Submitted to: The Canadian Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2007
Publication Date: 4/10/2008
Citation: Horton, D.R., Guedot, C.N., Landolt, P.J. 2008. Attraction of male summerform pear psylla to volatiles from female psylla: effects of female age, mating status, and presence of host plant. The Canadian Entomologist 140:184-191. Interpretive Summary: Pear psylla is a destructive pest in pears throughout North America and Western Europe, for which new management tools are needed. ARS scientists at the Yakima Agricultural Research laboratory showed that males of the summerform type are attracted to volatile odors from female-infested pear seedlings and from females in the absence of foliage; male response depended upon female age but not female mating status. Data reported in this study are only the second example for any species of psyllid suggesting that females emit a volatile sex attractant, and the results of these studies should lead to advances in identifying the attractant for eventual use in monitoring or pest control programs.
Technical Abstract: Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), is a pest of pears throughout North America and western Europe. Previous studies in our laboratory showed that males of the overwintering form (winterform morphotype) were attracted to volatiles from pear shoots infested with post-diapause females. The current study shows that males of the summer morphotype also are attracted to volatiles from female-infested host material. Older females (8-10 d in age) were significantly more attractive to males than younger (2-5 d in age) females. Both virgin and mated females attracted males. The previous studies with the winterform morphotype failed to determine the source of the attractants (i.e., the infested host material or the females). We show here that volatiles from female summerforms attracted males even in the absence of host plant material; both living and freshly killed females were attractive. Our results support the hypothesis that female C. pyricola emit a volatile sex attractant, and have helped to further define the life history conditions in female pear psylla that lead to male attraction.