INFLUENCE OF ANNUAL AND BIENNIAL PRESCRIBED BURNING DURING MARCH ON THE ABUNDANCE OF AMBLYOMMA-AMERICANUM (ACARI, IXODIDAE) IN CENTRAL GEORGIA

A 5-yr study to evaluate the influence of annual and biennial prescrib ed burning in March on the abundance of Amblyomma americanum (L.) was conducted on Oconee Wildlife Management Area in the Piedmont physiogra phic region of Georgia. Tick abundance on plots embedded in larger bur ned and unburned areas were monitored with cloth drags and CO2-baited cloth panels monthly during March through September from 1987 through 1991. Annual and biennial prescribed burning from 1988 to 1991 signifi cantly reduced the abundance of larvae, nymphs, and adults but did not alter their seasonal trends of abundance. Annual burning more consist ently supressed all life stages than biennial burning. The magnitude o f tick supression tended to increase with sucessive burns, especially with the annual burning regime. The order of vulnerability to direct i ncineration appeared to be overwintered larvae > adults > nymphs; howe ver, only overwintered larvae were highly vulnerable. Consistent reduc tions in larvae during June-September following burning were associate d with reduced litter depths and presumably lowered habitat suitabilit y. During years of fire omission, the abundance of larvae on bienniall y burned plots increased to levels equal to or exceeding those on unbu rned plots. Based on cloth drag sampling, mean percentage control duri ng 1988-1991 for larvae, nymphs, and adults, respectively, was 80, 75, and 70% on annually burned plots and 48, 73, and 65% on biennially bu rned plots. Frequent late-winter prescribed burning, which is commonly used to achieve wildlife habitat management objectives, could be an e ffective and economical component of an integrated A. americanum contr ol program in habitats ecologically suited to regimes of frequent fire .