Fei Zhao

BACKGROUND: The Chinese pear psyllid ( Cacopsylla chinensis ), a vector of the bacterial pathogen Erwinia amylovora , displays seasonal polyohenism, transitioning from a summer‐form to a winter‐form in response to temperature fluctuations. Although the winter‐form phenotypes, characterized by enhanced cuticular melanization and thickening, have been extensively documented, the underlying molecular regulatory network remains poorly understood. Given the pivotal biological functions of laccases in insect cuticular melanization and sclerotization, in this research, we systematically investigated the molecular characteristics of the laccase genes CcLac1 and CcLac2 , as well as their regulatory roles in driving this seasonal polyphenism. RESULTS: Our results showed that CcLac2 was predominantly expressed in the epidermis and markedly upregulated under low‐temperature conditions. Functional investigations using RNA interference (RNAi) further revealed that CcLac2 plays an essential role in promoting the transition from the summer‐ to winter‐form by orchestrating cuticular pigment deposition, cuticle thickening, and chitin deposition. In contrast, CcLac1 was not significantly involved in low‐temperature mediated morphological alterations. CONCLUSION: In summary, this study provides solid experimental evidence confirming that CcLac2 is critical for seasonal morph transition in C. chinensis , advancing our understanding of the molecular mechanisms underlying arthropod seasonal adaptation and identifying potential molecular targets for precision‐based management strategies for this economically important pest. © 2026 Society of Chemical Industry.

Climate change and insecticides negatively impact organism development and reproduction. Previous studies on climate change have focused on average temperature while ignoring diurnal temperature fluctuations. Therefore, this study investigates the interaction effects of the nymph experiencing temperature amplitudes (TAs) (+/−0, +/−6, +/−12 °C) at the same average temperature (22 °C) and two insecticides (beta-cypermethrin: negative temperature coefficient NT, imidacloprid: positive temperature coefficient PT) in the adult phenotypes and population parameter of S. avenae. The findings revealed that wide amplitude (+/−12 °C) significantly decreased fecundity, daily nymph reproduction, and the intrinsic rate of increase, while it significantly enhanced early fecundity. Medium amplitude (+/−6 °C) significantly lowered the intrinsic rate of increase. Notably, insecticides mitigated or even reversed the harmful impact of wide amplitude on adults. Under PT treatment, longevity was significantly higher than that under 22 °C. Under NT treatment, survival was noticeably greater than that under 22 °C. The interaction between insecticide and medium amplitude positively influenced adult phenotypes, with both PT and NT treatments resulting in higher survival, longevity, fecundity, and daily nymph production compared to 22 °C. These findings support the theory of climate-induced poison sensitivity and indicate that insecticide temperature coefficient is crucial in assessing insecticide safety risks under climate change scenarios.

Heatwaves are predicted to become more frequent under climate change. However, how different heatwave types and frequencies are linked to multigenerational ecological response remains unclear. Thus, using three heatwave types (34 °C/180 min, 36 °C/30 min, and 38 °C/10 min) and three frequencies (1, 3, and 5 days), we tested the effects of heat stress on the life history traits of Sitobion avenae. Both heatwave type and frequency altered aphid fitness in a generation-specific manner. In maternal generations, at a 1-day frequency, 34℃/180 min exhibited the greatest effects on reproduction and longevity. However, as frequency increased, differences across various heat stress treatments diminished. Conversely, in offspring, 34℃/180 min had minimal effects on demographic parameters. Offspring performance was poorest at the 3-day frequency, indicating that a longer frequency for the mother does not necessarily mean a greater effect on the offspring. Changes in aphid fitness due to heatwave type and frequency are driven by asymmetric effects of heatwaves on aphid life history. Furthermore, understanding how heat stresses affect the life history of aphids is important for predicting the impacts of climate change at the generational level because climate effects on natural populations cannot be predicted simply through changes in mean temperature.

Rhopalosiphum maidis Fitch, 1856 is widespread in tropical and temperate regions. R. maidis can spread viral diseases in maize and harm various important crops. In the present study, we report the first complete mitochondrial genome of R. maidis. The circular genome is found to be 17,021 bp in length, includes a standard set of 22 transfer RNAs, two ribosomal RNAs, 13 protein-coding genes, and two non-coding control regions. The base composition is 84.32% AT and 15.79% GC. The phylogenetic tree of the 17 Aphidini families constructed based on the nucleotide sequences of complete mitochondrial genomes strongly supports the conclusion that R. maidis is closely related to R. rufiabdominalis.

Introduction: Climate change not only directly affects the phenotype of organisms but also indirectly impacts their physiology, for example, by altering their susceptibility to insecticides. Changed diurnal temperature fluctuations are an important aspect of climate change; ignoring the impact of these fluctuations on the biological effects of various chemical insecticides can lead to inaccurate assessments of insecticide risk under the current and future climate change scenarios.Methods: In this study, we studied effects of different temperature amplitudes (± 0, ± 6, ± 12°C) at the same mean temperature (22°C) on the life history traits of a globally distributed pest (Sitobion avenae, wheat aphid), in response to low doses of two insecticides. The first, imidacloprid shows a positive temperature coefficient; the second, beta-cypermethrin has a negative temperature coefficient.Results: Compared with the results seen with the constant temperature (22°C), a wide temperature amplitude (± 12°C) amplified the negative effects of imidacloprid on the survival, longevity, and fecundity of S. avenae, but significantly increased the early fecundity of the wheat aphid. Beta-cypermethrin positively impacted the wheat aphid at all temperature amplitudes studied. Specifically, beta-cypermethrin significantly increased the survival, longevity, and fecundity of S. avenae under medium temperature amplitude (± 6°C). There were no significant differences in the survival, longevity, and the early fecundity of S. avenae when it was treated with beta-cypermethrin at the wide temperature amplitude (± 12°C). However, the negative effect of beta-cypermethrin on the intrinsic rate of increase of S. avenae decreased gradually with the increase in temperature amplitude.Discussion: In conclusion, the response of S. avenae to positive temperature coefficient insecticides was markedly affected by temperature amplitude, while negative temperature coefficient insecticides increased the environmental adaptability of S. avenae to various temperature amplitudes. Our results highlight the importance of the integrated consideration of diurnal temperature fluctuations and different temperature coefficient insecticide interactions in climate-change-linked insecticide risk assessment; these results emphasize the need for a more fine-scale approach within the context of climate change and poison sensitivity.

Background Tetanops sintenisi is a pest that mainly damages the root of quinoa (Chenopodium quinoa) and it is first discovered in China in 2018. Methods and Results Here, the complete mitochondrial genome (mitogenome) of T. sintenisi was sequenced and compared with the mitogenomes of other Diptera species. The results revealed that the mitogenome of T. sintenisi is 15,763 bp in length (GenBank accession number: MT795181) and is comprised of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA genes, and a non-coding A + T-rich region (959 bp). The highly conserved gene arrangement of the mitogenome of T. sintenisi was identical to that of other Diptera insects. Twelve PCGs contained the typical insect start codon ATN, while cox1 had CGA as the start codon. The genes cox2, nad4, and nad1 contained an incomplete termination codon T; nad3, nad5, and cob contained the complete termination codon TAG; and the remaining seven PCGs contained the termination codon TAA. All tRNA genes were predicted to fold into the typical cloverleaf secondary structure. Phylogenetic analysis of 48 species based on the mitogenome sequence revealed that T. sintenisi clustered with the Tephritidae family, indicating that T. sintenisi and Tephritidae have a close phylogenetic relationship. Conclusions The phylogenetic relationship of T. sintenisi based on the mitogenome is consistent with the traditional morphological taxonomy, according to which T. sintenisi belongs to the family Otitidae, which is closely related to the family Muscidae.

Temperature fluctuation is one of the most important factors in climate change, and research into its effects on organisms is increasing. Nonetheless, few studies have addressed its effects on insects and particularly on the parental generation. We therefore simulated temperature amplitudes (± 0, 4, 6, 8, 10°C) for a mean environmental temperature of 25°C and studied their immediate and maternal effects on a global pest, the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae), focusing on adult longevity and fecundity and egg development and survivorship in the next generation. Relative to constant temperature, moderate amplitudes (4 and 6°C) did not affect the adults, whereas 8 and 10°C amplitudes hindered adult longevity and fecundity, but significantly increased the proportional of early fecundity after each treatment. Temperature amplitude 10°C inhibited development of Day 2 and Day 3 laid eggs. These findings show that temperature amplitude affects both the maternal and offspring phenotype and indicate that the influence of temperature amplitude on diamondback moth population models requires further research.

Daily temperature amplitudes (DTAs) significantly affect the ecological and physiological traits of insects. Most studies in this field are based on laboratory experiments, while there is limited research on the effects of changes in DTA on insect phenotypic plasticity under natural conditions. Therefore, we studied the acclimation effects of DTA on the longevity, total fecundity, early fecundity, and the thermal tolerance of adult diamondback moths (Plutella xylostella L.) under naturally occurring environmental conditions. As DTAs increased, male longevity and total fecundity decreased, and early fecundity increased. An increase in DTA was significantly associated with the increased heat coma temperature (CT_max) of both males and females, but had no significant effect on their cold coma temperature (CT_min). Our findings highlight the effects of DTA on the acclimation response of P. xylostella and emphasize the importance of considering DTA in predicting models for assessing insect populations and the effects of climate change.

The first complete mitochondrial genome of Lixus subtilis Boheman is reported in this study. The circular genome is 15,223 bp long, including a standard set of 21 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), 13 protein-coding genes, and a non-coding control region. The trnI gene was not found in the L. subtilis mitogenome. All tRNAs had the typical cloverleaf structure, except for trnS1, which lacked the dihydrouridine arm. The phylogenetic tree of 13 Curculionidae species based on the concatenated nucleotide sequences of complete mitochondrial genomes strongly supported that L. subtilis is closely related to Curculioninae and Molytinae.