The effects of several environmental factors on mortality of adult Culicoides variipennis in the laboratory were evaluated. Daily mortality rates significantly increased when adult midges were maintained at an elevated constant temperature (26 degrees C). Adult C. variipennis handled the least during routine maintenance procedures had the lowest daily mortality rate. Survival was not significantly affected by varying density levels of adult midges in the size of container routinely used in our laboratory. Implications of these observations using adult C. variipennis for future studies are discussed.