Submitted to: Society for Invertebrate Pathology Annual Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2000
Publication Date: N/A
Interpretive Summary: NA
Technical Abstract: Tachinaephagous zealandicus is an encyrtid parasitoid of house flies and other muscoid Diptera inhabiting livestock and poultry manure. The parasitoids attack mature fly larvae as they seek pupation sites, depositing multiple eggs in the hemocoel of the larva. The host pupates and continues developing slowly while the parasitoid larvae develop within the body cavity. The host is killed near the end of the parasitoids' development, and the T. zealandicus immatures pupate within the mummified host remains. Development is completed in 22-25 days at 25 degrees C. A colony of T. zealandicus from Brazil recently was found to be 100% infected with a microsporidian pathogen resembling Nosema muscidifuracis, a pathogen of the pteromalid parasitoid Muscidifurax raptor. Transmission testing indicates that the pathogen is transmitted transovarially. Horizontal transmission occurs when larvae of uninfected and infected parasitoids occur within the same host. Infected females have reduced longevity and produce about half as many progeny as healthy females. Infection has no substantial effect on sex ratios or development time of the parasitoids. Heat shock was not effective for managing the disease because of the sensitivity of the host parasitoid to elevated temperatures. Per os administration of a 1.5% solution of rifampicin to adult T. zealanidus resulted in reduced rates of maternal transmission. This reduction was sufficient to allow the isolation of clean females and the establishment of an uninfected colony of the parasitoid.