The longevity of 452 adult virgin females of Dysdercus mendesi Bloete was studied under laboratory conditions, from April 28 to October 2, 1936. A study of the temperature records corresponding to this period showed marked influence of this factor on the insect longevity, mortality and life expectation. The mean longevity was 24.25 days for the entire population, when the mean of the temperature recorded was 19.2(0)C; for temperature averaging 15 to 18°C the longevity was 26.41 days (192 females studied) and for 21-23°C the mean longevity decreased to 14.05 days (42 insects). The survivorship curve for the entire population was apparently normal.