title: Diapause, pupation sites and parasitism of the horn fly, Haematobia irritans, in south-eastern Brazil.
abstract: In order to verify the occurrence of diapause, preference for pupation sites and hymenopteran parasitism, the pupae of the horn fly, Haematobia irritans (Diptera: Muscidae), were collected from undisturbed cattle dung pats in pastures, and adults of the fly were sampled from cattle in São Paulo State, south-eastern Brazil, from April 1993 to July 1994. Diapause was verified in 7.7% of pupae sampled from pastures in June and July of 1993 and in 9.9% of those sampled in May, June and July of 1994 (overall rate of 9.1%). Approximately 8.3% of the pupae were parasitized by microhymenopterans, mostly Spalangia nigroaenea and S. cameroni (Hymenoptera: Pteromalidae). Horn fly pupae were found almost exclusively inside the pat or in the soil immediately beneath and adjacent to it, and very few were collected elsewhere. Pupa mortality was 54.4% and did not change significantly during the year, but mortality was greater among pupae collected in pastures when compared to those obtained from experimental pats, lacking natural enemies.
authors.affiliation: Department of Pathology, Federal University of Uberlândia, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Mendes
authors.forename: A X
authors.initials: AX
authors.lastname: Linhares
mesh_terms: D000818:Animals; D001938:Brazil; D002417:Cattle; D006927:Hymenoptera; D009117:Muscidae / Q000469:parasitology* / Q000502:physiology; D011679:Pupa / Q000469:parasitology