The budworm/bollworm complex retained its ranking as the top pest of U.S. cotton in 2002, reducing yields by an average of 2.29 percent, according to a survey conducted by Mississippi State University Extension entomologist Mike Williams. Results of the survey, Cotton Insect Losses, 2002, were presented at the 2003 Beltwide Cotton Conferences in Nashville.
Rounding out the top five were Lygus (plant bugs), stinkbugs, early-season thrips, boll weevils and aphids. None of these pests exceeded 1 percent in losses, however.
Total losses from insect pests in U.S. cotton were 4.79 percent in 2002, up slightly from 2001. The average cost of insect management was $60.67 per acre in 2002; costs plus losses was $88.80 per acre. When losses to insects and control costs are combined, U.S. growers lost nearly $1.2 billion to insects in 2002.
By state, Oklahoma reported the highest percent loss to pests at 9.4, followed by Alabama, 8.71; South Carolina, 8.52; Arkansas, 8.48; and Missouri, 7.81. Mississippi reported the most losses in terms of bales at 236,000, followed by Texas at 205,187.
The budworm/bollworm complex reduced yields by 2.29 percent, which was almost double 2001 losses of 1.23 percent. Almost 80 percent of the U.S. crop was infested with the pest, resulting in a loss of 665,712 bales. Bollworms made up 83 percent of the pest population in the United States. Arkansas, South Carolina, Missouri, Tennessee and Mississippi reported the largest percent losses to the complex.
Lygus, the second-most damaging pest infesting 54 percent of all U.S. cotton acreage, reduced yields by 0.78 percent, for a loss of 231,750 bales. Reporting the most damage to plant bugs were Alabama, 2.81 percent; Arkansas, 1 percent; Louisiana, 2.32 percent; Mississippi, 2.33 percent; Missouri, 0.97 percent; Tennessee, 0.71 percent; and Arizona, 2.91 percent.
Kansas, Oklahoma, North Carolina and Virginia reported no losses to Lygus.
Stinkbugs reduced yields by 0.52 percent across the United States. South Carolina, 2.39 percent; Alabama, 2.28; Florida; 1.4; Georgia, 1.29; and Tennessee, 0.89, were the biggest losers to stinkbugs. The complex infested 5.75 million acres of cotton in 2002 and destroyed 135,944 bales of cotton. California, Kansas, New Mexico and Virginia reported no losses to the pest.
Early-season thrips occupied more acres than any other pest and reduced yields by 0.43 percent, according to the survey. The pest infested 95.2 percent of U.S. acreage in 2002, costing farmers $5.18 per acre in management costs, and 129,044 bales of cotton. Virginia, 2.51 percent; Tennessee, 1.75 percent; Alabama, 1.71 percent; Oklahoma, 1.67 percent; and Missouri, 1.56 percent, reported heaviest losses from thrips. California, Georgia, New Mexico and South Carolina reported no losses to the pest.
Boll weevils continue to be a factor in insect losses, although losses continue to fade due to boll weevil eradication. Weevils infested 2.35 million acres of cotton in 2002, reducing yield by 0.221 percent. Only five states reported acres infested by the pest, Arkansas, Louisiana, Missouri, New Mexico and Texas. Only Texas and Arkansas reported losses.
Aphids infested 69.7 percent of U.S. cotton acreage in 2002, reducing yield 0.13 percent. Alabama, Missouri and Florida reported the heaviest losses. Seven states, Arizona, Arkansas, Kansas, New Mexico, North Carolina, South Carolina and Virginia reported no losses to aphids, while Kansas was the only state reporting no acres infested.
Texas reported the highest cost plus loss to insects in 2002, at a little over $190 million, followed by Mississippi, at nearly $180 million; Arkansas, $168 million; Georgia, $116 million; and Louisiana, at $92 million.
Entomologists also reported that a little over 5 million acres of Bt cotton was sprayed for caterpillars in 2002, compared to 5.7 million acres in 2001. This marks the first year-to-year decline in Bt acreage sprayed for the pest since the technology was introduced.
Other pests include cotton fleahopper, which infested more than 4 million acres in 2002, beet armyworm, spider mites, European cornborer, fall armyworm, cutworm, loopers, cotton leaf perforator, pink bollworm, grasshopper, saltmarsh caterpillar and Southern armyworm.