Abstract: A laboratory study was conducted on the influence of temperature, air relative humidity and water presence on some biological parameters of Clavigralla tomentosicollis Stal, a major pest of cowpea, Vigna unguiculata Walpers, in West Africa. The feeding of the first-instar larvae was also studied. The aim was to provide some indicators on the insect adaptation to hot and dry conditions in Sahelian zone. Results show that increased temperature reduced embryo and larvae development length and female fertility and lifespan. Temperature fluctuations had little effect on egg viability to the extent of hatching limit around 38 ° C. A full larval development and adult reproductive activity were possible at a constant temperature of 40 ° C. Increased air relative humidity (80%) improved larval survival especially under high temperatures. The presence of water was necessary for first-instar larvae development. The insect showed good adaptation to Sahelian hot and dry environment, which enables it to go through the long dry season.