Pesticide impacts on pear psylla natural enemies

Pear psylla, Cacopsylla pyricola (Förster) (Homoptera: Psyllidae), is the key pest of pears in the Pacific Northwest. Control, traditionally, has been with pesticides, but chemical control programs often fail due to development of insecticide resistance and destruction of the complex of natural enemies found in pear orchards. There are currently several insecticides available for use in pears against pear psylla that may variably impact natural enemies. Natural enemies in pear orchards are key to mid-and late-season control of psylla populations, and conservation is key to successful integrated pest management programs. To transition traditional pear psylla control programs to more integrated approaches that conserve natural enemies, we endeavored to understand the impact of alternative chemistries on the complex of natural enemies found in Pacific Northwest pear orchards. The objective of this study was to compare natural enemies’ mortality, behavior, and sub-lethal impacts of exposure to several commonly used pear psylla insecticides.