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Cotton Insect Threshold Chart

I wanted to provide a quick reference chart for common pests in cotton and recommended treatment thresholds.  I hope a condensed chart will be useful and save time.  Please refer to the Georgia Pest Management Handbook for cotton insecticide options or call our office at 263-4103 or my cell phone @ 305-7047.

PEST THRESHOLD
Aphid (Cotton) Apply when aphids are abundant and seedling leaves are severely curled, or when “honeydew” is present in older cotton.
Beet Armyworm Apply when 10% of squares are damaged, 10% of blooms are infested, or when 10 active “hits” are observed per 300 row feet.
Bollworm/Tobacco Budworm Apply insecticide on Bt cotton when 8 larvae (1/4 inch or greater in length) are found per 100 plantsOn non-Bt cotton apply when 8 small larvae are found per 100 terminals prior to first insecticide treatment, or when 5 larvae are found after first spray.
Cutworm Apply when stand is threatened. Spot treatment is often adequate.
Plant Bugs/Flea Hoppers Apply when plants are retaining less than 80% of pinhead squares and numerous plant bugs are observed.
Soybean Looper Treatment is necessary when soybean loopers threaten to defoliate cotton with immature bolls.
Spider Mites Apply when mites are spreading. Spot treatment may be adequate.
Stink Bugs Use a 10-15% boll injury threshold during weeks 3-5 of bloom, 20% during weeks 2 and 6 and 30%(+) during weeks 7(+) of bloom. Detection of 1 stink bug per 6 row feet would also justify treatment.
Thrips Apply when 2-3 thrips per plant are counted and immatures are present.
Whitefly (banded winged) Apply when 50% of terminals in rapidly growing cotton are infested, or when honeydew is found on foliage or lint of older cotton with open bolls.
Whitefly (silverleaf) Silverleaf whitefly is difficult to control with insecticides. Early detection and conservation of natural controls are important.