Aggregation Pheromones and Adjuvants Reduce Pesticide Dosage against Dendrothrips minowai by Enhancing Behavioral Stimulation and Pesticide Deposition

Dendrothrips minowai Priesner, a major pierced-sucking pest in tea plantations, is mainly controlled by chemical insecticides that induce severe ecological issues. Previously, we identified the aggregation pheromones released by D. minowai nymphs, though their behavioral regulatory effects remain unclear. Here, we found that these aggregation pheromones stimulated adult thrips, enhancing their behavioral activities 1.6- to 5.4-fold. The mortality of D. minowai doubled when chlorfenapyr was coapplied with aggregation pheromones on leaves. Moreover, adding aggregation pheromones to a half-dose of chlorfenapyr achieved a field control efficacy equivalent to that of the full dose alone. We further demonstrated that 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TDD) significantly enhanced the chlorfenapyr deposition. Ultimately, the co-application of aggregation pheromones and TDD reduced chemical pesticide use by 70% and biopesticide use by 50%, while shortening the preharvest interval of tea. This novel synergist greatly mitigates the pest resistance and environmental risks.