Monday, May 16, 2011

Cotton Thrips Pressure Heavy, Grasshoppers, and Other Cotton Insects

Cotton Thrips Pressure Heavy


Dry conditions in the coastal plain areas of Alabama and the Southeast have resulted in the migration of tremendous numbers of thrips from wild vegetation and small grains into cotton. All at-planting treatments, in cotton that was planted in April, are being overwhelmed by thrips numbers and injury. Sixty or more thrips can be found on 5 plants within one foot of row. The majority are in the adult stage but immatures are also being found this week.

Due to this continuous migration of thrips, foliar sprays are only holding for 3 to 5 days. However, these sprays are making a big difference from plants that are not receiving foliar applications. Foliar sprays to research plots that received no at-planting treatments have not been adequate in reducing severe thrips injury.

Several different chemicals are being evaluated as foliar sprays for thrips control. At this point, nothing has been as effective as our old standby acephate (Orthene), at 0.2 lb. per acre active.

Grasshoppers

Grasshoppers remain at high levels in the farmscape. Where they are present, controls would be advisable before cotton emerges. Grasshoppers are a threat to stands from the “crook” stage, as the plants emerge, up until about the 5 true leaf stage.

Other Cotton Insects

Ebony bug (Negro bug) immatures have been reported on young cotton in the Talladega County area. Chinch bugs and false chinch bugs have also been reported.