Population estimation of the horse fly, Tabanus abactor (Diptera: Tabanidae), in northcentral Oklahoma.

A mark-recapture technique was used to estimate daily populations of host-seeking Tabanus abactor Philip. Daily population estimates were calculated for 31 and 37 d for areas of 2.1 km2 and 4.6 km2 for 1982 and 1983, respectively. In 1982, population estimates ranged from 22,767 to 2,125,322 flies/2.1 km2 per d with a mean of 467,277 flies/d. In 1983, population estimates ranged from 48,962 to 2,794,389 flies/4.6 km2 per d with a mean of 759,616 flies/d. The estimated average number of host-seeking females per hectare was 2,225 (0.22 flies/m2) and 1,651 (0.17 flies/m2) for 1982 and 1983, respectively. Although daily population estimates fluctuated greatly, primarily because of fluctuation in recapture rates, seasonal trends during both years were similar. The estimates calculated in this study appear to be representative of the population of T. abactor in northcentral Oklahoma based on previous studies determining seasonal abundance.