Edovum puttleri (Hymenoptera: Eulophidae), an Exotic Egg Parasitoid of the Colorado Potato Beetle (Coleoptera: Chrysomelidae): Responses to Temperate Zone Conditions and Resistant Potato Plants

Between 18.3 and 29.4°C, preimaginal developmental rates of the exotic egg parasitoid Edovum puttleri were linearly related to temperature. Survival was very low at 15.6°, and there was no survival at 12.8°C. In the laboratory, development required 217 ± 6 degree-days above a lower threshold of t = 9.9°C; in three field tests during the summers of 1982 and 1983, emergence occurred within 1 to 3 days of the predicted dates. Development was only slightly affected by photoperiods between LD 16:8 and 10:14; no dormancy was observed in our laboratory or in field experiments. This strain of E. Puttleri, originally from Colombia, South America, appears to be poorly adapted to the climate of the northeastern United States. Furthermore, laboratory studies suggest that it is not especially welladapted to insect resistant Solanum plants bred for high densities of glandular pubescence. Our results indicate the need for further research with E. Puttleri in two areas: The development of methods of inundative releases, and searches for biotypes that develop and overwinter at low temperatures and that can tolerate Solanum species bearing glandular trichomes.