Combining female removal with mating disruption for management of Cydia pomonella in apple

Field studies tested the use of lure-baited traps for female removal (FR) of codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) in apple, Malus domestica Borkhausen, treated with sex pheromone-based mating disruption (MD-FR). Four lures were evaluated, including the combination of (E,Z)-2,4-ethyl decadienoate (pear ester, PE), (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and 6-ethenyl-2,2,6-trimethyloxan-3-ol (pyranoid linalool oxide, LOX), these three components with (E,E)-8,10-dodecadien-1-ol (PH), and two lures loaded with PH/PE. All lures were used with a co-lure loaded with acetic acid (AA). Studies examined the importance of trap type and density on moth catches. Seventeen trials were conducted in 1-3 ha adjacent paired plots treated with or without 60 traps ha-1 in Washington State from 2018-2020. Paired plots were each treated with MD and a similar spray regime. The mating status of females in the MD-FR plots were compared with females collected from blocks not treated with MD. The PE/DMNT/LOX + AA lure caught significantly more females than any other lure. The most effective trap was a bucket trap with a green top and a clear bottom. Total or female moth catches per trap did not decline across trap densities from 37 to 99 ha-1. MD-FR trials showed that levels of fruit injury could be significantly reduced 50–75% across each moth flight. The proportion of mated females was 8 to 19% lower in blocks treated with MD-FR than not treated with MD. Further studies are needed to refine key operational factors associated with MD-FR considering the economics of organic and conventional apple production across key varieties.