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

Abstract

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 -29^oC) and relative humidity 90% and ambient conditions of 26.4±2.4 (23.6-31.6^oC) 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 o f 3936 and 3610 eggs respectively. It is concluded that the ovipositional behaviour of Rh. sanguinues could be influenced by temperature and humidity changes.