The results of a longevity study of 982 adult males of Dysdercus mendesi Bloete are presented; this population was divided in two groups: a) 722 virgin males, and b) 260 mated males. The study was done under laboratory conditions; however, the results were also grouped according to the average temperature under which the insects lived. A marked influence of temperature upon their longevity was noticed. For the entire population, the mean longevity was 31.28 days; the mated males lived an average of 32.05 days, and the virgin males 30.98 days. For temperatures averaging 15-18ºC the mated males lived 47.01 days and the virgin males 40.93 days. i.e. the mated males lived about 6 days more than the virgin males, under such mean temperatures. For temperatures averaging 18-20ºC, the mated males lived 37.34 days, and the virgin ones 26.64 days; for temperatures averaging 20-22ºC the mated males lived 21.96 days and for temperatures averaging 20-23ºC the virgin males lived only 14.82 days.