Late fall and midwinter disking of piles of cotton bolls that contained diapausingBracon mellitorSay were investigated as methods to increase overwintering survival and to delay spring emergence. In one year, disking in early December significantly increased survival of females; but in the second year disking did not influence survival. Spring emergence was completed in April and was not affected by December or February disking treatments. In another study, winter survival was increased and spring emergence was delayed by holding bolls in complete darkness at about 10°C. The parasitoids were held under these conditions for 6 mo, and then they were exposed to long daylengths (>13.5 h) and warm ambient temperatures in an outdoor insectary. Emergence began in late June and winter survival was 51.9% compared with 3.7% survival and emergence in April from bolls left on the soil surface.