The prime location may be an older field within a community or a more mature portion of a particular field. Differences in the maturity of cotton within a field can be caused by a northerly windbreak, the early emergency of cotton in low parts of the field during dry springs, or by other factors. An overwintered boll weevil can survive for about 14 days after emergence on moisture alone. Survival increases substantially when terminals are available for feeding and even more so when squares are present. So, some weevils emerging in late May and early June may well lay eggs on into July if they are left uncontrolled.
Several factors form the basic philosophy for controlling overwintered boll weevils.
The overall goal is to delay insecticide applications until a high percentage of emerged weevils have located cotton. But these applications must be made prior to the one-third grown square stage, so that no eggs will have been laid. Ideally, this application occurs enough in advance of the tobacco budworm flight in June so that beneficial insects are not disrupted. The expected result of a well timed pinhead square application is not season-long control. Instead, this application is meant to reduce the numbers of first-generation weevils to manageable levels and to delay first generation controls by several days.