Exclusion cage studies of larval survival of P. pyrusana using differnt meshes of screen were conducted in 2 apple orchards in spring and summer of 2001. Results show that between 50 to 90% mortality is caused by small, presumably insectan predators and unknown mortality. Depending on the spatial position of the study area compared to riparian landscape elements, season, and pesticide use, virtually all or none of the larvae surviving predation were parasitized. The survival patterns in exclusion studies are compared to concurrent studies of the pattern of parasitism in 2 large orchard/landscape mosaics. The results support the proposition to modify habitats in or near orchards to harbor alternate lepidopteran hosts for key parasitoids, especial Colpoclypeus florus. A first attempt at these orchard/habitat modifications is shown to modestly increase parasitism near planted gardens that provide a source of alternate hosts.
Species 1: Lepidoptera Tortricidae Pandemis pyrusana (Pandemis leafroller)
Species 2: Hymenoptera Eulophidae Colpoclypeus florus
Keywords: Predation, parasitism
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA