Cotton Pest Management Newsletter #11
August 15, 2002

Cotton Situation: The Georgia Weekly Weather and Crops Report for the week ending August 11^th listed the crop as 13 percent with open bolls. Crop conditions continue to be highly variable. Thirty-six percent of the crop is rated fair, 38 percent good, and 9 percent excellent. The Boll Weevil Eradication Program certified the 2002 Georgia acreage at 1,439,887 acres.

Insect Situation: Tobacco budworm and corn earworm continue to be observed in many areas and infestations tend to be concentrated on green lush fields. Soybean loopers have been observed in the southern part of the state with a few fields requiring treatment. Aphid populations are building in isolated fields and silverleaf whitefly numbers appear to be increasing near Tifton.

Tobacco Budworm and Corn Earworm: In many areas of the state we have observed sustained pressure since early July. Infestations have been the highest and most consistent since 1995. Egg counts greater than 100 per 100 plants have been common in many areas. Additionally, pyrethroid resistant tobacco budworm is suspected statewide. Although some non-Bt fields have been treated only 1-2 times, 3-6 sprays is much more common. Insecticide selection and timing of applications has been and will continue to be critical for successful management.

Soybean Looper: Soybean looper (SBL) infestations have been reported in southwest Georgia. A few isolated fields have been treated to date but this is a pest which needs to be monitored closely in both Bt and non-Bt cotton. Loopers lay eggs individually on the underside of leaves. Upon hatching SBL larvae will feed for about 2 weeks prior to pupating. As larvae develop, the amount of foliage consumed per day increases significantly. Pupae are attached to the underside of leaves covered by a thin transparent webbing or cocoon. SBL feed almost exclusively on foliage and affect yield by prematurely defoliating cotton which still has immature bolls. In some situations, some feeding by SBL low in the canopy may actually benefit by allowing better air movement. Feeding is typically initiated low in the canopy and larvae tend to move up the canopy in time. Recommended treatments for loopers include Steward, Tracer and Larvin. Intrepid also has good activity on SBL.

Aphids: In isolated areas, aphid numbers appear to be building. A few reports of heavy honeydew accumulation on lower leaves have been received.

Silverleaf Whitefly: Whitefly numbers appear to have increased during recent days in the Tifton vicinity. We should anticipate economic infestations on late planted cotton in this area if dry conditions continue.

Insect Updates: Check the Cotton Insect Hotline (1/800-851-2847) for updates on current insect conditions. The Cotton Pest Management Newsletter is also posted on the Internet at "www.gaipm.org" and then click on "cotton".

Sincerely,

Phillip Roberts
Extension Entomologist