Cotton insect losses down, but control costs up


U.S. cotton producers lost 3.01 percent of their crop to insects in 2011, one of the lowest percentages since entomologists began reporting losses 32 years ago, according to a preliminary report of Cotton Insect Losses 2012, compiled by entomologist Mike Williams.

The report said management costs are up about $10 an acre from 2010, at $62.25. Costs plus loss came in at about $100 per acre, compared to $91 per acre in 2010.

Williams said that costs plus loss trended higher from the 1970s to about 2000, then started a sharp decline. “It looks like we may have bottomed out in 2009, then in 2010, we started back up. The trend is still low, which is good for farmers.”

Williams said anytime total insect losses fall below 4 percent, producers have done a good job of managing pests. “It really is a credit to all of the industry and entomologists in that we are able to keep it that low.”

The data, gleaned from surveys of cotton entomologists across the Cotton Belt, was presented at the 2012 Beltwide Cotton Conferences in Orlando, Fla.

Lygus, or tarnished plant bug, was the No. 1 cotton pest in 2011, supplanting the bollworm/budworm complex, which led the field in 2010. Losses to Lygus totaled 1.03 percent. That’s about one-third of the losses reported, according to Williams. “About 50 percent of U.S. acres are infested with Lygus. California reported losses of 3.8 percent, which is pretty high for them. The majority of the losses were reported in California, Tennessee, Arkansas, Louisiana and Mississippi.”

Thrips were the second most-damaging pest in 2011, according to the preliminary data. “This year, the acres infested are down a little bit, from what is usually over 90 percent of the total acres, to 83 percent. Kansas, Tennessee and Virginia reported the highest losses to thrips. But it’s still less than 1 percent, 0.69 percent.”

Stink bugs No. 3

Stink bugs were the No. 3 most-damaging pests, the report said. “One again, these pests are concentrated in the Southeast. North Carolina, Florida and Alabama reported the highest losses. A number of states reported no infestations high enough to cause losses. About 47 percent of U.S. acres were infested with stink bug in 2011, and losses were 0.5 percent.”

Heliothines were the fourth most damaging pest for U.S. cotton producers in 2011, at 0.38 percent loss, according to the survey. It’s been a long time since the worm complex has fallen this low, according to Williams. “Hopefully, this is a trend we’re going to see continue. Fifty-six percent of the acres were infested with heliothines. Tennessee and Arkansas were the highest-loss states, and Louisiana was third.”

Much of the reduced loss to heliothines was due to the 8.9 million acres planted to Bt technology, noted Williams. “Bollgard II was planted on 6.9 million acres, while WideStrike cotton was planted on 1.9 million acres.”

Spider mites were the fifth most-damaging pest in 2011, Williams said, at 0.167 percent loss. “Spider mites infested about 42 percent of our acres, and 57,000 bales were taken by the pest. States that did not report losses to spider mites were Florida, Virginia, Kansas, Oklahoma and New Mexico.”

Flea hoppers, the sixth most-damaging insect at .05 percent, were concentrated in Kansas, Oklahoma and Texas in 2011, although losses were also reported in Mississippi and Arizona.

Clouded plant bugs took 10,000 bales in two states, Mississippi and Tennessee, while no other state reported losses.

Eight states reported no losses to aphids in 2011, according to Williams. “About 6 million acres were infested with aphids in 2011.”

Silverleaf whitefly infested a little over 600,000 acres in 2011, the report said, and produced losses of 10,000 bales. “This is one of those pests that we see mostly in the West, and there are some reports of losses in Texas and one report in Georgia.”

A long-time inhabitant of both cotton fields and the Cotton Insect Losses report, boll weevil, continues to slide into obscurity. “But we’re still paying an average $4.44 an acre across the Cotton Belt for boll weevil eradication and/or management. Texas is the only state that had acres infested with boll weevil in 2011. Texas reported no lost bales.”

Losses to other insects took nearly 55,000 bales in 2011, the report said. “There are four or five different critters.”

There were 32 insects rated in 2011, but 13 of them contributed less than 0.01 percent losses.