Thrips pests have become an increasing concern in cotton fields in Xinjiang. Frankliniella intonsa is the primary thrips species during the flowering and boll stages, causing boll stiffening or cracking. However, limited studies have been conducted on controlling F. intonsa. In this study, using a leaf-tube residue method, we evaluated the susceptibility of F. intonsa field populations to three insecticides (spinetoram, imidacloprid, and acetamiprid) collected from different geographical sites across major cotton planting areas in Xinjiang. The results showed that F. intonsa populations exhibited very high susceptibility to spinetoram, ranging from 0.003 mg L⁻¹ in the Shihezi population to 0.036 mg L⁻¹ in the Korla population. The susceptibility of F. intonsa to imidacloprid and acetamiprid varied considerably among different field populations, with the relative resistance of 33.00 and 25.71, respectively. Reduced susceptibility to all three insecticides was detected in the Korla and Manasi populations, highlighting the importance of implementing effective resistance management and alternative control strategies. These findings provide valuable information for the appropriate control of F. intonsa in Xinjiang.

Fusarium head blight is one of the major diseases affecting wheat ears, and it is highly pathogenic and destructive. The pathogen, Fusarium culmorum, is a filamentous fungus capable of infecting crops, such as wheat, barley (Hordeum vulgare), and corn (Zea mays). The mycotoxins produced by this pathogen not only markedly reduce the nutritional value of grains but also pose a serious threat to public health. It has been shown that the antimicrobial substances in the secondary metabolites of Bacillus subtilis BS-Z15, mycosubtilin (Myco), and the crude extract of antimicrobial substances (AP), which contains the same content of Myco, can significantly inhibit the germination of conidia and mycelial growth of F. culmorum. It causes the spores to shrink and hyphae to break. The antimicrobial rate of A15 treatment reached roughly 77.77% after 4 days. Both AP and Myco reduced the disease index of wheat scab, with the control effect of AP reaching approximately 54.48% after 21 days of application. The control effect and inhibitory effect on pathogens of AP were superior to those of Myco at the same concentration. A transcriptome analysis indicated that the AP primarily regulates the proteasome pathway, DNA replication pathway, and peroxisome pathway in F. culmorum, while Myco primarily influences the proteasome pathway, fructose and mannose metabolism, and DNA replication pathway in this pathogen. Liquid chromatography-mass spectrometry was used to analyze the secondary metabolites of BS-Z15, and it was found that in addition to Myco, it also contains substances with antifungal activity or effects on plant growth, including 2-hydroxycinnamic acid, cinnamaldehyde, acrylamide, piperidine, myriocin, palmitic acid, L-histidine, and indole lactic acid. The secondary metabolites of BS-Z15 have demonstrated significant efficacy in the biological control of wheat scab by downregulating the expression of genes in pathways related to the conversion of compounds, energy metabolism, and cell growth of F. culmorum. The AP exhibits superior control and antimicrobial effects compared to Myco, which may be attributed to the synergistic interactions between Myco and other antimicrobial components found in the secondary metabolites of BS-Z15. This study provides a theoretical foundation for the further exploration of other antifungal components within the secondary metabolites of BS-Z15 and lays the groundwork to develop BS-Z15 as a biological control agent.

Symbiotic bacteria in insects are known to play crucial roles in detoxification metabolism and adaptation to host plant secondary metabolites. In the cotton-growing region of Xinjiang, China, the Ap. gossypii and the Ac. gossypii exhibit significant differences in sensitivity or resistance to pesticides. However, whether their detoxification-related symbiotic bacteria change under insecticide stress remains unclear. This study assessed the toxicity of nitenpyram to both aphid species and the effects of LC₂₀ treatment on their growth, development, and reproduction. Bacterial community dynamics across generations (G0–G2) were analyzed by 16S rRNA gene amplicon sequencing. The LC₂₀ of nitenpyram reduced the longevity and fecundity of the parent generation in both species. In Ap. gossypii, the intrinsic rate of increase (r_m), net reproductive rate (R₀), and finite rate of increase (λ) increased in the G1–G2 generations, whereas these parameters significantly decreased in Ac. gossypii. By the G3 generation, biological parameters in both species showed no significant differences compared to the control. Nitenpyram disrupted the stability of symbiotic bacterial communities in both aphids. In Ac. gossypii, Sphingomonas, a genus with detoxification potential, was consistently suppressed in G1–G2, while the abundance of the primary symbiont Buchnera initially decreased sharply and subsequently recovered. In contrast, the bacterial community in Ap. gossypii remained largely stable. These findings indicate that sublethal concentrations of nitenpyram exert distinct transgenerational effects on the two aphid species and disrupt the stability of their symbiotic bacterial communities.