Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2000
Publication Date: 10/20/2001
Citation: JOHNSON, J.A., GRISSELL, E.E., GOKHMAN, V.E., VALERO, K.A. DESCRIPTION, BIOLOGY AND KARYOTYPE OF A NEW PSILOCHALCIS (HYMENOPTERA: CHALCIDIDAE) FROM INDIANMEAL MOTH PUPAE (LEPIDOPTERA: PYRALIDAE) ASSOCIATED WITH CULLED FIGS. PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON. 103(4) 777-787. Interpretive Summary: As part of a project to integrate natural enemies into non-chemical control programs for postharvest insect pests of dried fruits and nuts, a survey was made of the insects present at a culled fig warehouse in Fresno, California. Substandard figs, warehoused and sold for cattle feed, develop large pest populations, which in turn support various natural enemy populations. During the course of the survey, we discovered an undescribed species of Psilochalcis, belonging to the wasp family Chalcididae, parasitizing pupae of several stored product pyralid species. ARS researchers described the new species as Psilochalcis brevialata Grissell and Johnson and included observations on its biology and gene structure. This species is the first Psilochalcis associated with stored product pyralids. P. brevialata showed a haploid chromosome number of 6, the highest for the family Chalcididae. Female P. brevialata had relatively long reproductive lives (nearly 40 days), producing about 3-4 offspring each day for a total of about 130 progeny per female. Laboratory and field observations indicate that P. brevialata may be more heat tolerant than other pyralid parasites, and may therefore prove to be a useful component of a biologically based control program for postharvest dried fruits and nuts in the hot central valley of California.
Technical Abstract: Psilochalcis brevialata Grissell and Johnson, new species, is described and illustrated based on specimens from a laboratory culture reared on Plodia interpunctella (Hubner) pupae. This species, isolated from a culled fig warehouse in central California, is the first Psilochalcis associated with stored product pyralids. The karyotype of P. brevialata showed a haploid chromosome number (n) of 6, the highest n value for the family Chalcididae. Female P. brevialata had relatively long reproductive lives (39.3 days), producing an average of 3.3 progeny/day for a total of 128.7 progeny per female.