Studies on the parasitic stages of the cattle tick. Boophilus Microplus (Canestrini) (Acarina: Ixodidae).

Abstract

Studies were made on infestations of Boophilus microplus (Canestrini) established by single applications of large cultures of larvae to cattle. The minimum duration of the larval stage was 4.5 days, and the maximum 13.1 days. Fifty per cent of the larvae had undergone ecdysis by 5.5 days after attachment. Nymphs commenced to moult 11.9 days after the attachment of the larvae to the cattle, and the last moulted 20.3 days after the infestation of the cattle. Fifty per cent of nymphs had completed the moult 13.9 days after attachment of the larvae. Male nymphs moulted, on the average, somewhat earlier than female nymphs. Adult males were still present up to 70 days after attachment of the larvae to the cattle. Engorged female ticks commenced to fall 18.9 days after the attachment of the larvae. Fifty per cent had fallen by 21.9 days, and the last fell at 35.5 days. Climate has little effect on the duration of the stages on cattle. A diurnal rhythm in the fall of engorged ticks was demonstrated, most ticks falling between the hours of 6.00 and 10.00 a.m. There is a considerable natural mortality of all stages of the tick on cattle. The importance of the life history studies to toxicological work is discussed.