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.

Sazonalidade de Haematobia irritans no Brasil Central

“…Nesse período adverso ao desenvolvimento do inseto, segundo Mendes & Linhares (1999), ocorre diapausa em parte das pupas produzidas. Estes autores, no Estado de São Paulo, verificaram 7,7% de diapausa em pupas durante junho e julho de 1993 e 9,9% entre maio e julho de 1994.…”

“…Este inseto se dispersou em todo território brasileiro, (Mendes & Linhares 1999). O dano que lhe é atribuído com respeito à pecuária no Brasil foi estimado em US$ 150 milhões anuais (Grisi et al 2002).…”

Host Ranges of Six Solitary Filth Fly Parasitoids (Hymenoptera: Pteromalidae, Chalcididae) from Florida, Eurasia, Morocco, and Brazil

“…Most of the available literature on muscoid ßy parasitoids has involved trials with house ßies (Musca domestica L.) and stable ßies (Stomoxys calcitrans L.). By comparison, information on parasitism of other species such as the horn ßy (Hematobia irritans L.) is limited and mostly deals with Þeld surveys of ßies in various locations (McKenzie and Richerson 1993, Mendes and Linhares 1999, Sereno 2000, Marchiori et al 2000, 2002.…”

Effect of diflubenzuron on immature stages of Haematobia irritans (L.) (Diptera: Muscidae) in Uberlândia, State of Minas Gerais, Brazil

“…A moistened filter paper was placed in the cage as an egg laying substratum. A solution of water and sugar ad libitum was offered to the flies that were kept in darkness at a high population density (Mendes & Linhares 1999). The obtained eggs were removed from the filter paper every 3 h with the aid of a fine brush (Tigre® n. 0) and transferred to flasks containing breeding media.…”