Seasonal Activity of Ticks (Acarina: Metastigmata) on Cattle in Southwestern Texas

Abstract

While on pasture at Camp Bullis, Texas, from November 1958 to February 1960 and thereafter at Kerrville, Texas, until March 1965, a small herd of Hereford cattle (28–86 animals) was examined monthly, and the numbers of adult ticks on an area of the dewlap and escutcheon of each animal were recorded. The lone star tick, Amblyomma americanum (L.), the most abundant species, was found on cattle throughout the year; some in February, rapidly increasing numbers until activity peaked in March–June, rapidly decreasing numbers through August, and a few ticks in September–January. Peak populations of adult lone star ticks, as determined by dragging pastures, coincided with peaks of infestations on cattle. The winter tick, Dermacentor albipictus (Packard), another abundant species, appeared first on cattle in October; activity peaked in November–January and decreased rapidly in February–March until almost no ticks were found in April–September. The black-legged tick, Ixodes scapularis Say, a less common species, appeared on cattle in October; activity peaked in November–December, a few ticks were found in January–March, and none were found in April–September. Ears of each animal were examined, and numbers of nymphal ear ticks, Otobius megnini (Duges), were also recorded; this species had an inconsistent peak of activity in the late summer-early fall, but the seasonal relationship was not so well defined as for the other species.