V. Cotton Insects

P. M. Roberts, W. R. Lambert, G. A Herzog and J.R. Ruberson

The Georgia Agricultural Statistics Service reported 1,490,000 acres were harvested in 1995 with an average yield of 625 lbs. lint per acre. Prices were favorable; the average price received for the 1995 crop was estimated at $0.7620 per lb. of lint (July 1, 1996). The 1995 season was interesting with suspected resistance to pyrethroids in tobacco budworm, two emergency exemptions for new insecticides, a new armyworm species feeding on cotton and lots of old favorite pests.

The 1995 season started dry -- like 1994, but we did manage to get much of the April and early May cotton up. Rain in early July brought the rest of the May plantings to a stand, and some cotton was planted into July. Drought returned by late June and continued through the summer in many areas. Eastern counties got some much needed late season rain from several tropical storms that brushed the coast. Record high temperatures through July and another spell in August were tough on non-irrigated acreage.

The first tobacco budworm moth flight was light to moderate, and control was relatively easy. The second flight over the Fourth of July proved to be much heavier and more difficult to control. Many factors can contribute to the control problems we experienced, but a number of facts point to resistance and spotty, heavy infestation as major players. In some areas, the bollworm/budworm pressure remained high through July and well into August.

Beet armyworms were found in cotton in May, but infestations did not develop into damaging numbers until July, and then only in limited areas. Where they did get bad, they got really bad, and caused a few growers to abandon fields. Confirm - used under emergency exemption, did a good job. Where intensive spraying was not needed for other pests, the parasite, Cotesia, kept beets in check through the year. Fall armyworm outbreaks were reported in many areas, but east Georgia was hardest hit. Soybean loopers were worse in >95 than in recent years. Two late season generations defoliated a lot of cotton because we do not have any effective insecticides against this pest. Yellowstriped armyworms also were more numerous this season and remained in cotton through July. The southern armyworm appeared in June as 1995's Anew@ pest.

A statewide aphid outbreak in June continued into July before the fungus disease wiped it out. Unfortunately, many fields were sprayed for aphids which may have contributed to some of the armyworm problems. Whiteflies developed late in the year, as did limited spider mite problems. Stink bugs also became a problem in several areas late in the season.

The Boll Weevil Eradication Program continued to make progress toward getting the last boll weevil in Georgia. Northwest Georgia appears to be nearing eradication and the Elbert County outbreak of 1994 has been cleaned up. The BWEP reacted quickly and effectively to a Brooks County problem, trapping and spraying intensively to prevent its spread.

The tremendous acreage increase caused a number of problems that will be corrected in time. Shortages of experienced scouts, chemicals, and rain and an abundance of insects and high temperatures all combined to make 1995 a tough year to begin growing cotton.

Estimates of Losses and Control Costs

¹Grower costs of Boll Weevil Eradication Program (BWEP).

Information Pertaining to Control of Major Cotton Insect Pests in Georgia in 1995

¹ Including application costs.
² Yield units measured in pounds of lint.
³ Grower costs of eradication program. All cotton produced in Georgia is required to participate in the Boll Weevil Eradication Program. The annual per acre assessment for participation equaled $5.50 per acre in 1995. A minor outbreak of boll weevil was detected and treated in Brooks County. Infestations were confined to about 12,000 acres.