Release of parasitoid wasps (Hymenoptera: Chalcididae and Pteromalidae) for control of house flies (Diptera: Muscidae) in poultry farms

A survey on the parasitoids attacking Musca domestica at four poultry houses at Namakkal indicated the prevalence of Spalangia endius, Dirhinus himalayanus and Pachycrepoideus vindemiae. Spalangia endius was the most abundant parasitoid (79.8%) followed by D. himalayanus (18.81%) and P. vindemiae (1.3%). The overall rate of parasitism of naturally occurring pupae was greater in narrow caged layer houses (21.78%) than in high rise poultry houses (17.5%). Weekly releases of Spalangia endius and Dirhinus himalayanus as a single species and combined release were conducted in four experimental poultry houses to evaluate the overall effect on house fly pupal parasitism and suppression of adult house fly densities. The overall parasitism of house fly puparia was greater in released houses (29.1%, 34.3% & 33.1%) than those from the non released control houses (13.7 and 15.6). Overall parasitism by S. endius and D.himalayanus was greater in field puparia (39.4%, 44.2% and 44.9%) than sentinel puparia (18.8%, 24.4% and 21.3%) in all the released houses. When the parasitoids were released together in equal numbers, emergence from house fly puparia was greater for S. endius (21.9%) than for D. himalayanus (11.3%). Maximum parasitism of naturally occurring pupae and sentinel pupae was recorded in the third week following release. Kruskal Wallis one way analysis of variance showed lowered house fly density in released houses as compared to non release houses. The mean number of fly specks per spot card between release and non release houses differed significantly (P<0.01). Mass release of laboratory reared S. endius and D. himalayanus simultaneously in adequate numbers at weekly intervals during the fly season may be an effective biological control measure for suppression of house fly population in small poultry farms.