Search Results (71)

Insect populations are increasingly exposed to concurrent climate warming and agrochemical contamination, yet how these stressors interact to influence reproductive performance remains poorly understood. Because fertility can constrain population growth before survival declines, understanding how environmental stress affects reproduction is essential for predicting demographic responses. Here, we investigated how elevated temperatures and sublethal imidacloprid exposure during development and early-life interact with the insecticide resistance locus Cyp6g1 to influence male reproductive performance in Drosophila melanogaster. Males were reared from embryo to adulthood under factorial combinations of temperature and insecticide exposure, and mating behaviour and fertilisation success were subsequently quantified under benign assay conditions. Early-life heat reduced fertilisation success in a genotype-dependent manner, with a pronounced collapse observed in insecticide-susceptible males. Sublethal insecticide exposure modified this thermal response, restoring fertilisation success in susceptible males and producing non-additive interactions between thermal and agrochemical stress. In contrast, although mating frequency varied across treatments, it did not show the pronounced decline observed in fertilisation success, indicating that behavioural engagement does not necessarily predict functional reproductive output. These results suggest that environmental stress experienced during early-life can reshape reproductive performance, potentially through genotype-dependent shifts in physiological investment. Considering developmental stress history and genetic variation will therefore be important for predicting insect population responses to climate warming and environmental contamination. Full article

Genetically modified (GM) plants have been commercially grown for 30 years, and their acceptance depends on a thorough risk assessment. Environmental Risk Assessment (ERA) evaluates potential impacts of releasing GM plants into the environment, whether through cultivation or import for food, feed, and processing. A key component is assessing potential gene flow to crop wild relatives or non-GM crops. For gene flow to significantly affect the environment, transferred genes must provide a selective advantage. Since most GM plants are engineered for herbicide tolerance, insect resistance, or stacked traits, evaluating such advantages is relatively straightforward. New genomic techniques (NGTs) can generate plants with a wider range of traits, including tolerance to biotic and abiotic stress. Although still considered GM in the EU, their genomic changes can complicate detection, identification, and ERA, especially when such traits may offer advantages under stress conditions. This scoping review focuses on gene flow in two crops: oilseed rape (canola) (Brassica napus L.) and potato (Solanum tuberosum L.). In canola, transgene movement can increase weediness, fitness, herbicide resistance, or genetic diversity in feral or related populations. Gene flow in potato is less studied, with concerns centered on contamination risks in the Andean diversity center. Limited data exist for NGT plants, though many are expected to resemble conventionally bred varieties, suggesting comparable environmental impacts. Full article

The artificially modified Bacillus thuringiensis (Bt) protein can target lepidopteran pests, and planting genetically modified crops with insect-resistant traits is environmentally friendly. However, it is still uncertain whether the exogenous insect-resistant proteins in genetically modified crops will affect the soil rhizosphere microorganisms. This study utilized 16S rDNA sequencing technology to analyze the rhizosphere soil of insect-resistant genetically modified corn LD05 and its control variety Zheng58 at five developmental stages: before sowing, seedling stage, jointing stage, silk emergence stage, and maturity stage. Each sample was taken with six biological replicates, resulting in a total of 60 sequencing samples, with an average of 4368 OTUs obtained per sample. Both alpha and beta analyses showed that LD05 and Zheng58 did not have a significant impact on the soil rhizosphere microbial community. The developmental stage rather than the variety was the main factor causing differences in the bacterial community. Overall, there was no significant difference in the bacterial diversity between the insect-resistant genetically modified corn LD05 and its control variety Zheng58. The results provide useful information for understanding the impact of genetically modified crops on soil microbial communities and also provide a theoretical basis for the safety evaluation of LD05. Full article

Mosquito-borne diseases are an emerging public health challenge in Europe, driven by the spread of invasive mosquito species capable of sustaining outbreaks of tropical arboviral diseases. Rising temperatures, shifting precipitation patterns, human-driven habitat changes, and prolonged transmission seasons have increased the risk of dengue, chikungunya, and West Nile virus outbreaks, among other vector-borne diseases. Effective control requires a multifaceted approach, combining traditional and novel methods with advanced surveillance technologies and community involvement. However, growing insecticide resistance and concerns about insecticide use highlight the need for more prudent management of current tools and the development of innovative alternatives. Genetic control strategies, including the Sterile Insect Technique (SIT), Wolbachia-based approaches, and genetically modified (GM) mosquitoes, offer promising solutions but still face scientific, regulatory, and societal challenges. This review explores the current landscape of mosquito-borne disease control in Mediterranean Europe, emphasizing key challenges and emerging solutions. An integrated approach that strengthens surveillance, promotes sustainable control methods, and incorporates novel biotechnological tools supported by smart technologies will be essential to reduce the future burden of mosquito-borne diseases in the region. Full article

The global population growth has driven the widespread adoption of genetically modified crops, with Bt maize, due to its insect resistance, becoming the second most widely planted GM crop. However, studies on the effects of continuous Bt maize cultivation on soil ecosystems are limited, and there is an urgent need to assess its ecological safety at the regional scale. To evaluate the potential effects of continuous cultivation of transgenic Bt maize on the soil ecosystem, a five-season continuous planting experiment was conducted using two Bt maize varieties (5422Bt1 and 5422CBCL) and their near-isogenic conventional maize (5422). After five consecutive planting seasons, bulk soil and rhizosphere soil were collected. The main nutrient contents of the bulk soil were measured, and high-throughput sequencing was employed to analyze microbial diversity and community composition in both soil types. The results showed that, compared with the near-isogenic conventional maize 5422, continuous planting of Bt maize varieties 5422Bt1 and 5422CBCL did not affect the contents of organic matter, total nitrogen, total phosphorus, total potassium, alkaline hydrolyzable nitrogen, available phosphorus, or available potassium in bulk soil. Regarding the microbial communities in bulk soil, there were no significant differences in the α-diversity indices of bacteria and fungi after five consecutive seasons of Bt maize cultivation, compared with soils planted with the near-isogenic conventional maize 5422. Proteobacteria and Ascomycota were the dominant phyla of bacteria and fungi, respectively. Principal coordinate analysis (PCoA) and redundancy analysis (RDA) revealed that the structure of microbial communities in bulk soil was primarily influenced by factors such as OM, TP, TN and AN, whereas the Bt maize varieties had no significant effect on the overall community structure. Regarding the rhizosphere soil microbial communities, compared with the near-isogenic conventional maize 5422, the evenness of the bacterial community in the rhizosphere soil of Bt maize decreased, leading to a reduction in overall diversity, whereas species richness showed no significant change. This change in diversity patterns further contributed to the restructuring of the rhizosphere soil microbial community. In contrast, the fungal community showed no significant differences among treatments, and its community structure remained relatively stable. Proteobacteria and Ascomycota were the dominant phyla of bacteria and fungi, respectively. Principal coordinate analysis (PCoA) indicated that continuous cultivation of Bt maize for five seasons had no significant effect on the structure of either bacterial or fungal communities in the rhizosphere soil. In summary, continuous cultivation of Bt maize did not lead to significant changes in soil nutrient contents or microbial community structures, providing a data foundation and theoretical basis for the scientific evaluation of the environmental safety of transgenic maize in agricultural ecosystems. Full article

The commercialization of genetically modified (GM) maize and soybean is advancing, with strip intercropping emerging as a promising model to enhance crop yields and resource efficiency. However, the impact of this system on target pests remains unclear. To address this, we evaluated eight different planting patterns (four different monocultures and four different strip intercropping integrations) of insect-resistant GM maize (‘RF88’) and soybean (CAL16) events and their non-transgenic parental lines (Xianyu 335 maize and Tianlong No. 1 soybean) in the Huang-Huai-Hai planting area from 2023 to 2025. Our results identified Helicoverpa armigera and Spodoptera exigua as the dominant pests on maize and soybean, respectively. We found that the GM trait significantly reduced the population density and plant damage caused by these pests. Strip intercropping also provided significant suppression across both crop lines. Furthermore, the integration of strip intercropping and the GM trait resulted in the most effective pest control. This study provides valuable insights for the top-level design and industrial layout of GM crop commercialization and contributes to promoting its safe application and sustainable pest management. Full article

Background: Trait convergence or parallelism is widely seen across the animal and plant kingdoms. For example, the evolution of eyes in cephalopods and vertebrate lineages, wings in bats and insects, or shark and dolphin body shapes are examples of convergent evolution. Such traits develop as a function of environmental pressures or opportunities that lead to similar outcomes despite the independent origins of underlying tissues, cells, and gene transcriptional patterns. Our current understanding of the molecular processes underlying these phenomena is gene-centric and focuses on how convergence involves the recruitment of novel genes, the recombination of gene products, and the duplication and divergence of genetic substrates. Scope: Despite the independent origins of a given trait, these model organisms still possess some form of epigenetic processes conserved in eukaryotes that mediate gene-by-environment interactions. These traits evolve under similar environmental pressures, so attention should be given to plastic molecular processes that shape gene function along these evolutionary paths. Key Mechanisms: Here, we propose that epigenetic processes such as histone-modifying machinery are essential in mediating the dialog between environment and gene function, leading to trait convergence across disparate lineages. We propose that epigenetic modifications not only mediate gene-by-environment interactions but also bias the distribution of de novo mutations and recombination, thereby channeling evolutionary trajectories toward convergence. An inclusive view of the epigenetic landscape may provide a parsimonious understanding of trait evolution. Full article

RNA interference (RNAi) represents a promising pest control strategy, applicable to both insect-resistant genetically modified (IRGM) crops and sprayable RNAi insecticides. These products can achieve sequence-specific gene silencing and require rigorous environmental risk assessment (ERA) prior to approval. However, current environmental safety assessments of RNAi products and other RNAi experiments frequently use double-stranded EGFP (dsEGFP) as a negative control, while suitable RNAi-based positive controls are lacking. Sometimes conventional chemical toxins (e.g., chlorpyrifos) or protein inhibitors (e.g., trypsin inhibitors) are used as substitutes, but their distinct mechanisms, persistence, and metabolism make them inappropriate for RNAi-specific evaluations. In this study, we evaluated the suitability of RNAi-based positive controls for assessing non-target effects on Harmonia axyridis, a widely distributed predatory beetle used as a bioindicator in biosafety assessments. Under laboratory conditions, we tested one microRNA (miR-92a) and two double-stranded RNAs (dsHaSnf7 and dsHaDiap1) for their effects on H. axyridis. Injection of miR-92a showed no significant difference in mortality compared to controls, whereas dsHaSnf7 and dsHaDiap1 significantly reduced survival rates and target gene expression, as confirmed by qPCR. These findings suggest that HaSnf7 and HaDiap1 are suitable candidate genes for establishing RNAi-specific positive controls in environmental risk assessments of RNAi-based products. Full article

Although traditional genetically modified (GM) cotton has reduced lepidopteran pests, secondary pests such as Adelphocoris suturalis Jakovlev (Hemiptera: Miridae) have become increasingly problematic. RNA interference (RNAi)-based insect-resistant plants offer a promising alternative, but their potential ecological risks, particularly within the plant–pest–natural enemy framework, require comprehensive evaluation. As a key natural enemy in cotton agroecosystems, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) plays a vital role in regulating pest populations and thus serves as an important non-target insect for environmental risk assessment. In this study, dsAsFAR transgenic cotton and the non-target insect H. axyridis were used to evaluate potential ecological risks. Based on the sequences of the HaFAR, AsFAR, and GFP genes, dsAsFAR, dsHaFAR, and dsGFP were synthesized in vitro and incorporated into artificial diets fed to H. axyridis, along with a ddH₂O control group. No significant differences were observed among the treatments across various developmental stages. Furthermore, H. axyridis was fed aphids that had been reared on either transgenic or non-transgenic cotton plants cultivated in a greenhouse. The findings indicated no significant differences in the growth, development, predatory ability, or fecundity of H. axyridis. These results suggest that transgenic dsAsFAR cotton targeting A. suturalis poses no detectable adverse effects on H. axyridis, supporting the environmental safety of RNAi crops within a plant–pest–natural enemy ecological interaction framework. Moreover, the dsAsFAR expressed in transgenic cotton was not effectively transferred through the food chain to affect homologous gene expression in H. axyridis. Full article

With the increasing severity of forest pest problems, breeding insect-resistant varieties has become a crucial task for the sustainable development of forestry. The highly insect-resistant triploid Populus line Pb29, genetically modified with BtCry1Ac, served as the maternal parent in controlled hybridization with three paternal Populus cultivars. Hybrid progenies were obtained through embryo rescue and tissue culture. Results showed that 4 °C storage was favorable for pollen preservation, with 84K poplar exhibiting superior pollen viability and embryo germination rates. All progenies displayed significantly lower seedling height and ground diameter growth than the maternal parent (p < 0.05), with some showing leaf shape and branching variations. Among the three crosses, the 84K-sired progeny exhibited the best growth performance but the highest variability. PCR analysis confirmed stable inheritance of the BtCry1Ac and Kan genes from Pb29, showing tight linkage. Progenies carrying BtCry1Ac exhibited detectable gene transcription and toxic protein accumulation, though expression levels varied due to copy number, insertion sites, and potential co-suppression effects. Ploidy analysis suggested all hybrids were aneuploid, with lower survival rates than the maternal parent. Insect-feeding assays confirmed high resistance in all BtCry1Ac-inheriting progenies, with an average larval mortality rate of 97.03%. Mortality rates and death indices significantly correlated with transcript abundance and toxin protein levels. These results demonstrate that BtCry1Ac insect resistance is stably inherited through hybridization. Transgene expression appears co-modulated by copy number, insertion sites, and ploidy status. Simultaneously, it was found that the aneuploid progeny derived from triploid hybridization exhibited growth disadvantages. This provides an important basis for subsequent poplar improvement breeding. Full article

While genetically modified crops bring significant economic benefits, the environmental safety issues they may pose have also received increasing attention. To study the impact of planting genetically modified insect-resistant crops on soil ecosystems, this research employed methods such as 16S rDNA amplicon full-length sequencing, using transgenic Cry1Ah insect-resistant corn HGK60 and its conventional counterpart Zheng 58 as subjects for a three-year continuous survey to analyze the effects of planting transgenic Cry1Ah insect-resistant corn HGK60 on the rhizosphere bacterial community. The following results were obtained. (1) A total of 216 corn rhizosphere soil samples were annotated to 51 phyla, 119 orders, 221 families, and 549 genera. (2) Overall, there was no significant difference in the composition of the rhizosphere bacterial community between HGK60 and Zheng 58 at the phylum, class, order, or family levels (p > 0.05), and the planting of HGK60 did not significantly affect the relative abundance of rhizosphere probiotics (p > 0.05). Some differences appeared only briefly and were not reproducible. (3) Alpha and beta diversity analyses showed that overall, the planting of HGK60 had no significant impact on the structure of the rhizosphere bacterial community (p > 0.05). (4) Significant changes in the rhizosphere bacterial community were observed across different growth stages of corn. It can be concluded that the planting of HGK60 has no significant impact on the rhizosphere bacteria. This study provides valuable data support for the environmental safety assessment of genetically modified crops. Full article

The fall armyworm (Spodoptera frugiperda (J.E. Smith)), which invaded China in 2018, has caused severe corn yield losses and increased pesticide application frequency. Bacillus thuringiensis (Bt)-based genetically modified corn represents an environmentally friendly and effective strategy for managing S. frugiperda. The transgenic corn LD05 harbors the m2cryAb-vip3A insect-resistant fusion gene, which has demonstrated potent inhibitory effects against fall armyworm and is currently in the phase of applying for safety certification. Here, we evaluated the inhibitory efficacy of LD05 against S. frugiperda through laboratory and field experiments during 2022–2024. The LC₅₀ and LC₉₅ of M2CryAb-VIP3A against fall armyworm were 0.024 μg/cm² and 0.508 μg/cm², respectively; and the GLC₅₀ and GLC₉₅ were 0.142 μg cm⁻² and 0.556 μg cm⁻², respectively. M2CryAb-VIP3A expression of LD05 varied significantly across tissues, and remained stable between generations. Bioassays revealed significant tissue-specific differences in fall armyworm larval mortality for LD05 corn tissues, ranked as V5-stage leaves > R3-stage kernels > R1-stage silks. Field trials demonstrated that LD05 corn significantly reduced fall armyworm larval populations, leaf damage incidence, and plant damage incidence compared to non-Bt control Zheng58. Agronomic trait analysis showed no significant differences between LD05 and Zheng58. These results indicate that LD05 has a significant inhibitory effect on fall armyworm, which is an effective strategy for the comprehensive management of fall armyworm in China. Full article

In recent years, agricultural crops have increasingly been attacked by more destructive insect pests, forcing modern farming to depend mainly on chemical insecticides. Although valuable, their widespread and intensive misuse has raised serious concerns about environmental and public health impacts. RNAi has been proposed as a safer alternative due to its high specificity, adaptability, and low ecological footprint. So far, dsRNA has proven effective in controlling various pest species, either through topical application or via genetically modified plants. Despite advances, large-scale implementation of RNAi remains challenging due to technical and biological hurdles that contribute to inconsistent performance. Key aspects such as dsRNA design, delivery techniques, and cellular uptake mechanisms still require refinement. Additionally, ensuring environmental stability, addressing biosafety concerns, and developing cost-effective production methods are essential for its practical application. In this review, we explore recent advances in the design and implementation of dsRNA, as well as the strategies that could support the successful integration of RNAi technology into pest management programs. Full article

Drosophila suzukii is a successful invasive insect species responsible for agricultural losses. The key to its prowess is the ability to swiftly adapt to new environments through various genetic mechanisms, including fast accommodation of mutations and gene expression fine-tuning. Piezo and nanchung (nan) genes are linked to circadian clock-related behaviors and, therefore, are expected to readily respond to stress stimuli. Herein, we compared the DNA sequences of Piezo, nan, and αTubulin at 67C, a highly conserved housekeeping gene, in ICDPP-ams-1, a Romanian local population of D. suzukii, and two well-annotated reference populations from the United States of America and Japan. Our results imply that short-term evolutionary accumulated single nucleotide and indel variants are overrepresented within introns, a propensity evaluated through the mutation accumulation tendency (MAT) original parameter. Piezo and nan gene expression under photoperiodicity changes challenges were assessed in a series of experiments on three groups of individuals from ICDPP-ams-1. We found that both genes are upregulated in females if their customary circadian rhythm is affected, a trend seemingly reverting if, after an initial perturbation, the circadian clock is reset to its initial timing. In conclusion, we found that both highly conserved and adaptability-related genes are rapidly evolving and that Piezo and nan have a fast functional reaction to circadian clock changes by modifying their gene expression profiles. Full article

Background: Genetic control tools, such as the sterile insect technique (SIT) and genetically modified mosquitoes (GMMs), require releasing males comparable to their wild counterparts. Ensuring that released males do not exhibit higher insecticide resistance is critical. This study assessed the phenotypic characteristics and insecticide susceptibility of key dengue and malaria vector species. Methods: Phenotypic resistance to deltamethrin (0.05%) was tested in two-to-five-day-old male and female Aedes aegypti (Linnaeus, 1762) (Borabora and Bobo strains) and Anopheles coluzzii (Coetzee & Wilkerson, 2013) (Vallee du Kou strain) using WHO susceptibility guidelines. Wing measurements of live and dead mosquitoes were used to assess body size. Results: Mortality rates were similar between male and female Ae. aegypti (Bobo strain) and An. coluzzii, while Ae. aegypti Borabora was fully susceptible in both sexes. Females were consistently larger than males, with significantly larger live females than dead ones in the Ae. aegypti Bobo strain. Conclusion: This study highlights sex-specific differences in body size and insecticide susceptibility. Integrating these analyses into vector management programs is essential for the success and sustainability of SIT- and GMM-based interventions targeting malaria and dengue vectors. Implications for integrating genetic control strategies are discussed. Full article