Cotton losses to arthropod pests reduced U.S. cotton yields by 2.72 percent in 2013, a slight increase over the previous year, but continuing a trend of low percent losses since 2000, according to a preliminary survey presented at the 2014 Beltwide Cotton Conferences, in New Orleans, La.
Total costs and loss for arthropods in 2013 was $716 million. Direct management costs for arthropods averaged $62.59 per acre. Loss plus cost averaged $90.75 per acre.
According to Cotton Insect Loss Estimates for 2013, compiled by Michael Williams, Extension entomologist for Mississippi State University, no single pest caused more than 1 percent loss in 2013, although national averaged are skewed by extremely low losses in Texas, where almost half of U.S. cotton was produced in 2013. The state reported a 0.74 percent loss to arthropod pests in 2013.
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Thirteen of the remaining 16 cotton producing states reported losses to pests exceeding 3 percent.
Nationally, Lygus, was again the No. 1 pest of cotton, according to entomologists, causing 0.788 percent in losses. In the Mid-South, Mississippi, Arkansas and Missouri reported losses exceeding 4 percent. About 37 percent of the acres in the United States are infested with Lygus. Virginia and Oklahoma reported no losses to Lygus in 2013.
Stink bugs were second at 0.681 percent loss and thrips were third, reducing yields by 0.557 percent.
About 54 percent of U.S. cotton acres are infested with stink bugs, according to the report. “Stink bugs are generally heavier in the Southeast states. Arizona had a high number of brown stink bugs in 2013,” Williams said.
Meanwhile 84 percent of U.S. cotton acreage is infested by thrips, the survey said, with only a small percentage of states reporting heavy losses. Tennessee reported 3.4 percent loss to thrips this year. Only two states reported no losses to thrips in 2013, Louisiana and California.
Cotton fleahoppers were the fourth most damaging pest in 2013, the survey said. They primarily infested the middle-western states of Oklahoma, Kansas, Texas and New Mexico. About 22 percent of U.S. acres were infested. Mississippi reported some losses as well. Five states lost bales to fleahoppers in 2013.
Heliothine losses continue to decline across all states, due to the influence of Bt cotton. “About 36 percent of cotton acres are still infested with some form of Heliothine. Surprisingly, New Mexico reported a 4.0 percent loss to bollworms.”
Alabama, California, Louisiana, Kansas, Missouri, Oklahoma and Virginia reported no losses to Heliothines in 2013.
Williams noted that Bt cotton acres declined in 2013, to about 6.5 million acres, “but that’s because cotton acreage is down to about 7.5 million acres. About 82 percent of U.S. cotton acres was planted in Bt cotton in 2013.”
Spider mites were the sixth most damaging pests, according to the report, with 15 states reporting infestations, and 10 states reporting losses. “In years past, some of the insecticides that we placed in the systems flared them, and they continue to hang around.”
No other pest was reported with greater than 1 percent loss in 2013, Williams said. “Clouded plant bug is almost a localized pest in Tennessee, Mississippi and Florida. We had infestations in eight states, with 492,000 acres infested. We lost only 7,000 bales to them.”
Between 3 million acres and 4 million acres of cotton were infested with aphid in 2013. Six states reported losses.
Williams noted that silverleaf whitefly “is another localized pest with six states reporting infestations. Only three states lost bales to the pest.”
Even though boll weevil has not been a part of the overall pest conversation for the past few years thanks to boll weevil eradication efforts, it still manages to raise a fuss, noted Williams.
“We finally settled on a number of 8,500 acres infested in south Texas. But I got an e-mail yesterday indicating that as many as 15,000 acres were infested. Hopefully, one day we’re going to be able to report boll weevils on zero acres.”
In 2002, 2.2 million acres were infested with boll weevils. Infested acres dropped to 116,247 in 2009. Eradication costs for boll weevil were $3.04 per U.S. acre in 2013. Eradication costs range from a high of $8 per acre in Arkansas, to 85 cents per acre in Georgia.
A little over 30 arthropod pests are reported each year in the survey, according to Williams. Final insect losses for 2013 will be posted by the end of January.