Fields that have received little or no insecticide treatments recently should be scouted carefully for stink bugs and plant bugs. Whitefly infestations are building, particularly on fields that received applications of ULV Malathion earlier in the season. There are two materials that are still listed in the Cotton Insect Control Guide that belong to the chlorinated hydrocarbon class of chemistry, the same class as DDT, Endrin, Dieldrin, etc. During the 1998 season bandedwinged whitefly populations built to high levels in most fields that were involved in boll weevil eradication efforts. Whitefly populations are building again this year, especially in fields that received earlier applications of ULV malathion.
Whiteflies can be very difficult to control and populations can rebound quickly following treatment.
When attempting to suppress whitefly populations with most currently available materials, Orthene or Monitor, it is important to apply two or more successive treatments on a 5-day interval. The follow up application is needed to control those adults that emerge after the first treatment before these adults have the opportunity to lay many eggs. In past years the importance of stink bugs as a pest of Mississippi cotton has been masked by the large number of treatments applied for control of other pests. However, now that boll weevil eradication has progressed to the point that some fields are no longer requiring treatment for weevils and Bt-cotton has eliminated the need for most worm treatments, damaging populations of stink bugs are appearing in some Mississippi cotton fields. Stink bugs are normally more numerous following a mild winter and a few fields have already required treatment this year.