Temperature and Humidity Effects on the Life Cycle of Haemaphysalis Spinulosa and Rhipicephalus Simus (Acari: Ixodidae)

The biology of Haemaphysalis spinulosa and Rhipicephalus simus was investigated under laboratory and field conditions. Developmental and feeding periods were determined, as was reproductive capacity. The developmental periods of both ticks were not affected by relative humidity but were inversely related to temperature. The development of R. simus was faster than that of H. spinulosa and proceeded well at temperatures ranging from 15 to 38°C. The allowable temperature range for H. spinulosa was much narrower than that for R. simus. Haemaphysalis spinulosa entered diapause at low temperatures (15–18°C) and suffered considerable mortality at 38°C. The effect of narrower temperature preference on the distribution of H. spinulosa is discussed.