Azinphosmethyl resistance and flight phenology differences in codling moth adults in commercial and abandoned apple orchards in Pennsylvania

The codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae) is a serious pest of apples worldwide and causes significant damage to pome fruits. CM is well known for its ability to develop resistance to insecticides and the intensive applications of insecticides sprayed in fruit orchards have caused resistance development in CM populations across different apple growing regions of the world. Due to the frequent applications of insecticides, mainly organophosphates (such as azinphos-methyl, diazinon, parathion, phosmet, etc.) during the last 4-5 decades, CM has developed resistance to this chemical class, and it has again emerged as a serious threat to apples. In this study, adult topical bioassays were conducted in the laboratory to determine the susceptibility of the CM (male) adult populations collected from commercial and abandoned apple orchards to various concentrations of azinphosmethyl, a predominant insecticide used to control CM in apple orchards for several decades. In addition, in field studies, flight phenology of CM adults (in terms of captures in different types of lure baited traps) was compared between commercial and abandoned apple orchards in Pennsylvania. We found significant differences between resistance/susceptibility levels of CM adult populations collected from these two different types of orchard ecosystems. Similarly, we found significant differences in CM flight phenology between these two orchard ecosystems.