In 2012, Cotton Belt entomologists reported the lowest percent loss to insects since annual surveys of Cotton Belt entomologists began 33 years ago, according to entomologist Mike Williams, who compiles the annual survey, Cotton Insect Losses.
Across the Cotton Belt, insects caused an average 2.06 percent loss per acre. Williams said entomologists estimated management costs of insects at around $51.39 per acre. Cost plus loss was $71.18.
Louisiana reported the highest loss to insect pests in 2012, at 8.95 percent, while New Mexico reported the lowest, at 0.001 percent.
The lowest average cost of insect management occurred in 2009, when growers spent an average of $43.79 per acre, while 2000 was the highest cost ever reported, at $117.32.
The highest loss to insects ever came in 1995, when Heliothines (primarily tobacco budworms) caused 11.08 percent damage to the crop. The following year, Bt cotton was introduced, and a few years later, boll weevil eradication.
The year 2001 was somewhat momentous, noted Williams. “It marked the time when we began the trend to low, loss percentages. Bt cotton and eradication really dropped those percentages down to where they are reflected today.”
The survey for insect losses began in 1979. Cost of management was first reported in 1986.
Lygus, or plant bug, was the No. 1 pest of cotton in 2012, according to the survey, with losses of 0.695 percent. The pest infested about 45.5 percent of U.S. acres in 2012.
The Mid-South growing region has historically been a hot spot for plant bug. Louisiana reported a 3 percent loss to the pest in 2012, Mississippi, 4.7 percent, Arkansas, 4 percent, Missouri, 4 percent and Tennessee, 3.3 percent. Lygus lineolaris is the primary pest of the Mid-South and lygus hesperus is a formidable pest in Arizona and California.
The No. 2 insect, stink bug, caused a 0.375 percent loss and infested about 39.1 percent of U.S. acres. The Southeast was a hot spot for stink bug infestations, along with Arizona, which reported a 3 percent loss to the pest.
Thrips were the third most damaging pest, with a loss of 0.374 percent. About 70 percent of U.S. acreage was reported infested. “Most years we see this pest on nearly 100 percent of the acreage,” Williams said. “Usually there’s not very much loss. No state really had a tremendous amount of loss in 2012.”
Heliothines were the fourth most damaging pest, with 0.188 percent loss, according to the survey. About 88 percent of that population was the cotton bollworm. Almost 52 percent of U.S. acres were infested. “We had fairly low numbers in each of the states. Five states reported no infestations of Heliothines,” Williams said.
Williams noted that 11.2 million of the 12 million acres of cotton planted in 2012 contained the Bt trait. The average cost of Bt cotton was about $15.74 an acre.
Cotton fleahoppers were the next most damaging pest, with 0.152 percent losses, according to the survey. “This is a pest that we see primarily in Texas, Kansas and Oklahoma,” Williams said. “For the last few years, Kansas has reported a little over 1 percent damage from cotton fleahopper.”
The cotton fleahopper was found on about 39.4 percent of U.S. cotton acres. About 4.976 million acres of cotton was infested in 2012, with about 3.6 million of those acres in Texas.
The sixth most damaging pest, spider mite, is mostly a Mid-South pest and caused a 0.147 percent loss in 2012. About 29 percent of U.S. cotton acres were infested, “and we only lost about 63,000 bales.” Four states reported no losses to spider mites this year.
Silverleaf whitefly is mostly seen in the West, but did cause damage in Georgia in 2012. Only about 20,000 bales were lost to this pest, which infested 596,499 acres. Losses were 0.058 percent.
Aphids were the next most important pest, damaging 0.0383 percent of the crop. “Typically aphids appear most years in most states. In 2012, two states did not report infestations. On average, it was a light aphid year,” said Williams.
Pests in the “other” category caused losses of 0.01 percent. About 1.04 million acres were infested by pests in this category.
The clouded plant bug was the next most damaging pest, at 0.0319 percent losses. The survey reported that 761,000 acres were infested by clouded plant bug, mostly in the Mid-South. A little over 3,000 bales were lost.
The United States is still reporting losses to boll weevil, primarily along the Rio Grande River. “We were about to declare the United States boll weevil free this year, but there are still some acres infested, around 20,000 acres to 25,000 acres. No bales were lost to the pest.”
The average U.S. cost of boll weevil eradication is $3.60 an acre, according to the survey. “One area in Texas is paying about $19 an acre, and Arkansas is paying between $12 and $13 an acre. The low is about 50 cents an acre in Virginia.” Growers paid an average of 33 cents an acre for pink bollworm eradication.
Williams said the low damage levels are an indicator that pest management is working well in the United States. “I think it’s important that we continue to be aware of the new and potentially dangerous pests that are coming, but we are doing a good job on pest management.”
A total of 33 arthropods were listed in the 2012 survey.