The blue gum chalcid (Leptocybe invasa) is a serious invasive, galling insect pest of eucalypts grown outside Australia. Variability in resistance of species and genotypes of Eucalyptus to the pest is widely reported but without consideration of the influence of silviculture on the severity of galling. We assessed the variability of gall expression by 29 genotypes of E. camaldulensis by L. invasa in common nursery experiments and in 5 common garden arboreta planted in diverse climatic zones and soil types around Kenya. We quantified variation in growth and the concentrations of defensive chemical compounds (namely polyphenolic compounds) to assess possible genotype × environment interactions which we also relate to the climate of the parent seed trees in Australia. Generally, genotypes endemic to low latitude regions of Australia were more resistant to the pest while the concentration of quinic acid derivatives (QUIN) exhibited an interaction with arboretum location in Kenya. The concentration of QUIN in potted plants did not vary significantly with nitrogen supplementation. However, growth rates and total polyphenolic concentrations varied with arboretum location. Since QUIN, which have been previously shown to confer resistance against L. invasa, did not vary in different arboreta, resistant subspecies and genotypes of E. camaldulensis can be deployed in novel habitats and will not be galled. Our findings support the critical need to plant stock of known genotype(s) rather than planting stock grown from locally collected seed. This will require the establishment of eucalypt seed orchards if clonal production of planting stock is not possible.

Parasitoids play a key role in biological control, regulating pest populations in natural and agricultural ecosystems. Their efficiency depends on a thorough understanding of host–parasitoid interactions. Among these, the functional response, the relationship between parasitism rate and host density, plays a critical role. Despite a well-established background, challenges remain in experimental design, model selection, and parameter estimation for functional response analysis in parasitoids. This study aims to provide a practical guide to addressing these challenges. We outline key considerations in experimental design, including the selection of model organisms and initial host densities. For model selection, we present methods to differentiate between Type II and Type III functional responses, identifying the best-fitting models for parasitoids. In parameter estimation, we present an example demonstrating the application of functional response models for each type, including parameter estimation to guide model choice. Additionally, we provide equations and code based on published data to facilitate parameter comparisons. This guide provides a structured framework for experimental design, parameter estimation, and model selection in functional response studies, which is adaptable to various host–parasitoid interactions. By enhancing methodological rigour, we aim to support researchers in improving the precision and applicability of functional response analyses in parasitoid research.

The impact of host size and sex on parasitism by the Irish strain of the hymenopteran parasitoid Microctonus aethiopoides Loan was investigated in the laboratory and in the field. Field data showed that while there was a large overlap, female adults of the target host Sitona obsoletus Gmelin averaged heavier weights than males (7.0 mg vs. 5.4 mg, P < 0.001). Male and female adult weights varied monthly: this was likely due to the emergence of a new weevil generation and environmental factors such as rainfall. While host sex and weight had no obvious impact on overall parasitism rates in S. obsoletus in the field, a no-choice cage study revealed that M. aethiopoides had lower parasitism rates (74% vs. 91%, P < 0.001) in larger weevils compared to small weevils. Additionally, parasitoid larval development was faster in female hosts compared to males, irrespective of size. While undetectable in field observations, differential development rates would enhance Irish M. aethiopoides population resilience. By breaking the previous generation synchrony, the population would be less vulnerable to being decimated by a single adverse event.

This study investigates the gut microbiota of newly emerged adult females and males of five economically important Anastrepha species (Tephritidae) – A. ludens, A. obliqua, A. serpentina, A. striata, and A. fraterculus – by analyzing 16S rRNA amplicon sequences from 36 samples collected from ecologically relevant fruit hosts and locations in Mexico. We chose to concentrate only on newly emerged adults to identify bacteria that females could potentially transmit vertically to progeny via oviposition, a topic that remains poorly studied. Results revealed that Proteobacteria dominated the microbiota in all species, but substantial variation was observed in genus-level composition. Differentially abundant genera included Enterobacter, Gluconobacter, Tatumella, Providencia, Ochrobactrum, Siccibacter, Sphingobacterium, and Sphingobium. Significant differences in alpha diversity were observed between species, particularly between A. obliqua and A. striata, and between A. obliqua and A. serpentina based on the Shannon index. Anastrepha ludens, A. obliqua, and A. striata males exhibited higher species richness than females, although these differences were not statistically significant within individual species likely due to limited sample size. Interestingly, across all species, significant differences in microbiota composition were observed between males and females. Our findings suggest that morphological, physiological (i.e., metamorphosis) and ecological factors, such as possible gut structural differences and host fruit preferences, may influence the composition of the gut microbiota, potentially affecting the ecological adaptability and pest behavior of these flies.

Anaesthesia methods play a crucial role in ensuring the integrity of the animal during experimental studies. This study investigates the impact of two anaesthesia methods, CO₂ and cold treatment, on an insect antennal response to synthetic alarm pheromone compounds. Adult worker hornets were anesthetised, and their antennae excised and tested using an electroantennography set-up with controlled stimulation of alarm pheromone components. Results showed that CO₂-anesthetised hornets exhibited robust antennal responses, while cold-anesthetised individuals displayed none. This result suggests that freezing may impair the functionality of olfactory receptors. In contrast, CO₂ anaesthesia preserves receptor integrity, offering reliable and interpretable results. This study highlights the importance of selecting appropriate anaesthesia techniques to avoid artefacts in insect sensory physiology research and underscores the ecological relevance of studying Vespa velutina nigrithorax alarm signalling.

Lygus hesperus is an economically important pest of many crops. An effective monitoring method for the early detection of L. hesperus could improve its management. A recently developed pheromone lure has been shown to attract L. hesperus males, however, fewer males were captured than expected. It is unknown whether this was an effect of pheromone responsiveness or the type of trap used. Thus, we compared the efficacy of the previously used white delta sticky traps to red cylindrical sticky traps in strawberry fields in California and cotton fields in Arizona. Collections were made 1 and 2 weeks after trap deployment. In strawberry, pheromone baited traps captured more L. hesperus males than unbaited traps. More males were collected from baited red cylindrical sticky traps compared with either type of unbaited trap. In cotton, baited red cylindrical traps captured more males than unbaited traps after 1 week of field exposure, but not after 2 weeks of deployment. Overall, red cylindrical traps caught more L. hesperus males than white delta traps. Diminished trap captures during the second week of monitoring may be attributed to high temperatures in cotton that likely shortened the lure’s longevity and windy conditions in both strawberry and cotton that may have decreased the effectiveness of the trap’s adhesive. Additional work to clarify the lure’s field longevity and distinguish various elements of trap design (e.g. colour, adhesive, and shape) may further increase the operational effectiveness of pheromone-baited traps for L. hesperus.

Agricultural intensification has a strong impact on arthropod diversity, yet predators such as spiders provide key ecosystem services through natural pest regulation. Understanding how local and landscape factors shape spider assemblages throughout the season is essential for designing effective agro-ecological infrastructures that can sustain their services in crop systems. We investigated ground-dwelling spider communities in Belgian winter cereal fields and their margins. Pitfall traps were used across seasons to assess the effects of habitat (field vs. margin), surrounding crop cover, and seasonal dynamics on spider richness, activity-density, and community structure. Results show that spider activity-densities were consistently higher in margins than in fields, whereas species richness showed no significant differences between these habitats. Significant seasonal variations were detected on both spider richness and abundance. The landscape effect of the annual crop cover was context dependent, showing seasonal and species-specific patterns and even positive associations in autumn. Seasonal shifts also reflected life stage and sex-specific phenologies. This study reveals that spider communities in Belgian cereal systems are shaped by interacting local, landscape, and seasonal factors. Margins mainly act as refuges that bolster spider numbers rather than species pools, while the influence of the surrounding landscape depends on the season and the species identity. These findings highlight the need to incorporate temporal and biological context when designing margins and other agro-ecological infrastructures to support natural pest regulation providers such as spiders.

Alfalfa is a widely cultivated forage crop with high nutritional value, and it relies heavily on pollinators for successful reproduction owing to its keel petal structure. Numerous studies have shown the differences in pollinator diversity at different landscapes and/or regions, subsequently impacting plant reproduction. However, there is still insufficient evidence on variation in pollinator diversity at different sites with different landscapes and its effects on alfalfa reproduction. In this study, we investigated the diversity and abundance of floral visitors, and their impacts on alfalfa seed yield, across three sites represented by different landscapes, i.e. urban (Gongzhuling), semi-natural grassland (Changling), and farmland (Harbin) in north-eastern China. Our results showed that the diversity and abundance of all visitors, including bees in Changling were significantly higher than those of the other two sites. Changes in visitor diversity and abundance of alfalfa were closely related to climate variables, with positive effects of air temperature, and complex effects of precipitation. Meanwhile, the differences in pollinators may also be attributed to landscape types due to different habitat heterogeneity. Alfalfa seed yield in Changling was also significantly higher than that in the other two sites. Among these factors, air temperature, and diversity of floral visitors, particularly bees were positively related to alfalfa seed yield, indicating that pollinators combined with climate have an important contribution to changes in alfalfa seed yield. The findings from this study emphasise the importance of conserving pollinators to sustain and even enhance alfalfa yields, especially in the context of climate change and alterations in landscape types.

Soybean (Glycine max L.) is a globally significant crop, valued for its high protein content and vegetable oil, which serve vital roles in both food and industrial applications. However, the soybean bruchid (Callosobruchus chinensis L.) infests soybean seeds in Ethiopia, especially during storage, and this infestation threatens their post-harvest quality. This study evaluated the resistance of 50 soybean genotypes against C. chinensis by analysing oviposition rates, adult emergence, and seed weight loss. Results revealed substantial genetic variation among genotypes for their resistance. Two genotypes (G-44 and G-38) exhibited strong resistance, and 16 showed moderate resistance, while the rest were susceptible. The vulnerability of released cultivars in Ethiopia underscores the critical importance of integrating bruchid resistance into future breeding programmes. Addressing this challenge is critical for sustaining soybean productivity and ensuring post-harvest seed integrity in bruchid-prone regions.

The fungus Beauveria bassiana (Unioeste 76) was tested against the soybean pest Euschistus heros in laboratory, greenhouse, and field. In the laboratory, insects were sprayed with pure conidia (TC) suspended in distilled water or in an oil dispersion formulation (OD; vegetable oil) at a concentration of 109 conidia/mL. The UV-B radiation and heat tolerance of the conidia were also assessed. After 12 days, the mortality rates in the laboratory were 70% for the TC treatment and 80% for the OD treatment. In the greenhouse pre-infestation bioassay, which used soybean plants in cages, the fungal treatments resulted in 52% and 47% mortality for the TC and OD formulations, respectively. In the post-infestation bioassay, both fungal treatments caused 83% mortality. In the field trial conducted on soybean plots (14 × 18 m), the treatments included: (i) biological: OD (109 conidia/mL); (ii) chemical insecticide; (iii) biological + chemical, all applied at 150 L/ha. Insect numbers were evaluated using beating-sheet sampling. In the final population sample, the biological treatment showed a population density similar to the chemical treatment (0.94 and 0.83 insects/m, respectively), both below the economic threshold. Conidia tolerance to UV-B radiation was similar across both treatments, but conidia in oil were less tolerant to heat. These results suggest that strategically combining both approaches (B. bassiana with chemical insecticides), with careful consideration of application intervals, could provide a sustainable and effective method for managing natural populations of E. heros.

The Hyphantria cunea (Drury) is a highly polyphagous invasive pest that has become widespread and destructive in China. Although sex pheromone components of H. cunea have been identified, the weak field attraction of synthetic sex pheromone has hindered the application of sex pheromone-based lures in efficient monitoring and management of this pest. In this study, the electroantennographic (EAG) and field responses of H. cunea male adults to three synthetic sex pheromone components, including Z9, Z12, Z15-18Ald (C18:Ald), Z3, Z6-9S,10 R-epoxy-21Hy (C21-2Epo), and 1, Z3, Z6-9S,10 R-epoxy-21Hy (C21-3Epo), were evaluated. Male antennae exhibited significant dose-dependent response to three individual components and a ternary mixtures. The younger and virgin male moths showed stronger electrophysiological activity to synthetic compounds, whereas sensitivity decreased significantly after mating. Among the three components, C21-3Epo elicited the strongest antennal responses. Field trapping revealed that neither single compounds nor binary blends attracted males, whereas only the ternary blend of C18:3Ald, C21-2Epo, and C21-3Epo (ratio 8:1:1; 10 mg total load) effectively captured large numbers of males. In addition, the field trapping indicated that the green rubber septum functioned as a practical dispenser for synthetic pheromones. The Unitraps baited with the green rubber septum showed significantly higher trapping efficiency than cotton wicks, highlighting the septum as a promising dispenser for field deployment of synthetic sex pheromones. Finally, the green rubber septum baited with a ternary blend monitored the dynamics of H. cunea occurrence and detected that the emergence period overlapped with the commercially available synthetic lure. In general, the bioactivity of the synthetic sex pheromone of H. cunea was validated. It could effectively capture H. cunea male adults, be used to monitor and control H. cunea, and further be incorporated into the integrated pest management programme.

Drosophila suzukii is a significant pest of soft- and thin-skinned fruit crops. Synthetic pesticides remain the primary control method; however, their use raises concerns about insect resistance and harmful pesticide residues in produce. Methyl jasmonate (MeJA), a plant growth regulator in the jasmonate family, plays a key role in plant defence against herbivores and has been identified as a repellent for arthropods of medical and veterinary relevance. This study examined the effect of MeJA on D. suzukii female oviposition and adult behaviour using two-choice bioassays. In a two-choice cage, doses above 1287.5 µg/filter paper deterred D. suzukii females from oviposition by more than 90% on artificial fruits. Using a two-choice planar olfactometer, MeJA also repelled both sexes with median repellent dose (RD50) values of 55.24 µg/filter paper for females, 55.03 µg/filter paper for males, and 55.14 µg/filter paper for total adults. Interestingly, MeJA demonstrated a dose-dependent dual effect: at 309.0 µg/filter paper, it functioned as a bio-repellent, while lower doses (3.86–15.45 µg/filter paper) acted as an attractant. This dual effect suggests that MeJA could serve as both a repellent and an attractant depending on its dose, with potential applications as a lure in traps.

This study evaluated the sublethal and demographic effects of deltamethrin, cypermethrin, and chlorantraniliprole on the bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae). The age–stage, two-sex life table model was used to assess population parameters following exposure to LC₃₀, LC₄₀, and LC₅₀ concentrations of each insecticide under laboratory conditions. Sublethal treatments significantly affected developmental time, longevity, fecundity, and overall population fitness. The total pre-adult duration increased from 11.66 days in the control to 18.07 days under deltamethrin LC₅₀ exposure. Adult longevity decreased from 18.06 days in the control to 11.52, 13.92, and 14.18 days for deltamethrin, cypermethrin, and chlorantraniliprole LC₅₀, respectively. Fecundity was severely reduced, declining from 57.69 nymphs per female in the control to 10.63, 21.57, and 28.92 at LC₅₀ of the respective insecticides. Demographic analysis showed that the intrinsic rate of increase (r) and finite rate of increase (λ) significantly decreased with increasing concentration. The control population exhibited r = 0.346 day−1 and λ = 1.413 day−1, whereas these values dropped to 0.097 and 1.101 under deltamethrin LC₅₀, 0.165 and 1.179 under cypermethrin LC₅₀, and 0.198 and 1.219 under chlorantraniliprole LC₅₀. Conversely, mean generation time (T) increased from 11.66 to 18.07 days. Overall, deltamethrin caused the most severe demographic suppression, followed by cypermethrin and chlorantraniliprole. These findings demonstrate that sublethal insecticide exposure can markedly disrupt the life history and population growth of R. padi, underscoring the necessity of integrating sublethal effect evaluations into ecological risk assessment and IPM programs.

Insect immunology represents a critical component of circulatory physiology research. Considering the ecological significance of mantids and their predatory roles, this study investigated the types of hemocytes and their modulation by starvation, prey quality, and temperature in Hierodula tenuidentata and Empusa fasciata. This study also documents the presence of these two species in Semnan province, Iran for the first time, expanding our knowledge of their distribution. Field-collected oothecae were incubated under controlled conditions (temperature 25 ± 1°C, relative humidity 50%, and a photoperiod of 14:10 light:dark hours) until nymphal emergence. Following hemolymph extraction and staining with Giemsa solution, four hemocyte types – prohemocytes, plasmatocytes, granulocytes, and oenocytoids – were identified in both species; spherulocytes appeared exclusively in adult H. tenuidentata under a light microscope. Differential hemocyte counts revealed granulocytes as predominant in H. tenuidentata, whereas both granulocytes and plasmatocytes were abundant in E. fasciata across developmental stages. Prohemocytes were more abundant in the early-instar nymphs than in the late-instar nymphs of both mantids. Hemocyte density declined progressively with prolonged starvation, reaching a minimum after 4 days. The highest hemocyte concentrations were observed in mantids fed grasshoppers after 1 week, whereas markedly lower counts occurred with low-quality prey, such as Musca domestica L. (Diptera: Muscidae) and Lycaena sp. (Lepidoptera: Lycaenidae). Heat stress significantly elevated hemocyte density, whereas cold exposure induced substantial reductions in hemocyte density. Hemocyte fluctuations were more pronounced after 48 hours than after 24 hours. These findings suggest that short-term dietary deprivation, prey type, and thermal stress may rapidly alter immune profiles in H. tenuidentata and E. fasciata.

The immunomodulatory effects of Ziziphus jujuba Mill. fruit extracts were investigated using Galleria mellonella as an insect immune model. The expression of antimicrobial peptides, hemolin, phenoloxidase genes (PO-I and PO-II), and enzyme activity was measured in response to Candida albicans, silica beads, and Z. jujuba fruit extract. Responses were found to be stimulus- and time-dependent. Gallerimycin and galiomycin, key antimicrobial peptides, exhibited distinct expression patterns, with gallerimycin showing a more pronounced response to pathogens and beads. The Z. jujuba extract stimulated an early but balanced immune activation, likely due to its bioactive compounds. Hemolin expression varied between larvae and haemocytes depending on the type and duration of the challenge, supporting its role in immune recognition and opsonisation. Phenoloxidase activity and gene expression were also enhanced, supporting their role in promoting melanisation processes. Docking analyses suggested that hemolin contributes to phenoloxidase activation by stabilising PO-I and interacting with the phenoloxidase-activating factor-1-like protein (PAP1). The findings suggest that Z. jujuba extract effectively modulates immune responses, promoting enhanced protection while maintaining immune balance. GC-MS analysis revealed multiple bioactive compounds potentially contributing to immune modulation. This study highlights the significant immunomodulatory effects of Z. jujuba fruit extract on the immune system of G. mellonella. The findings suggest its potential as a natural immunostimulant and warrant further investigation of the underlying molecular mechanisms and bioactive components.

Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) is one of the most serious pests of rice. The variations in phytoconstituents of rice cultivars (Miniket, Cottondora Sannalu, Gobindobhog, Swarna, and Tulaipanji) that led to differences in population growth of S. cerealella were studied. Fitness of the moth was approximated in terms of mean generation time (Tc), net reproductive rate (NRR or R0), intrinsic rate of population increase (rm), etc. Considering potential fecundity (Pf), growth rates, mortality coefficient (MC), and expected population size in the second generation (PF2), we classified the susceptibility of the rice cultivars to S. cerealella in the order as M > C > G > S > T. This was despite the higher concentrations of all the tested primary metabolites (PMs) in C and T. The least susceptibility of T and lower susceptibility of C than M can be attributed to their higher levels of secondary metabolites (SMs). M was highly susceptible due to its lowest SM content and sufficient levels of PMs. Now, G and S contained lower amounts of SMs, but they were moderately susceptible owing to the lower PM content. This emphasises the role of SMs, such as phenols, flavonoids, tannins, saponins, alkaloids, phytates, and oxalates, in determining the susceptibility of crop cultivars. Although none of the rice cultivars were entirely resistant, it can be stated that Miniket requires more protection measures against S. cerealella during storage than the others.

This study presents the first record of Miyalachnus sorini Kanturski & Lee, 2024 (Aphididae: Lachninae) in South Korea, thereby extending its known distribution beyond Japan and identifying a new host plant, Prunus sargentii (Rosaceae). We describe diagnostic morphological traits across multiple life stages and compare them with those of Japanese populations. Comparative analyses with Japanese populations demonstrated consistent morphological differentiation, notably elevated ratios of the ultimate rostral segment to antennal segments across multiple morphs in the Korean population, indicating potential ecological adaptation. DNA barcoding using the mitochondrial cytochrome c oxidase I gene revealed low intraspecific divergence (average 0.2%) and interspecific divergence (average 10.5%) between Miyalachnus sp. and M. sorini. Haplotype analysis was performed to investigate the relationship between host plants and cryptic genetic diversity. These findings enhance our understanding of the morphological and genetic diversity of M. sorini and underscore the importance of monitoring its spread for informed pest management strategies.