Maize stalk rot is a soilborne disease that poses a serious threat to maize production worldwide, with the most significant cause being fungal stalk rot. The development of a visual and rapid detection method for the maize stalk rot pathogen is significant for its prompt and accurate identification, enhancing agricultural production efficiency, and implementing timely preventive measures. These measures will help safeguard the maize yield and quality, ultimately reducing agricultural losses. In this study, we aimed to develop an efficient method to detect maize stalk rot pathogens. We focused on three pathogenic fungi commonly found in maize-producing regions worldwide: Fusarium verticillioides, F. proliferatum, and F. graminearum. Based on translation elongation factor 1-α, we developed a rapid detection technique using recombinase polymerase amplification–CRISPR/Cas12a, combined with test strips to develop an on-site rapid visual detection test for these pathogens. The method showed detection sensitivity for F. verticillioides, F. proliferatum, and F. graminearum within 20 min at concentrations of 7.8 pg/μl, 0.11 ng/μl, and 0.13 ng/μl, respectively. The sensitivity increased with increasing reaction time. Testing of field disease samples indicated that the method is effective in detecting nucleic acids obtained through crude extraction methods. In conclusion, we developed a visually rapid detection technology that does not rely on complex instruments and equipment for the on-site early detection of F. verticillioides, F. proliferatum, and F. graminearum in the field to implement effective control measures, ensuring stable and high maize yields.

Phthorimaea absoluta, an important pest of tomato crops, has reportedly developed high levels of resistance to the insecticide chlorantraniliprole, which has a unique mode of action and high efficacy. This study evaluated the sustained multigenerational effects of chlorantraniliprole on P. absoluta, focusing on resistance development, growth, development, reproductive capacity, population parameters, and nutritional indicators. After continuous selection with sublethal chlorantraniliprole for eight generations (CX-Sub₈), bioassays showed that CX-Sub₈ had 225.37-fold higher resistance than the susceptible strain. The age-stage, two-sex life table analysis revealed that the preadult development time and mean generation time were significantly prolonged, while population reproduction and pupal weight were reduced. Moreover, the relative fitness of CX-Sub₈ was 0.62, and changes in the life table parameters correlated with an increase in the serial number of selection cycles. The second-instar larvae of CX-Sub₈ presented lower triglyceride, glycerol, trehalose, free fatty acid, and protein contents than the unselected strain (CX-S₈). Transcriptome analysis identified 2517 differentially expressed genes, with most being enriched in nutrient metabolism-related pathways, such as amino acid biosynthesis and fatty acid degradation metabolism. These results indicate that multigenerational sublethal chlorantraniliprole treatment disrupts the nutritional metabolism, and inhibits the growth, development, and reproduction of P. absoluta.

The Colorado potato beetle, Leptinotarsa decemlineata, is a major insect pest of potatoes. Our previous studies have demonstrated that two cytochrome P450 monooxygenase (P450s) genes, CYP9Z140 and CYP9AY1, and a uridine diphosphate–glycosyltransferase (UGT) gene, UGT321AP1, play important roles in thiamethoxam resistance to L. decemlineata. However, the related upstream regulatory mechanism remains unclear. In this study, we first monitored the resistance of L. decemlineata field populations to thiamethoxam in Xinjiang to determine the resistance ratios. The predicted results demonstrated that four transcription factors (TFs), CncC/Maf, Abd-B, FoxO, and Ptx1, may bind to the core regions of three gene promoters. The qRT-PCR results revealed that the TFs were significantly upregulated by thiamethoxam and exhibited specific spatiotemporal expression patterns. Dual-luciferase reporter assays indicated that the CncC pathway could regulate the expression of three detoxification genes, whereas Abd-B and FoxO only regulate CYP9Z140 and UGT321AP1 expressions, respectively. Ptx1 could regulate the expression of both CYP9AY1 and UGT321AP1. Furthermore, knockdown of several TFs through RNA interference significantly reduced expression of the corresponding detoxification genes, consistent with the dual-luciferase reporter assay results, and increased the thiamethoxam susceptibility of test adults. These findings aid in gaining a deeper understanding of the transcriptional regulation mechanisms of insecticide resistance in insects.

Invasive alien species are generally highly fertile and adaptable and can pose a severe threat to the ecological security of invaded localities. Bemisia tabaci (Gennadius) is a rapidly evolving cryptic complex. Among them, Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) is the most invasive and widely distributed. To clarify the invasion source, population structure, and genetic differentiation drivers of whitefly populations in Xinjiang, China, we collected B. tabaci from 14 host crops in Xinjiang, China. A total of 453 sequenced cytochrome c oxidase subunit I(COI) fragments were analysed. We used common methods and parameters of genetic analysis, such as phylogenetic analysis, haplotype diversity, and nucleotide diversity, neutrality testing, and mismatch distribution chart analysis to determine the genetic structure and genetic differentiation and explore the origin of the invasion of B. tabaci populations in Xinjiang. The results have shown that global MED and MEAM1 populations are genetically differentiated, and MED has a significant geographical lineage structure at the Xinjiang and global spatial scales. This was the same for the MEAM1 population at the Xinjiang spatial scale. There have been multiple local expansions and founder effects in the MED populations. The MEAM1 population has retained a stable population size with a bottleneck effect. Based on the phylogenetic tree for MED and MEAM1, it has been demonstrated that there have been multiple points and pathways of invasion of B. tabaci and the sources in Xinjiang, China were complex. The sources of MED invasion of MED are likely to be Zhejiang, Hebei, or Shanxi. The source for MEAM1 is complex, and Zhejiang is one of the main invasion sources. This study has shown that host plant differences in open habitats, geographic isolation, and habitat differences were the driving factors for genetic differentiation of B. tabaci populations in Xinjiang, China