Biology and Control of Cattle Grubs

PERSPECTIVES AND OVERVIEW Two species of cattle grubs (Diptera: Oestridae) affect cattle in the Northern Hemisphere: Hypoderma iineatum, the common cattle grub or lesser cattle warble fly, and Hypoderma bovis, the northern cattle grub or larger cattle warble fly. The word warble is Anglo-Saxon for boil. Adults of the cattle grub are commonly known as heel flies, warble flies, bomb flies, or gad flies. This parasite has been observed and recorded for centuries (159), and Bracy Clark (50) cited and discussed references from Biblical times to Shakespeare. Scientific observations on the biology were first recorded in the 1700s by Vallisnieri (cited in 224) in Italy, followed by an extensive review and taxonomic description by Brauer (34) in Austria in the mid 19th century. Major contributions followed in England by Ormerod (157) and Imms (93); in the United States by Riley (179), Osborn (158), Bishopp et al (24), and Mote (132); and in Canada by Hadwen (85). Other reviews completed before the widespread use of systemic insecticides for cattle-grub control include work by James (94) and Scharff (185) in the United States, Gansser in Austria (69), Gebauer in Germany (70), Grunin in Russia (81), Natvig in Norway (141), MacDougall in Scotland (124), and Bevan & Edwards (22) in England. The quality of these reviews makes it unnecessary to repeat detailed information about the stage descriptions and life cycles for these two important species. Rather, I attempt to summarize these contributions, emphasizing additions to our knowledge since the 1950s