The use of insect-specific odorants to control the behavior of insects has always been a hot spot in research on “green” control strategies of insects. However, it is generally time-consuming and laborious to explore insect-specific odorants with traditional reverse chemical ecology methods. Here, an insect odorant receptor (OR) and ligand database website (iORandLigandDB) was developed for the specific exploration of insect-specific odorants by using deep learning algorithms. The website provides a range of specific odorants before molecular biology experiments as well as the properties of ORs in closely related insects. At present, the existing three-dimensional structures of ORs in insects and the docking data with related odorants can be retrieved from the database and further analyzed.

Odorant binding proteins (OBPs) play a key role in the olfactory recognition of insects, whose functions have been extensively studied in adult insects but rarely in larvae. In this study, one OBP (SlitOBP11) with high expression in larval antenna but low expression in adult antenna of Spodoptera litura was screened by RNA-seq and verified by quantitative real-time PCR. Furthermore, the function of SlitOBP11 was explored by analysis of the expression patterns and prokaryotic expression of proteins as well as assays of competitive binding. Competitive binding assay demonstrated that SlitOBP11 had high binding affinity to all four female sex pheromone components, but exhibited almost no binding affinity to plant volatiles except for a low affinity to Phenylacetaldehyde and Phenethyl acetate. Homology modeling and molecular docking implied that the shape of these four sex pheromones were linear, which were appropriate for the binding channel of SlitOBP11 and the amino acid residue Asn99 of SlitOBP11 might play an important role in binding. Taken together, our results indicate that SlitOBP11 may be involved in the perception of female sex pheromones by S. litura larvae, and OBPs in the larvae of S. litura play an important role in the olfactory perception process.

Thiacloprid is a new chlorinated nicotinoid insecticide against stinging-oral pests, such as aphids. It is less toxic to bees, however, more toxic to earthworms. In this study, a pH- and amylase-responsive MOF (ZIF-8) was constructed for site-specific delivery of thiacloprid to control pea aphids and more safety for earthworms. The thiacloprid from α-cyclodextrin@Thiacloprid@ZIF-8 (α-CD@T@ZIF-8) could be released quickly in pea aphids, which was ascribed to disintegration of ZIF-8 in low pH values of pea aphids intestine and degradation of α-CD under the action of α-amylase. The release results showed a significant pH dependence of α-CD@T@ZIF-8, with around 65% release amount at pH=7 and 95% release amount at pH=5 for 7d. The results of pot experiment and biosafety showed that for α-CD@T@ZIF-8, 88% pea aphids could be killed compared with 32% ones for commercially available formulation on the 7th day after application, meanwhile it was more safety for pea and lower acute toxicity and enrichment for the earthworms. α-CD@T@ZIF-8 could be used for intelligently controlled release of other insecticide against aphids.

Berberine (Ber) is easy to synthesize and has a variety of biological and pharmacological activities. At present, the studies on berberine are mostly focused on antibacterial activity, and its herbicidal activity are rarely reported. In addition, there are few preparations of berberine, which are not enough to solve the shortcomings of low solubility and biological activity and difficult storage of berberine. Here, berberine was combined with carbon dots to get carbon dots-berberine (CDs-Ber) nano formulation. The fluorescence quenching results showed that the CDs-Ber nano drug delivery system was successfully constructed, and the fluorescence quenching mechanism of the two was static quenching. Bioassay results showed that CDs had no adverse effects on the growth of Echinochloa crusgalli and Amaranthus retroflexus , and had high biocompatibility. Berberine and CDs-Ber mainly affected the roots growth of E. crusgalli and A. retroflexus , and could enhance the growth inhibition effect on weeds to some extent. The results of protective enzyme system showed that both berberine and CDs-Ber could increase the activities of SOD, POD and CAT in E. crusgalli , and CDs-Ber had stronger stress effect on E. crusgalli than berberine. The determination of the number of bacterial communities in the soil after berberine and CDs-Ber treatments showed that there was no significant difference in the effects of the two, indicating that CDs-Ber would not have more negative impacts on the environment. CDs-Ber nano formulation improved the biological activity of berberine and enhanced the herbicidal effect, and was safe to the soil environment.