The ecology and behavior of the lone star tick (Acarina: Ixodidae). VII. Pre- and post-molt behavior of engorged nymphs and larvae.

Abstract

Engorged larval and nymphal ticks [Amblyomma americanum (L.)] were released periodically during the spring and summer of 1972 and 1973, and observations were made to determine molting time, preactivity time, and post-molt activity in 2 contrasting habitats in Cherokee Co., Oklahoma. Environmental parameters, including stratified temperatures above the soil surface and relative humidity, were also recorded. Engorged nymphs and engorged larvae had limited mobility after release and sought shelter in plant litter and debris near the point of release. During 1972 and 1973 nymphal molting time ranged from 16 to 58 days and 30 to 66 days, respectively. The post-molt developmental phase. (period between ecdysis and initiation of activity) ranged from 8 to 15 days in the March, April, and May releases. Those ticks molting after mid-July remained inactive until the folIowing spring. In general, molting times in the meadow habitat were shorter than those in the upland oak-hickory habitat. All ticks molted prior to the onset of winter. Of those nymphs molting to adults prior to 15 July, only 20% in the meadow and 7% in the upland oak-hickory habitats became active the first season. Engorged larvae required less time to molt than engorged nymphs. During 1972 larval molting time was considerably shorter in the meadow than in the upland oak-hickory, where it ranged from 11 to 33 days. During 1973 there were fewer differences in molting times between the 2 habitats, but activity of the resulting nymphal ticks in the meadow was 30–50% shorter than in the upland oak-hickory. After ecdysis nymphs remained active until October, at which time they quiesced.