Evaluation of injectable abamectin to control natural infestations of Haematobia irritans (Diptera: Muscidae) in cattle.
The effect of 200 micrograms/kg of body weight of injectable 1% abamectin to control Hematobia irritans (L.) was evaluated in heifers treated every 45 or 63 d versus control heifers. Fly numbers were estimated every 7 d with additional counts on days 1, 4, and 10 after treatment. Samples of feces were obtained up to 28 d after treatment from treated and control heifers to culture H. irritans in the laboratory. The H. irritans population reduction for 14 d after treatment ranged from 51% (3rd treatment of heifers treated every 45 d) to > 73% in the 1st treatments of both groups of heifers and the 2nd treatment of the group treated every 63 d. Medication every 45 d did not provide a better control than treatment every 63 d. The abamectin arrested the immature stages for 7 d after the 1st treatment; this period increased to 28 d after the 3rd treatment but its effect on heifer infestation was low, probably because of fly immigration. Abamectin may help maintain H. irritans populations below the threshold of economic damage.
Guglielmone
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AA
Departamento de Producción Animal, Estación Experimental Rafaela, INTA, Santa Fe, Argentina.
Volpogni
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MM
Anziani
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OS
Flores
S G
SG
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology / Q000517:prevention & control*; D004195:Disease Models, Animal; D005069:Evaluation Studies as Topic; D007267:Injections; D007300:Insect Control / Q000379:methods*; D007306:Insecticides; D007559:Ivermectin / Q000031:analogs & derivatives*; D009117:Muscidae; D009198:Myiasis / Q000517:prevention & control / Q000662:veterinary*
D007306:Insecticides; C048324:abamectin; D007559:Ivermectin