Enhancing resistance management and performance of biorational insecticides with novel delivery systems in tree fruit IPM

Abstract

Twentieth century delivery systems co-evolved with insecticide discovery to meet the demands of pest management in an era of increasingly mechanized agriculture production. The attributes of ground air-assisted sprayers met the practical demands of farmers to deliver broad spectrum pesticides into large fields of crops in an economical and timely basis. In an age of cheap contact poisons and limited understanding of environmental risks, the logical and optimal placement of insecticides was on the foliar canopy of crops, lending to maximum contact toxicity to the target pests. The twenty-first century has witnessed the development of an array of biorational insecticide chemistries, with performance attributes distinct from those introduced in the twentieth century. None-the-less, farmers have continued to rely upon twentieth century delivery systems to apply both new and old materials, with little consideration of what changes might improve their performance. Trunk injection represents an alternative delivery system for biorational insecticides of trees, including tree fruit crops, which has the potential of maximizing the ingestive exposure of the compound to the target pest. Residue profile analysis of trunk injected insecticides shows that vascular delivery is predominantly to foliage, with fruit residues below USEPA maximum residue limits. Field and laboratory studies demonstrate seasonal effectiveness of trunk injected insecticides against key apple insect pests, suggesting that this is a promising delivering system for tree fruit IPM and resistance management.