Journal of Economic Entomology

Background: Resistance to protoporphyrinogen oxidase (PPO) inhibiting herbicides is mainly driven by diverse target-site mutations, reducing the effectiveness of this site of action in row crop systems. Fendioxypyracil is a newly developed PPO inhibitor with high intrinsic grass and broadleaf activity, but its performance against resistant populations and target-site enzyme variants remains insufficiently characterized. Results: Enzyme assays using PPO2 from Amaranthus palmeri and Setaria viridis demonstrated that fendioxypyracil maintained low IC50 values across a broad range of resistance associated mutations, including dG210 deletion and G210, R128, and G399 substitutions, whereas oxadiazon, tiafenacil, and saflufenacil showed substantial loss of potency. Greenhouse dose response experiments confirmed strong fendioxypyracil efficacy, with susceptible and G399A populations controlled at <3 g ai/ha, while dG210 and R128G populations showed only moderate shifts in sensitivity but remained effectively controlled at the recommended rate. Transgenic Arabidopsis thaliana expressing resistant PPX2 alleles exhibited faster and more severe injury with fendioxypyracil compared to saflufenacil. Field trials conducted in a PPO resistant Amaranthus palmeri population demonstrated that fendioxypyracil provided consistent weed control and density reduction, matching the performance of trifludimoxazin and saflufenacil while exceeding that of fomesafen. Conclusion: Fendioxypyracil provides robust and broad-spectrum activity against PPO resistant Amaranthus populations and target mutant enzymes, maintaining efficacy across diverse mutation backgrounds. These results demonstrate its potential as an effective tool for managing PPO inhibitor resistance and sustaining weed control in row-crop production systems.

Nutrition plays a fundamental role in insect physiology, yet whether growth, immunity and stress responses share a common nutritional optimum remains poorly understood. Using the Geometric Framework for Nutrition, we investigated how dietary protein and carbohydrate balance regulate multiple physiological functions in the specialist herbivore Plutella xylostella. Growth was jointly determined by protein and carbohydrate intake, with maximal biomass accumulation constrained primarily by protein availability. Immune traits showed distinct nutritional optima: total hemocyte counts and phenoloxidase activity were maximised at intermediate protein-carbohydrate (P:C) ratios, whereas survival following Bacillus thuringiensis challenge depended predominantly on protein intake. Antioxidant and detoxification responses likewise varied non-linearly across the nutrient landscape, with individual enzyme systems each exhibiting distinct nutrient-dependent optima. Importantly, no single macronutrient balance simultaneously maximised growth, immune performance and oxidative homeostasis, demonstrating that these functions have divergent nutritional requirements. Together, these findings show that macronutrient balance generates competing physiological demands, offering an integrated view of nutrient-dependent regulation of growth, immunity and stress physiology in a specialist herbivore.

To implement adequate nutritional landscapes to bumble bees and inform conservation efforts, we need a better understanding of how different pollen sources impact bumble reproductive performances and phenology. We assessed the impact of multiple native pollen on bees reproductive success by feeding 40 wild-caught Bombus impatiens and B. griseocollis queens with either commercially wildflower pollen mix commonly used to breed Bombus queens (control group) or 75% red maple pollen (Acer rubrum) and 25% pollen mix (RM group). In a second experiment, we monitored the reproductive success of 45 microcolonies of workers, harvested from B. impatiens colonies. Microcolonies were fed either: 1) pollen mix (N=15), 2) pollen mix and hawthorn (Crataegus canadensis, N=15), or 3) pollen mix and sumac (Rhus typhina, N=15). In experiment 1, RM significantly increased reproductive outputs for both species. RM-fed founding queens were twice more likely to produce workers, and produced them significantly earlier, though total number of workers did not vary between groups. However, RM-fed founding queens produced significantly more brood cells, males and gynes than control colonies, and produced them significantly earlier. In experiment 2, we found an interaction between initial colony diet and current microcolony diet. Overall, workers harvested from RM-fed colonies produced significantly more brood cells and males than workers harvested from control colonies. However, when fed hawthorn pollen during experiment 2, workers from control colonies performed as well as workers from RM-fed colonies. This suggests carry-over effects from early pollen sources provided to colonies on workers, which may be circumstantially offset by pollen sources with specific nutrient profile. Using detailed nutritional information of each pollen (including data on 32 nutrients), we provide nutritional requirements of pollen to support bumble bee reproduction, especially regarding vitamin B3 and vitamin C contents. This study will help inform land managers and captive breeding programs on the ideal pollen sources for bumble bees to ensure reproductively successful colonies.

The expansion of global trade has increased the risk of unintentional introductions of woodboring insects outside their native ranges, which can cause considerable ecological and economic damage. Monitoring efforts for native and non-native species of woodborers rely heavily on semiochemical-baited traps. With the goal of improving detection efforts of longhorned beetles (Coleoptera: Cerambycidae) and their associates, we conducted field bioassays in loblolly pine dominated and bottomland hardwood forest ecosystems, which are representative of subtropical Louisiana. We tested the impact of attractant composition, trap design, and the application of a friction reducing compound on the capture of longhorned beetles. We compared the Synergy Multi-Trap System with and without Fluon, and the Synergy Funnel Trap II with Fluon, baited with multicomponent cerambycid lures and ethanol or ethanol alone. In total, we collected 5,303 beetles comprising 44 species. Traps baited with cerambycid lures and ethanol captured ~11X more individuals than the traps baited with ethanol. We identified novel attractants for 6 species of longhorned beetles. When Fluon was applied, both the Synergy Multi-Trap System and Funnel Trap II were equally effective at capturing cerambycids. Application of Fluon significantly increased the trap capture of the Synergy Multi-Trap System by ~4X compared to the same trap type without Fluon. Our results contribute to our understanding of the factors influencing trap captures and the chemical ecology of woodboring insects thereby helping the development of early detection and rapid response monitoring programs in subtropical regions of the United States and elsewhere.

Stink bugs (Hemiptera Pentatomidae) are major agricultural pests worldwide, including both native and invasive species. In France, for instance, Halyomorpha halys has rapidly expanded its range, affecting key crops such as hazelnuts, apples, and vegetables. Meanwhile, several native, polyphagous species - Nezara viridula, Palomena prasina and, to a lesser extent, Graphosoma italicum - are re-emerging and impacting diverse crops because of changes in agricultural practices and climatic conditions. Egg parasitoids represent promising biological control agents for these pests, be it through conservation, augmentation or introduction biological control. However, their actual potential is not precisely documented due to a lack of ambitious surveys and possible taxonomic issues. This study aims to address this gap by compiling results obtained from various of egg parasitism surveys of Pentatomidae in France and implementing a large-scale DNA Barcoding approach (2000 individuals) for the emerged parasitoids. Our results indicate a high diversity of egg parasitoids, and detected some taxonomic issues and molecular inconsistencies that warrant further study. Among the three families of egg parasitoids recovered (Encyrtidae, Eupelmide, and Scelionidae), Scelionidae was the most abundant and diverse with nine species of Trissolcus (including the two adventive species, Tr. japonicus and Tr. mitsukurii) and four Telenomus species (including two unidentified to species). Scelionidae dominated the parasitoid assemblages associated with most of the Pentatomidae host species, except for H. halys for which the eupelmid Anastatus bifasciatus was the most common species.

The generalist Helicoverpa armigera and the specialist Helicoverpa assulta are closely related noctuid pests and are among the few insect herbivores capable of feeding on and damaging hot pepper fruits, which contain the defensive compound capsaicin. Cytochrome P450 monooxygenases (P450s) contribute to the metabolism of plant defensive compounds and can facilitate insect adaptation to chemically defended host plants. Here, we identified CYP6AN1 in H. assulta (HassCYP6AN1) and comparatively characterized the CYP6AN1 orthologs from H. armigera (HarmCYP6AN1) and H. assulta. RACE identified one full-length HarmCYP6AN1 transcript and three full-length HassCYP6AN1 transcript isoforms. The HassCYP6AN1 isoforms contained distinct 5' UTRs generated by alternative transcription initiation and splicing but shared an identical coding sequence. Sequence comparisons and phylogenetic analysis supported their assignment as orthologs. Constitutive CYP6AN1 expression was higher in the H. assulta midgut, whereas dietary capsaicin significantly induced CYP6AN1 expression in the H. armigera midgut. Recombinant CYP6AN1 proteins were co-expressed with NADPH-cytochrome P450 reductase in Escherichia coli, and their substrate-metabolizing activities were evaluated using HPLC-based depletion assays. Both orthologs metabolized capsaicin, but HarmCYP6AN1 exhibited an approximately 2.3-fold higher depletion activity than HassCYP6AN1 under the conditions tested. HarmCYP6AN1 also showed P450-content-dependent xanthotoxin depletion, whereas no detectable xanthotoxin metabolism was observed for HassCYP6AN1. These findings establish CYP6AN1 as a component of the capsaicin-metabolizing repertoire of both species and reveal substantial divergence between the orthologs in transcript organization, expression regulation, catalytic activity, and detectable substrate range.

Salivary secretions of herbivorous insects contain proteins that modulate plant defence and facilitate herbivory. Despite the broad host range of Spodoptera frugiperda, a major agricultural pest, its salivary molecular arsenal involved in interactions with different host plants remains poorly understood. In particular, the salivary proteins induced during feeding on different host plants and their potential interactions with plant immune components remain largely unexplored. To address this gap, we generated salivary gland transcriptomes from larvae reared on an artificial diet as well as larvae fed on tomato or chickpea plants. Comparative transcriptomic analysis identified salivary genes that were differentially expressed in response to plant feeding compared with the artificial diet. The encoded proteins were subsequently analysed using a secretory protein prediction pipeline to identify host-induced putatively secreted proteins with potential effector functions. Candidate salivary effectors were further investigated using large-scale in silico protein-protein interaction analyses with AlphaPulldown to predict their interactions with immune-pathway associated proteins of tomato and chickpea. This analysis identified multiple putative salivary effector candidates whose expression was induced by plants feeding, with distinct candidate repertoires associated with tomato and chickpea. Predicted interactions between these candidates and plant immune-associated proteins further identified potential host targets. Together, these findings suggest that S. frugiperda may adjust its salivary molecular repertoire in response to the host plant and provide a transcriptome-wide framework for validating effector-target interactions and elucidating the molecular mechanisms underlying S. frugiperda-plant interactions.

The global expansion of Black Soldier Fly (BSF), Hermetia illucens (L.), production systems for organic waste management has increased the need to better understand its reproductive biology in order to optimize mass-rearing programs. In this study, we macroscopically characterized chronological morphological changes in the internal genitalia of adult H. illucens reared on a sustainable alternative larval diet based on coffee pulp and corn bran. Morphological assessments and dissections were conducted on female and male reproductive tracts at 3, 6, and 9 days after adult emergence. Overall, the general organization of both reproductive systems was consistent with previous descriptions. A notable observation was the presence of a tripartite fertilization chamber in females, composed of three distinct compartments apparently associated with the three spermathecae. The functional significance of this anatomical organization remains to be determined. Females showed progressively advanced ovarian development and reached the clearest morphological indicators of reproductive maturity at 9 days, while males showed the greatest testicular distention and opacity at the same age. Compared with maturation times reported in previous studies using conventional larval diets, these observations suggest a later pattern of reproductive maturation under the coffee pulp-based diet. The observed differences may be associated with the nutritional composition and carbohydrate-to-protein balance of the larval diet. These results provide chronological and iconographic information that may contribute to the optimization of laboratory rearing protocols and the use of coffee by-products in H. illucens bioconversion systems.

Beech leaf disease (BLD), caused by the migratory plant pathogenic nematode, Litylenchus crenatae (LC, Anguinidae) is presently one of the most concerning forest diseases in the United States. BLD has spread rapidly across the landscape and is currently found in 15 U.S. states and Ontario, Canadian, making monitoring a top priority. Here, we report on the development and testing of a probe-based qPCR detection assay that integrates previously reported LC-specific primers with a newly designed probe, enabling sensitive and reproducible quantification of nematodes in plant and non-plant matrices. This assay exhibited strong in silico and in planta specificity and high quantitative performance (R2 = 0.988-0.996), with amplification efficiencies of 90.0-96.8%. The assay also performed consistently on LC-spiked spore trap membranes used to monitor the fungal aerobiome, despite matrix-associated shifts in amplification efficiency. These results support the utility of the assay for monitoring and surveillance. The reliability was further evaluated by two independent diagnostic laboratories, demonstrating high inter-laboratory concordance in detection and strong agreement in relative quantification. The analytical sensitivity and reproducible performance of the assay align with key validation principles outlined by the APS Diagnostic Assay Validation Network (DAVN) and support its application as a molecular tool in experimental, diagnostic, and surveillance contexts, with important implications for national and international LC monitoring and disease management.

Personal insect repellents can offer an effective means of preventing mosquito bites. Despite a wide variety of products that claim to repel mosquitoes, relatively few studies have systematically compared their performance through standardized tests. In Australia, chemical-based repellents must be registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA); however, many unregistered products with unverified effectiveness remain commercially available. Here, we tested 55 insect repellents and 5 non-repellent perfumes and deodorants sold in Australia for their protection against Aedes aegypti mosquito landings (as a proxy for bites) using arm-in-cage assays across eight human subjects. We tested 43 topical repellents (containing 18 different primary active ingredients), four wristbands, three clothing stickers, three ultrasonic devices, one garment, one repellent applied to fabric, two perfumes, two deodorants and one antiperspirant. Thirteen repellents, including all wristbands, stickers and ultrasonic devices did not provide complete protection against mosquito landings for any human subject, while a further sixteen provided complete protection for 1 hr or less on average. Repellents containing DEET, oil of lemon eucalyptus, picaridin and IR3535 as the primary active ingredient were the only products that provided more than 2 hours of complete protection, but with significant variation among products with the same active ingredient. Only 7/30 essential oil-based topical repellents and perfumes provided complete protection for greater than 1 hr. Nearly half (25/52) of the repellents subject to registration with the APVMA were unregistered despite being advertised or labelled as mosquito repellents, and these tended to be less effective than registered products. Only 5/28 repellents met or exceeded their claimed protection time. This study highlights the prevalence of unregistered and ineffective mosquito repellents on the Australian market while providing evidence for products and active ingredients that do protect against mosquito bites under laboratory conditions.

Western flower thrips (WFTs) are critical vectors of tomato spotted wilt virus (TSWV), transmitting it via a circulative-propagative cycle. The insect-virus relationship is unusual in that only larvae can acquire the virus for transmission to plants to occur. During the larval stage, the virus circulates and replicates within many organs, reaching the salivary glands before the insect pupates, and remaining in infected organs when the insect becomes an adult. The virus continues to replicate in the salivary glands of adult insects, after which it is inoculated into plants via saliva during feeding. Understanding the interactions between TSWV and the WFT salivary glands is critical to furthering investigations of TSWV inoculation and efforts to block the spread of this devastating plant virus. Here, we document transcriptomic changes associated with TSWV infection of the salivary glands of adults (males and females) and second instar larvae. Gene sets enriched in adult male, female, and larval genes revealed a core set of genes associated with WFT salivary glands, as well as genes that differed between sexes and between adults and larvae. The transcriptome response to TSWV infection was higher in larvae (second instar in this study) than in adults, with nearly a 10x increase in differentially expressed genes. We hypothesize this occurred because larvae efficiently acquire the virus and the virus first enters the SGs at the L2 stage, whereas adult SGs are infected only if acquisition occurred in the larval stage. Thus, assessment of larvae detects responses to the early stages of infection, while assessment of adults detects responses to the later stages of infection. Similarly, functional changes in larval salivary glands were more diverse, with significant transcriptome differences associated with growth and development in this tissue during infection. Lastly, a comparative analysis of changes in a published SG proteome revealed a correlation between transcript and protein levels during infection, but little overlap between significant TSWV-responsive transcripts and proteins. These studies provide critical insight into the molecular changes associated with the first breach of the SGs in larvae by TSWV, revealing a markedly different transcriptomic response compared to that in adults.

Indomethacin and temperature shocks are both widely used to induce ephyra production in Cassiopea polyps, yet the combined effect of these stimuli on strobilation rate, ephyra viability, and polyp survivorship has not been systematically examined. We designed a full factorial experiment crossing five indomethacin concentrations (0, 10, 25, 50, and 75 {micro}M) with four temperature treatments (22, 25, 28, and 31{degrees}C) across three independent experimental trials, exposing a total of 288 individual Cassiopea xamachana polyps for 29 days. Overall, 207 of 288 polyps (71.9%) released at least one ephyra. Temperature was the stronger predictor of strobilation: higher temperatures substantially increased the probability of producing a healthy ephyra (log-odds: +0.327 per {degrees}C; {chi}{superscript 2} p = 6.5 x 10-5), while indomethacin had a smaller but significant positive effect (log-odds: +0.024 per {micro}M; {chi}{superscript 2} p = 0.035). The two stimuli acted independently without significant interaction on healthy ephyra production ({chi}{superscript 2} p = 0.87), although their interaction on total ephyra production (including unhealthy releases) was significant ({chi}{superscript 2} p = 1.0 x 10-9). Notably, low indomethacin concentrations (10 and 25 {micro}M) significantly increased the proportion of unhealthy ephyrae relative to seawater controls (paired t-tests: p = 0.035 and p = 0.006, respectively), while higher concentrations (50-75 {micro}M) did not. Polyp survivorship declined significantly at 28{degrees}C and 31{degrees}C but was unaffected by indomethacin. Trial replicate was the most statistically significant predictor of every outcome measured with the third trial producing near-universal strobilation but zero viable ephyrae, a result of an unidentified perturbation. These results indicate that temperature elevation to 28-31{degrees}C is the most reliable induction strategy for C. xamachana and that low indomethacin concentrations should be avoided when ephyra quality is paramount. We also note that cryptic batch-level variables can overwhelm controlled factors and should be addressed in future experimental designs.

Feathers incorporated into bird nests are thought to provide multiple benefits, including thermal insulation and protection against nest-dwelling ectoparasites. For instance, in Swallows, it has been suggested that feathers influence infestations by Protocalliphora blow flies either by acting as a physical barrier between larvae and nestlings or through chemical compounds associated with preen oil. However, empirical evidence for an antiparasitic effect of feathers remains equivocal. Using 1,100 naturally infested Tree Swallow (Tachycineta bicolor) nests collected from a nest-box study system monitored in southern Quebec, Canada, between 2004 and 2018, we tested whether nest mass and feather abundance influenced hematophagous ectoparasites (Protocalliphora spp.) loads. We further assessed whether feather abundance directly affected body size using measurements of 1,513 P. sialia puparia, and emergence success using data from 961 Protocalliphora spp. puparia. Nest mass was positively associated with feather abundance, and both variables showed very weak positive relationships with parasite abundance. Feather abundance was unrelated to puparium size nor parasite emergence success. Our results provide no support for an anti-parasitic effect of feather lining within Tree Swallow nests. Using one of the largest datasets assembled to date on feather-lined nests and avian blow flies, we found no evidence that feather abundance impairs Protocalliphora density, development or emergence success. However, our findings do not preclude potential effects of feathers on other ectoparasites or microorganisms with different life histories. Future studies simultaneously monitoring multiple parasite taxa (such as fleas, mites, or bacteria) may therefore be needed to fully evaluate the ecological consequences of feather lining within avian nests.

Morphological variation in insects can indicate responses to habitat change and land use intensification, with potential consequences for trophic interactions. In insect host-parasitoid systems, host body is often a key determinant of offspring development and emergence success, as well as parasitoid host-selection behavior. Yet, most studies in agricultural landscapes have focused on size variation in crop-associated insects (i.e.: pests, pollinators and enemies), leaving those relying on non-crop resources largely unexplored. Here, we investigated how agroenvironmental contexts and trophic resource availability influence puparial size in Protocalliphora sialia (Diptera: Calliphoridae), an obligate hematophagous ectoparasite of Tree Swallow (Tachycineta bicolor) nestlings. We further tested whether puparial size affects emergence probability and risk of parasitoidism by Nasonia spp. (Hymenoptera: Pteromalidae) jewel wasps. Using 1,513 P. sialia puparia from 88 nests within a nest-box monitoring system spanning a 10,200-km^2 east-west intensification gradient in southern Quebec, Canada, we evaluated how agrointensive contexts, avian host availability, and ectoparasite densities influence puparial size, parasitoidism risk, and emergence success. The agricultural context appears to shape puparial size through survival biases and/or altered growth rates. In agroextensive contexts (i.e.: pastures, forages with high tree cover), where Protocalliphora are more numerous, P. sialia puparia were smaller and exhibited greater size variation. Conversely, in agrointensive environments (maize and soybeans monocultures with higher doses of pesticides), where Protocalliphora are fewer, small individuals were underrepresented, suggesting a selective mortality in P. sialia population. However, puparial size explained less than 10% of the variation in emergence or parasitism, likely reflecting consistently high parasitic pressure from Nasonia wasps, which infested 50-90% of puparia, depending on site and year. Our findings highlight the importance of selective mortality in structuring trait distributions and modulating multi-trophic interactions in human-modified landscapes.

As a specialist herbivore, koalas rely on their gut microbiomes to help digest their toxic and fibrous diet of Eucalyptus leaves. Without these critical microbes, koalas may not be able to obtain the nutrients and energy they need to survive. As such, a large proportion of koalas that undergo rehabilitation for chlamydiosis develop gut dysbiosis from the antibiotic treatment and are either euthanized or die. Here we aimed to modify previously developed fresh faecal inoculation capsules for an extended shelf-life such that they could be applied in a clinical setting to prevent or treat gut dysbiosis. Using 16S rRNA gene amplicon sequencing we demonstrated that air-drying faecal material leads to an overgrowth of facultative anaerobes, whereas lyophilised material retains a similar microbial composition to fresh material. Initial survival of koala faecal microbes as assessed by live/dead staining combined with microscopy was high after lyophilisation regardless of which excipient was used, except for 20% glycerol that resulted in ~15% lower survival than other treatments. Lyophilised fine particles extracted from koala faeces and packaged into acid-resistant capsules maintained their original microbial composition and had high microbial survival over a year, regardless of the excipient used. Dry-fill, single-layer capsules maintained integrity after 10 hrs in synthetic koala stomach acid. These capsules may be useful in adapting the gut microbiomes of koalas to novel diets e.g. during translocations. However, attempts to apply the capsules in the clinical setting were unsuccessful due to unanticipated difficulties in administrating the capsules to sick koalas.

The convergent lady beetle Hippodamia convergens is widespread in the Americas and considered an important beneficial insect due to its use in pest control. Early work on this species characterized the beetles as freeze-avoidant (freeze-intolerant), suggesting they survive low winter temperatures by physiologically preventing ice formation to temperatures as low as -15{degrees}C. Here, we show that H. convergens can be freeze-tolerant if ice formation occurs at relatively high temperatures. There was 100% survival following inoculative freezing at -0.5{degrees}C and exposure to -3{degrees}C for 20 hours, as well as freezing that spontaneously occurred in fed beetles exposed to -4{degrees}C for 4 hours. Males exposed to 0{degrees}C or -4{degrees}C for 4 hours had similar mating behaviours (latency to first mating, copulation duration) as control beetles exposed to 4{degrees}C, although sample sizes were too small to determine whether freezing itself had an effect on these behaviours. Several putative cryoprotectants were detected in fat body tissue of H. convergens: glycerol, proline, trehalose, and myo-inositol - in order of abundance. Exposure to -3{degrees}C for 20 hours, whether frozen or unfrozen, did not statistically affect cryoprotectant accumulation, although there was a trend towards increased glycerol following freezing. This study is the first to describe inoculative freeze tolerance in a lady beetle and establishes a baseline for future studies that examine the mechanisms underlying this freeze tolerance and the effects of freezing on reproductive behaviour. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=69 SRC="FIGDIR/small/744689v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@1c0382org.highwire.dtl.DTLVardef@12a5932org.highwire.dtl.DTLVardef@145f4adorg.highwire.dtl.DTLVardef@1c2cb22_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIHippodamia convergens can tolerate freezing at high subzero temperatures C_LIO_LIMating behaviour of males is normal after chilling or freezing C_LIO_LICryoprotectant accumulation may support overwintering survival C_LI

The ecological and economic threat posed by invasive pests demands proactive mitigation. Species distribution models (SDMs) are widely used in efforts to predict where invasive species might spread after introduction, though such models face several limitations. Among these is the unrealistic assumption of niche uniformity throughout a species' range. This has led to interest in developing SDMs that explicitly account for local adaptation, though few methods have achieved this in a way that confidently separates local adaptation from population structure. Here we develop and implement a sequential SDM approach that incorporates experimentally verified associations between genotype, phenotype, and environment to forecast establishment risk in a major agricultural pest. We leverage genomic data from 738 individuals to characterize the geographic distribution of alleles at a major-effect locus for cold tolerance (tret1) in Helicoverpa armigera, an invasive crop pest of major economic concern in North America. We demonstrate that a recently detected North American population carries a cold-adapted tret1 allele, which has likely contributed to its persistence. We quantify the contribution of cold-adapted tret1 to the potential invasive range of H. armigera in North America under current and future climate scenarios. We find that cold-adapted tret1 may dramatically expand the potential range of H. armigera, and that potential future range expansion is likely to be driven primarily by cold-adapted individuals. Our results highlight the importance of accounting for intraspecific variation in invasive species risk assessments and management strategies.

Wildflower plantings are an important conservation measure for supporting wild bee diversity. They aim to enhance floral resources for nutrition, but do not explicitly consider that bees also require suitable nesting and overwintering resources. Wildflower plantings may provide nesting habitat for ground-nesting bees, but the effects of soil management, e.g. ploughing, on ground-nesting bees are hardly known. To study how ploughing and age of wildflower plantings affect ground-nesting bees, we sampled bees on ploughed and unploughed wildflower plantings aged 0-4 years. We used emergence traps to sample bees directly after emergence from the ground, allowing inference on nest numbers. We found that ploughing and wildflower planting age negatively affected overwintering bee nest numbers. Nesting peaked in the year of wildflower planting establishment and declined thereafter, indicating lower habitat suitability at later successional stages. Annual ploughing caused the greatest reduction in nest numbers (-72 %), providing evidence for an ecological trap.

Spodoptera frugiperda is one of the most important agronomical pests due to its migratory capacity and broad host range. Since it is resistant to several insecticides, novel control strategies are being explored to control it. In this way, Spodoptera frugiperda Multiple Nucleopolyhedrovirus, a natural pathogen, has been proposed for its biocontrol. In this work, we performed a small RNA-seq on uninfected larvae and larvae infected with SfMNPV to identify expressed miRNA, characterize them, and identify differentially expressed (DE) miRNA in the infected condition. We identified several known and putative novel miRNAs, some of which are encoded in multiple copies and may be expressed within miRNA clusters. We also found 13 DE miRNA, most of them previously reported, two of them are putative novel miRNAs identified in this work. We predicted miRNA targets and found that their putative biological role could be related with processes relevant to the infection such as proliferative and apoptotic pathways, cell cycle regulation, autophagy, DNA damage response (DDR), vesicle transport, cytoskeleton remodelling, JAK/STAT and Toll signaling pathway, and immune response activation, among others. Moreover, we observed that several of the putative targets were hub genes in a predicted protein - protein interaction network. Finally, we found DE miRNA putatively associated with the regulation of viral gene expression, suggesting they might have a role in modulating the infection. Our results contribute to better understanding the miRNA landscape in S. frugiperda, and their putative role upon SfMNPV infection.

Experimental hut trials (EHTs) are WHO-recommended for the entomological evaluation of insecticide-treated nets (ITNs), but several hut designs are in operational use, and structural differences between them may confound efficacy predictions and limit cross-site comparability. We developed a Bayesian hierarchical framework comprising a host-seeking model, which jointly estimates biting deterrence and preprandial mortality while accounting for night-to-night variation and overdispersion, and a postprandial mortality model, which expresses hut and net effects as hazard ratios through a complementary log-log link. We applied it to a comparative trial of four hut designs (East African, West African, Ifakara and Rapley) conducted at a single site in Tanzania, evaluating eight ITNs when new and after twenty washes. Posterior estimates parameterise a vectorial capacity framework to predict reductions in transmission potential. Hut design influenced baseline mosquito behaviour and all three modes of action. Relative to the Rapley reference, baseline feeding rates were substantially lower in the East African and West African huts and closer to Rapley in the Ifakara hut. Preprandial mortality was amplified in the Ifakara hut. Comparing to previous analysis provides evidence that combining mortality before and after feeding into a single endpoint does not reliably reflect impact, supporting the decomposition of entomological outcomes into separate modes of action. Expressing modes of action as mechanism-specific parameters allows the estimates to be carried directly into transmission models. For every net, the predicted reduction in vectorial capacity was greatest in the Ifakara hut and smallest in the West African and Rapley huts. The effect of hut design on predicted impact exceeded that of washing the nets twenty times. Results indicate that the hut design under which trial data were collected should be considered when forecasting population-level effect.