Terry Pitts, Oklahoma Cooperative Extension Service integrated pest management specialist, said fleahoppers need to be controlled when thresholds are exceeded to protect beneficial insects that help control cotton pests that appear later in the growing season.

After July 25, the control of cotton fleahoppers generally is not economical because of Oklahoma’s short growing season.

“We’re currently at the four- to eight-leaf stage on cotton in Oklahoma, as well as being at 817 degree days,” Pitts said. “Some of the early planted cotton has pinhead to matchhead squares. If you normally make your fleahopper insecticide application at the pinhead growth stage, the week of June 23 could be the week to make the application.”

Spray decisions should be based on the squaring rate and level of fleahopper infestation.

“When cotton fleahoppers – adults and nymphs – reach or exceed 40 per 1,000 terminals, squaring rates usually begin to decline, justifying treatment,” Pitts said. “If fleahopper numbers build slowly, fields can tolerate high numbers of this pest before a reduction in the cotton plant squaring rate will occur.”

Once they begin to bloom, cotton fields will no longer be vulnerable to fleahoppers, in most cases.

Chemicals approved for use to control cotton fleahoppers include Bidrin®, Dimethioate® (Cygon), Centric®, Intruder®, Orthene®, Steward®, Thiodan®, Trimax® and Vydate®.

“Consult your local OSU Cooperative Extension county agricultural educator on which chemicals are likely to work best,” Pitts said. “Also, always review a chemical’s label for details, restriction and limitations.”