Conservation biological control of codling moth, Cydia pomonella

Abstract: Ecological infrastructures in apple orchards may reduce pest infestation by improving conditions for natural enemies. The present study assessed the density of overwintering codling moth Cydia pomonella L. (Lepidoptera, Tortricidae), level of parasitism, infestation by entomopathogenic fungi and other mortality factors in five organic orchards with flower strips and five organic orchards without flower strips. In orchards with flower or grassy strips, predation on sentinel prey was assessed in different distances from the strips. No clear difference was found between infestation levels in organic orchards with and without flower strips. Within orchards with flower strips mortality of codling moth larvae collected near flower strips was higher than for larvae collected further away from strips. Likewise mortality of sentinel eggs was higher in trees near the flower strip than further way. Lack of difference between orchards with and without flower strips could be a result of high variability between orchards. Within orchards with flower strips, there was increased predation activity and increased mortality of codling moth larvae from near flower strips that could be predator induced.