Boll weevils in Arizona overwinter in accumulated leaf litter of plants along rivers and washes. Up to 14,000 weevils/ha were found under Tamarix aphylla. Weevils may also overwinter encased in dry bolls on standing stalks or on the ground. Weevils that emerged from the dry bolls were held in a 32 C incubator with water but no food. Weevils emerging in the fall or winter had 90% mortality within 2 weeks, but 10% of the weevils that emerge from the bolls in April survived longer than 40 days.

Over wintered weevils are trapped in greater numbers during the winter months with the lowest captures occurring in July. If the weevils trapped from Mar. 1 through June are considered to be overwintered weevils, then the time of 50% emergence may vary by one month between locations in Arizona.