D models, and extract features such as volume, surface area, and length. S. zeamais develops through stages: egg, early larva, late larva, pupal, and adult. From epidermal erosion into the endosperm, it transitions from a round egg stage to a columnar shape and then develops various organs. The volume of the S. zeamais increases from 0.008 to 0.018 mm³ during the egg stage to 0.89 to 1.16 mm³ in the adult stage, and its length grows from 0.176 to 0.284 mm during the egg stage to 2.416 to 2.865 mm in the adult stage.This method offers accurate, rapid extraction and visualization of S. zeamais developmental information, supporting early-stage variation analysis and enhancing wheat quality and pest control.

Long-lasting insecticide-incorporated netting (LLIN) has been used to deliver pyrethroids for management of stored product insect pests in food facilities. However, the development of resistance to pyrethroids in stored product pests is a widespread and urgent problem, which threatens the efficacy of commercially available LLINs. A potential approach for enhancing LLIN efficacy is the use of insecticide synergists to inhibit detoxification enzymes and exacerbate the effects of pyrethroids. Here, we evaluated the synergistic properties of 3 detoxification enzyme inhibitors—piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP)—with LLIN against the red flour beetle Tribolium castaneum (Herbst), and the lesser grain borer Rhyzopertha dominica (Fabricius). Pre-exposure to PBO resulted in higher mortality after exposure to LLIN for T. castaneum and R. dominica. With pre-exposure to PBO followed by LLIN exposure, there was a trend for lower LT₅₀ values for both species, while the extent of synergistic effects was greater on R. dominica than T. castaneum. In contrast, with pre-exposure to DEM andTPP followed by LLIN exposure, there were no significant reductions in LT₅₀ values for both species. In addition, the presence of food had a significant effect on the recovery and delayed mortality in T. castaneum and R. dominica, reducing the efficacy of synergist and LLIN in combined exposures.This study provides baseline data towards improving the efficacy of LLIN against stored product pests.

Graphical Abstract

A sticky trap is a simple, low-cost method for the field estimation of insect population density. The present study was investigated the attraction of Stomoxys calcitrans using 5 different colors of sticky trap (blue, gray, transparent, white, and yellow). Throughout the sampling period, the sticky traps collected 1,559 S. calcitrans adults, of which 560 (36%) were females and 999 (64%) were males. The mean numbers of S. calcitrans on the 3 dairy cattle farms sampled differed significantly among the different trap colors, with both sexes being preferentially attracted to white or blue sticky traps. However, the white sticky traps were more effective at trapping S. calcitrans than the yellow and transparent sticky traps. Thus, a white-colored fly trap design was recommended for monitoring purposes.

Tropilaelaps mercedesae (Delfinado and Baker) is an emerging parasitic mite that can severely impact the Western honey bee (Apis mellifera L.). While T. mercedesae has been reported to be expanding its geographical range, the routes of inter-colony dispersal between A. mellifera colonies are still largely unknown. In this study, we used funnel traps to collect foraging honey bees exiting their colonies before performing an alcohol wash to collect any phoretic T. mercedesae mites. We found T. mercedesae on exiting adult honey bees; however, they were only detected when a colony had an elevated T. mercedesae brood infestation. We show that T. mercedesae can exit colonies through phoresy on adult A. mellifera which demonstrates the potential of these mites to be spread through the natural movement of A. mellifera honey bees among colonies.

Tricolus simplicisWood 1974 (Coleoptera: Curculionidae: Scolytinae) is reported to bore and reproduce on the branches of Robusta coffee (Coffea canephora) in Chiapas, Mexico.This is the first report of T. simplicis associated with Robusta coffee worldwide.The risk this insect poses for coffee production is discussed.

Se informa que Tricolus simplicis Wood 1974 (Coleoptera: Curculionidae: Scolytinae) perfora y se reproduce en las ramas del café robusta (Coffea canephora) en Chiapas, México. Este es el primer reporte de T. simplicis asociado con el café robusta a nivel mundial. Se discute el riesgo que este insecto representa para la producción de café.