On the longevity of fasting ticks, Hyalomma savignyi Gerv

Abstract

The survival of fasting imagines of Hyalomma savignyi under various conditions of temperature and relative humidity was studied.Within the range of experimental conditions low temperature and high humidity are shown to be most favourable to the survival of ticks: at 17·5° C. and 80–95% R.H. mean longevity approaches 1 year, and a few individuals were observed to survive for more than 2 years. Longevity shortens as temperature rises and relative humidity decreases. At a temperature of 37° C. (and under various conditions of humidity) average longevity does not exceed 1·5–3·5 months, while under conditions of extreme dryness, viz. 10–20% b.h. (and various temperatures) average longevity ranges from 1·5 to 9 months.The longevity of fasting imagines is not as much affected by dryness as that of preimaginal stages.