The bollworm/budworm complex retained its position as the nation’s No. 1 pest in cotton production in 2007, reducing yields by 0.91 percent, a slight increase over 2006, according to the publication, “Cotton Loss Estimates — 2007,” presented at the 2008 Beltwide Cotton Conferences in Nashville by Michael Williams, entomologist, Mississippi State University.
Total losses from all insect pests in 2007 were 3.61 percent. According to the report, losses below 5 percent “continue to reflect the outstanding contribution technology has made to managing pest complexes which long have plagued cotton producers.”
Bollworms were the dominant species (92 percent) of the heliothine complex in 2007. Heliothine damages resulted in the loss of 229,000 bales of cotton. South Carolina (4.5 percent) and Alabama (2.88 percent) reported the highest loss to heliothines, with Georgia (1.58 percent), Florida (1.28 percent) and North Carolina (1.04 percent) rounding out the top five.
Texas, which lost 78,000 bales, was the only state to report losses greater than 50,000 bales, according to Williams.
Bt cotton acreage decreased in 2007 to 7.1 million acres, although this was more reflective of the overall decrease in cotton acres, according to the report. Bt cotton comprised 65 percent of total acreage. Heliothine were sprayed with insecticide on 2.21 million Bt cotton acres in 2007. The cost of Bt is estimated at $10.40 per acre, which represents about 18 percent of the cost of insect management, and is second only to foliar applications at 47 percent of the cost.
Lygus, or plant bugs, were the second most damaging pest in 2007 with losses of 0.678 percent, or 170,000 bales. Louisiana (3.61 percent) and Missouri (2.04 percent) reported the highest losses. Arkansas, Mississippi and California reported losses of 1 percent or higher. All other states reported losses of less than 1 percent. New Mexico, Oklahoma, South Carolina and Virginia reported no losses to the pest.
Early-season thrips reduced the U.S. crop by 0.577 percent, making it the third most damaging pest. Thrips infested 89 percent of U.S. cotton acreage last year and cost farmers $7.54 per acre in management. Alabama (2.47 percent) reported the highest losses. Virginia, Florida, North Carolina and Tennessee reported more than 1 percent losses. Arizona reported no losses from early-season thrips.
Cotton fleahoppers were the fourth most damaging cotton pest in 2007 with losses of 0.477 percent. Texas (1.11 percent), Kansas (0.82 percent), Missouri (0.725 percent), Oklahoma (0.32 percent), Arizona (0.025 percent and Mississippi (0.004 percent) reported losses to the pests. All other states reported no losses.
Aphids ranked as the fifth most damaging pest with yield losses of 0.32 percent. California (0.84 percent), Texas (0.63 percent), Florida (0.22 percent) and Mississippi (0.1 percent reported the heaviest losses. The pest infested 64 percent of U.S. cotton.
Stink bugs were the sixth most damaging pest in 2007 reducing the crop by 0.273 percent. Florida (3.22 percent) reported major problems with the pest. Other states with losses were South Carolina, Alabama, Georgia, Tennessee, Mississippi, North Carolina, Missouri, Texas, Arkansas, Louisiana, Oklahoma and New Mexico. The stink bug complex infested 4.8 million acres of cotton in 2007 and destroyed 68,000 bales of cotton. Arizona, California, Kansas and Virginia reported no losses to the pest.
Spider mites infested 0.242 percent of the crop in 2007, good enough for seventh place. Mites infested 3.3 million acres of cotton in 2007. Only Missouri (1.09 percent) reported losses greater than 1 percent. California and Tennessee reported greater than 0.5 percent loss.
Silverleaf whitefly ranked eighth in losses with six states reporting infestations. Georgia lost 4,167 bales, Texas, 3,926 bales, California, 2,472 bales, Arizona, 2,353 bales and Florida, 833 bales. South Carolina reported infestations, but no losses.
Fall armyworms were the ninth most damaging pest reducing yield by 0.048 percent on 1.758 million acres infested. Florida, South Carolina, Georgia, Mississippi, Texas, Tennessee and Oklahoma reported losses.
Meanwhile, the most-feared cotton pest in history has been relegated to the “other pests of cotton” category. Boll weevils infested 2.211 million acres of cotton in 2002, dropped to 1.57 million acres in 2004, surged to 1.8 million acres in 2005, then fell to a paltry 612,193 acres in 2007. Only Texas reported lost cotton to weevils. Eradication costs for weevils amounted to $7.65 per acre.
Losses from all remaining pests were almost negligible, according to Williams. Combined they reduced cotton yield by 0.003 percent. The pests included European corn borer, beet armyworms, cutworms and loopers, bandedwinged whiteflies, cotton leafperforator, grasshoppers, saltmarsh caterpillars and southern armyworms.
Pink bollworm infested almost 90,000 acres of U.S. cotton in 2007. Arizona lost 425 bales to pink bollworm while Texas lost 28 bales. California reported infested acres, but no losses. Pink bollworm eradication cost U.S. cotton producers about 34 cents per acre in eradication costs.
Data for “Cotton Loss Estimates” were collected by coordinators in each cotton producing state. The Cotton Foundation supports the project.