Temperature is an important environmental factor influencing the life-history traits of ectotherms. This study investigated the effects of larval-rearing temperature (21, 23, 25, and 27 °C) on the life-history traits and adult fitness of the fall webworm, Hyphantria cunea, an economically important invasive pest of China. With the increase in temperature during the larval stage, the larval developmental duration was significantly shortened, and the body mass was significantly increased, as was that of the body mass and size of pupae. The carbohydrate and lipid content of pupae significantly decreased with increasing larval-rearing temperature, whereas the protein content significantly increased. Adult body size and egg production increased significantly with increasing larval-rearing temperature, whereas there was no significant difference in egg diameter. These results indicate that H. cunea demonstrates life-history traits plasticity. In addition, the increase in fecundity would maintain a stable population size of H. cunea under higher temperatures. Such characteristics could enable H. cunea to spread to the more southern, warmer areas of China, posing an increased risk to the forestry industry in these regions.

Diapause, a survival strategy utilized by many insects under severe environmental conditions, can generate costs that potentially affect post-diapause development and reproduction. The willow leaf beetle, Plagiodera versicolora, overwinters as an adult. This study investigated the cold hardiness-hardiness and energy utilization of female P. versicolora, and their impact on post-diapause reproductive fitness. The supercooling point exhibited seasonal temperature variation, with the lowest points occurring in January and February, coinciding with the relatively lower ambient temperatures. Lipid content demonstrated a pronounced decline at the onset of diapause (from November to December) and stabilized from December to March. Glycogen content also showed a sharp decrease from November to January, subsequently stabilizing at relatively constant levels. In addition, trehalose content increased significantly when temperatures dropped (from November to January) and then decreased as temperatures rose (from January to March). There were no significant differences in the time from pairing to successful mating for post-diapause females compared with non-diapause females. However, mating duration and the pre-oviposition period for post-diapause individuals relative to non-diapause individuals increased, coupled with a reduction in the oviposition period, total number of eggs, number of egg clutches, and number of eggs per clutch; however, most importantly, there was no notable change in egg-hatching success. These results suggest that the cold-hardiness strategy of P. versicolora falls within the freeze-avoidance category, with energy usage predominantly reliant on lipids and carbohydrates during diapause initiation. Our findings also highlight that, although post-diapause females are capable of nutrient replenishment, the energetic demands of diapause result in considerable negative impacts on post-diapause female reproductive fitness.

The sycamore lace bug, Corythucha ciliata, a globally invasive pest that damages Platanus spp., harbors a bacterial microbiome that may help it adapt to different geographical environments. However, the geographical differentiation patterns of its bacterial community and the underlying driving mechanisms remain unclear. In this study, we standardized rearing of three C. ciliata populations (collected from Beijing, Lianyungang, and Nanjing) for three generations to reduce immediate environmental interference, then analyzed their bacterial communities via 16S rRNA gene amplicon sequencing. The principal coordinate analysis revealed a significant separation of the bacterial community in the Nanjing population, while the Beijing and Lianyungang populations were more similar. Bacterial alpha diversity followed the gradient of “Nanjing > Lianyungang > Beijing”, with the Nanjing population exhibiting significantly higher species richness and evenness than the Beijing population. All three populations shared core bacterial taxa (e.g., phyla Proteobacteria, Bacteroidota; genera Cardinium, Serratia), but their relative abundances differed significantly: Cardinium dominated the Beijing population (50.1%), Serratia dominated the Lianyungang population (45.86%), and the Nanjing population harbored unique dominant genera such as Sphingomonas. For the three target populations, monthly average temperature and wind speed were positively correlated with bacterial diversity, while latitude was negatively correlated (Pearson correlation coefficient: 0.6564 < |r| < 0.7010, p < 0.05). Core bacterial functions (e.g., substance transport) were conserved across populations, whereas differential functions (e.g., detoxification, lipid metabolism) were linked to geographical adaptation. This study confirms the climate-driven geographical differentiation of the C. ciliata bacterial community provides insights into the “insect–microbiome” interactive invasion mechanism that is present here.