The utilization efficiency of conventional pesticides is relatively low in agricultural production, resulting in excessive application and environmental pollution. The efficient utilization of pesticides is crucial for promoting sustainable agriculture, and the development of nanopesticides presents a promising solution to the challenges associated with traditional pesticides. In order to explore an efficient application method for indendicarb (IDC), a star polymer nanocarrier (SPc) was employed to design and construct an efficient nanodelivery system for IDC. In this study, the morphology and physicochemical properties of the complex were determined, and its bioactivity and control efficacy were assessed using leaf-dipping and field spraying methods. The results show that IDC could be spontaneously incorporated into the hydrophobic core of SPc via hydrophobic association. This assembly disrupted the self-aggregated structure of IDC and significantly reduced its particle size to nanoscale. Furthermore, IDC emulsifiable concentrate (IDC EC) demonstrated improved adhesion to plant leaves with the aid of SPc, increasing retention from 8.083 to 10.418 mg/cm². The LC₅₀ (1d) of IDC EC against Plutella xylostella (Linnaeus) and Pieris rapae (Linnaeus) decreased by 6.784 and 1.931 times, respectively, with the addition of SPc. The inclusion of SPc increased the control effect of IDC EC by up to 8.28% (7d, 3000×) for P. xylostella and 12.53% (3d, 8000×) for P. rapae. This reveals that the IDC EC + SPc formulation exhibits superior insecticidal activity against these two highly destructive insect pests. This study successfully developed a novel nanodelivery system for the efficient application of IDC, which has the potential to reduce over-application and promote sustainable agricultural practices.

To investigate the population dynamics and correlation between wheat aphids and their natural enemies, we conducted a checkerboard sampling study in Yantai, Shandong province from 2019 to 2022. The main types of wheat aphids observed were S. miscanthi and Rhopalosiphum padi. S. miscanthi was found to occur on May, while R. padi appeared on June. The population dynamics of S. miscanthi followed a parabolic pattern, with peak numbers reached in mid-to-late May, followed by a decline. Similarly, the population of mummified aphids also exhibited a parabolic trend, and there was a linear correlation between the number of mummified aphids and S. miscanthi. However, mummified aphids appeared 4–10 days later than S. miscanthi. Furthermore, the occurrence trends of wheat aphids and their natural enemies generally aligned with each other, except in 2020 when the natural enemies emerged 10 days later than wheat aphids. This indicated a clear follow-up relationship between mummified aphids and S. miscanthi, as well as an evident following relationship between the natural enemies and wheat aphids. In conclusion, our study highlights the interplay of population dynamics among wheat aphids, mummified aphids, and their natural enemies in the Yantai region. These findings can contribute to a better understanding of ecological interactions in agricultural ecosystems and potentially aid in the development of integrated pest management strategies.

The purpose of this study is to discover and excavate more key factors and signaling pathways that regulate the formation intensity of biofilms and to fully reveal the possible models affecting biofilm formation. By using gene homologous recombination and bioinformatics technology, a MutL protein-directed deletion mutant strain was successfully constructed. The growth status of the mutant strain was observed, and it was confirmed that, except for the change in cell morphology, there were no significant differences in growth and reproduction between the mutant strain and the wild-type strain. By using the induced biofilm formation technique, the significant decrease in biofilm formation in the MutL mutant strain was successfully verified. The plate confrontation test confirmed that the inhibitory ability of the mutant strain against rice blast fungus was not significantly different from that of the WT strain. The colonization ability of the mutant strain on rice stems was tested, and it was confirmed that the colonization ability of the mutant strain was significantly lower than that of the WT strain. In terms of the prevention and control effect of rice blast disease, the mutant strain showed a significant decrease. By using transcriptomic big data, the gene and pathway expression differences between the mutant strain and the WT strain during biofilm formation were analyzed. The analysis revealed no significant correlation with the previously reported spo0A and tapA-sipW-tasA pathways. The key factor capB of the polyglutamic acid signaling pathway, which affects the formation of the biological model, was found to have a significant decrease in expression. A mechanical hypothesis was proposed: MutL may participate in regulating the formation intensity of Bacillus biofilms by regulating the formation of glutamic acid to polyglutamic acid.