Effects of temperature and relative humidity on the egg laying pattern of Rhipicephalus sanguineus (Koch, 1844) infesting sheep in semi-arid region of Nigeria

The ovipositional pattern of fully engorged adult female Rhipicephalus sanguineus infesting sheep was studied under belljar conditions of mean ± SD (range) temperature of 25.4±2.16 (23-29oC) and relative humidity 90% and ambient conditions of 26.4±2.4 (23.6-31.6oC) and relative humidity 63.0±3.93 (51.3-72%). The pre-oviposition days under belljar conditions (11.1±9.15) was significantly shorter (p<0.05) than ambient conditions (14.5±14.9 days), each having post oviposition weights of 0.11±0.04 grams and 0.17±0.012 grams respectively, indicating a decrease in weight of the ticks after oviposition. The mean ±SD oviposition period (days) was shorter (p>0.05) under belljar (22.3±9.69) than ambient (23.7±10.7) conditions with the total mean ± SD number of eggs laid under each condition as 1021.9±1082.4 and 1096.9±1173.0 respectively (p<0.05). The peak oviposition period was day 13 for belljar and day 16 for ambient conditions each with mean ± SD egg lay of 2100 and 2260, and peak total of 3936 and 3610 eggs respectively. It is concluded that the ovipositional behaviour of Rh. sanguinues could be influenced by temperature and humidity changes.