Wednesday, December 12, 2001 - 10:05 AM
0790

Using DNA microsatellite profiling to determine host selection by tsetse and stable flies: new insights into feeding behaviour and implications for biting fly control operations

Steve Schofield1, Adam Prior2, Steve Torr2, and Paul Wilson3. (1) Health Canada, Pest Management Regulatory Agency, 2720 Riverside Drive, Ottawa, ON, Canada, (2) University of Greenwich, Natural Resourses Institute, Central Avenue, Chatham Maritime, Kent, United Kingdom, (3) Trent University, 1600 West Bank Drive, Peterborough, ON, Canada

In Zimbabwe, field studies were made of the feeding behaviour of tsetse and stable flies attracted to small herds of cattle. The experimental herds comprised various combinations of calves (<100 kg), cows + steers (~300 kg) and oxen (>400 kg); the composition of the herds reflected the size, condition and age structure of herds found in the tsetse-affected communal areas of northern Zimbabwe. Blood meals from flies that had fed on animals from within the herd were extracted and DNA was amplified using primer sets for seven different ungulate loci. The resulting profiles were matched with those previously recorded from the individual cattle used in the experiment. Results indicated that feeding was greater on older and/or larger animals, even when a single large animal was surrounded by six smaller animals. For instance, in herds comprising a mixture of 2 oxen, 4 cow/steers and 2 calves, ~80% (range, 67% - 91%) of meals were from the two largest animals within the herd and only 0 - 3 % were from the calves. These findings indicate that the practice of not treating young animals, to allow the development of natural resistance to tick-borne disease, does not compromise the efficacy of using insecticide-treated cattle to control tsetse. Moreover, confining insecticide treatments to the larger adults will improve the cost-effectiveness of the technique

Species 1: (tsetse)
Species 2: (stable fly)
Keywords: microsatellites, feeding behaviour

The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA