Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/12/2001
Publication Date: 12/12/2001
Citation: Siegel, J.P., Lacey, L.A., Vossbrinck, C.R. 2001. Impact of a north american isolate of the microsporidium nosema carpocapsae on a laboratory population of the codling moth, cydia pomonella. Journal of Invertebrate Pathology. Volume(78):244-250. Interpretive Summary: Nosema carpocapsae is a microorganism that infects the codling moth, Cydia pomonella. This pathogen of the codling moth was first described from Europe, and has since been found in Eurasian and New Zealand populations of the codling moth. This paper reports the first find of N. carpocapsae in North America. In our laboratory, infection reduced larval and pupal survival but did not affect adult reproduction. These results differ from those reported in a previous paper that examined a New Zealand isolate of N. carpocapsae. The genetic material of the North American isolate was compared to the genetic material of Bulgarian and New Zealand isolates, and there was no difference. This information was used to establish the relationship of N. carpocapsae to other species in the same genus. We were able to eliminate this pathogen from a colony of infected moths by isolating the larvae to eliminate transfer of this microorganism combined with only using individuals that developed the fastest to continue the colony.
Technical Abstract: Nosema carpocapsae is a microsporidian pathogen of the codling moth, Cydia pomonella. We report the occurrence of this pathogen in a colony originating from collections made in the United States. This is the first record of N. carpocapsae infecting North American codling moths. This North American isolate of N. carpocapsae was indistinguishable from isolates received from New Zealand and Bulgaria, based on small subunit ribosomal RNA (rRNA) sequencing, but was more virulent than the previously described New Zealand isolate. In the laboratory, infected larvae and pupae had increased mortality compared to their uninfected counterparts and developmental time increased by one week. There was no effect on female fecundity. Within a cohort of eggs laid by infected females, neonates that emerged first were more likely to be uninfected. We established an uninfected colony by interrupting horizontal transmission and only utilizing the larvae that emerged from the first laid eggs.