The life history of Corimelaena incognita (McAtee & Malloch) (Hemiptera: Heteroptera: Thyreocoridae) was studied in southern New Mexico from August 2005 through November 2007, and the immature stages were described. The bug also was reared from egg to adult under controlled laboratory conditions. Adults of this bivoltine species overwintered in leaf litter, emerged in early February, and began feeding on dried fruits of Leucophyllum frutescens (Berlandier) from the previous year, the only host plant observed for this bug; they and their offspring, collectively, fed on the current year's fruit throughout the season until early December. Eggs were found from early April through late September and laid singly, usually glued beneath the bracts of developing fruits. Nymphs were found from late April through late November. This species was reared in the laboratory on fruits of L. frutescens at 25 ± 0.01°C under a photoperiod of 14:10 (L:D) h. The incubation period averaged 8.33 d. The five stadia averaged 7.27, 4.10, 4.51, 4.90, and 8.54 d, respectively. Instars can be distinguished by differences in morphological features including, among others, body size and punctation.