Attraction of male pear psylla, Cacopsylla pyricola, to female‐infested pear shoots

Abstract

AbstractPost‐diapause winterform pear psylla, Cacopsylla pyricola (Förster) (Homoptera: Psyllidae), exhibit a highly clumped distribution in late winter in pear orchards. The behaviors leading to clumped distributions in this species are unknown, but could include aggregation for mating activities. Choice tests and assays with an olfactometer were done to test whether male psylla of the overwintering morphotype are attracted to pear shoots infested by post‐diapause females and to shoots previously occupied by females. Paired choice tests in small arenas showed that males accumulated on pear shoots currently occupied or previously occupied by females if those shoots were paired with uninfested shoots or shoots previously occupied only by males. Assays with an olfactometer showed that males were attracted to volatile odors from female‐infested or previously infested shoots. The exact source of the attractants (i.e., the female psylla, the pear shoot, or a combination of these sources) remains to be determined.