This study was carried out in Embrapa-Centro de Pesquisa Agropecuária do Pantanal, Corumbá, MS, Brazil, from June/92 to May/94. Manure samples of Nelore breed were collected monthly to quantify if Haematobia irritans (L.) populations and parasitoids were present. During two years, 588 H. irritans pupae were collected and 10% of parasitism were observed. The parasitoids species (Hymenoptera) found were: Spalangia nigroaenea (Pteromalidae), S. endius (Pteromalidae), Rhoptromeris sp. (Eucoilidae) and Trichopria haematobiae (Diapriidae). S. nigroaenea was responsible for 91.5% parasitism in pupae of H. irritans, this species and the other parasitoids species have low selectivity regarding host choice.
