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.

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.

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.

Oecleopsis sinicus (Jacobi, 1944) (Hemiptera: Cixiidae) is a serious phytophagous pest first recorded as an agricultural pest in China. This species has now expanded its distribution within its native Asian range, resulting in significant economic losses in agricultural production and posing potential threats to some important crops and vegetables in many countries. To determine the intrinsic connection between climate change and the geographical expansion of this pest, an optimised MaxEnt model was applied to examine the predicted geographic range of O. sinicus under current and projected climate scenarios (2041–2060, 2061–2080, and 2081–2100), using CMIP6 projections (SSP126 and SSP585). The model showed high predictive accuracy (area under the curve (AUC) = 0.940). By the end of the 21st century (2081–2100), MaxEnt modelling forecasts a significant expansion of suitable habitat for O. sinicus under both climate scenarios. The total suitable area is projected to be 511.7527 × 10⁴ km2 under the SSP126 scenario and 570.9165 × 10⁴ km2 under the SSP585 scenario. This represents an increase of 44.59% and 49.7%, respectively, compared to the present. The distribution of this species is predicted to shift and expand northwestward across Asia under all scenarios, with the most pronounced increase projected for East Asia under SSP585 (85.1% expansion during 2041–2060). This study can provide a foundation for pest monitoring, early warning measures, and quarantine strategies in high-risk countries.

Host plant adaptability drives the ecological plasticity and global expansion of Spodoptera frugiperda (J.E. Smith, 1797). However, the mechanisms underlying the long-term adaptation of its maize ecotype to alternative hosts remain unclear, hindering host-shift risk predictions. We evaluated the host-shift risk of the maize ecotype of S. frugiperda across four generations of continuous rearing on maize (Zea mays L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.), and green bristlegrass (Setaria viridis (L.) P. Beauv.) by analyzing biological performance, feeding and oviposition behaviours feeding/oviposition preferences, and protective enzyme dynamics. Prolonged monophagous feeding significantly accelerated developmental cycles across generations. Wheat emerged as the most suitable host under laboratory conditions, shortening immature stages to 22.86 d (F3) and increasing pupal weight by 40.7%, whereas S. viridis resulted in the lowest fitness, with 32.31-d immature period and 59.33% survival rate (F4). Larval feeding and adult oviposition preferences consistently aligned with multigenerational feeding on the same host. Enzymatic profiling showed maize-fed larvae maintained the lowest catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), whereas S. viridis-reared larvae exhibited peak enzyme activities. Notably, adaptation to wheat was associated with reduced enzymatic stress responses, with CAT and POD activities decreasing by 21.8% and 17.5%, respectively, from F1 to F3, indicating physiological acclimation. These findings suggest that multigenerational feeding can enhance population fitness and promote host preference through physiological and behavioural plasticity. This laboratory study indicates the potential for the maize ecotype to pose threat to wheat production, providing a basis for managing.

The classification of the species in the genus Actias Leach, 1815 (Lepidoptera: Saturniidae) is challenging because many species have a highly similar morphology, while differences in database classification standards also provoke identification problems. To help resolve these issues, we conducted an integrative analysis of 741 cytochrome oxidase subunit I (COI) barcode sequences available by combining phylogenetic reconstruction, population genetic (Fst) metrics, and biogeographic data. This approach delineated 44 molecular operational taxonomic units (MOTUs) and established a genus-specific, empirical genetic distance threshold of 2.05% from a baseline of 29 morphologically validated MOTUs. These 29 MOTUs/morphospecies were then utilized to assess the interspecific genetic distance gap of this genus and further used as the species-level genetic distance to delimit the remaining morphospecies. Applying this multi-evidence framework allowed us to propose a significant re-evaluation of species boundaries, including several taxonomic reclassifications, and to generate the molecular inventory for Actias. Our study illustrates the power of an integrated molecular approach to resolve complex taxonomic issues and provides a robust, data-driven foundation for future research on Actias.

Native boxwood across Europe has been destroyed by the invasive moth Cydalima perspectalis. To date, climatic conditions and natural enemies have not been able to contain the pests. Increases in temperature due to climate change (CC) may affect insect development and voltinism, with species-specific effects. Its spread across European countries indicates that the expansion of C. perspectalis is not limited by cold winters. However, in southern Europe, rising maximum temperatures can affect pests and their host plants. Despite this, the effects of high temperatures on herbivorous pests have been studied far less extensively than those of low temperatures. Our results show that elevated temperatures accelerate egg development but prolong larval development, reduce adult longevity and fertility, and substantially increase mortality across the egg, larval, and pupal stages. These findings indicate that spring–summer temperatures in the Mediterranean Basin are approaching the upper thermal limits of this species and that further warming is unlikely to facilitate its expansion in this region. Although high temperatures did not reduce diapause induction, they increased larval mortality, and field monitoring showed that altitude, more than thermal time, dominated the patterns of first-flight emergence. Habitat orientation (North or South) may further mediate pest–host coexistence. Overall, this study contributes to the literature by clarifying how this pest responds to the warming conditions associated with CC in southern Europe.

Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is an important agricultural biocontrol agent that preys on various soft-bodied insect pests. This study was carried out to evaluate the fitness parameters of bifenthrin-selected (Bifen-Sel) and unselected (Unsel) strains of C. carnea and their reciprocal crosses (C1 and C2) by using an age-stage and two-sex life table approach. After continuous selection with bifenthrin (44 generations), the Bifen-Sel strain of C. carnea developed a 9.55-fold resistance level when compared to that of the Unsel. Biological parameters, such as the pupal period, pre-adult duration, male and female longevity, adult pre-oviposition period, and oviposition period of the Bifen-Sel strain, all were significantly different from that of the Unsel strain and their crosses C1 and C2. The larval period, total pre-oviposition period, female ratio, reproductive female ratio, and fecundity of the Bifen-Sel strain were significantly different from those of the Unsel strain. Demographic parameters, including intrinsic rate (rm), finite rate (λ), net reproductive rate (R0), mean generation rate (T), and gross reproductive rate of the Bifen-Sel strain, were similar to those of the Unsel strain but significantly higher than those of the C1 and C2 crosses of C. carnea. Bifenthrin resistance was stable in the Bifen-Sel strain of C. carnea. These findings provide valuable insights into bifenthrin resistance dynamics in C. carnea as it resulted in no fitness cost and support its selective use under controlled conditions, while highlighting the need for future research on predation potential of this resistant strain under field conditions with bifenthrin applications.

Ferrisia dasylirii (Cockerell) (Hemiptera: Coccomorpha: Pseudococcidae) is a polyphagous mealybug species and native to North America, but has spread to Asia and Africa. In this study, we report F. dasylirii for the first time from China using an integrated taxonomy approach combining morphological characters and molecular analyses of the mitochondrial cytochrome oxidase subunit 1 gene. It was found on 12 tropical fruit species in Hainan Province: Annonaceae: Annona squamosa L. and A. squamosa ‘Purple’; Myrtaceae: Eugenia brasiliensis Lam. and Psidium guajava L.; Malvaceae: Theobroma cacao Linn.; Lecythidaceae: Lecythis pisonis Cambess.; Sapotaceae: Pouteria campechiana (Kunth) Baehni and P. sapota (Jacq.) H.E.Moore & Stearn; Rubiaceae: Coffea liberica W. Bull ex Hiern; Cunoniaceae: Davidsonia pruriens F. Muell; Arecaceae: Areca catechu Linn.; Musaceae: Musa nana Lour.; Malpighiaceae: Malpighia emarginata Sesse & Noc.ex DC.; and Phyllanthaceae: Phyllanthus emblica Linn. This record increases the known geographic range of F. dasylirii and underscores the importance of combined morphological and molecular approaches for accurate mealybug identification.