ST. LOUIS, Mo. — Stink bugs in soybeans, sugarcane aphids in sorghum and all manner of cotton bugs – Southern producers are dealing with plenty of pest concerns as row crops grow, but specialists say good scouting and management can help keep pest headaches at bay.

Sugarcane aphid populations approached threshold levels in sorghum fields in eight Tennessee counties as of July 30. That included the westernmost five of the southern tier of counties, from Shelby County east to Hardin County. Dyer, Tipton and Haywood counties also had fields approaching threshold levels.

Scott Stewart, University of Tennessee integrated pest management specialist, cautioned producers to not ignore aphid populations – but also not to overreact.

“Finding sugarcane aphids in an area does not mean every field in the county needs an insecticide application,” he said, writing on the UTcrops News Blog. Sugarcane aphid populations can change quickly, so specialists encourage close scouting to determine if and how to treat.

Sorghum producers farther south, from Texas to Alabama, have battled the aphid, which can prevent sorghum from heading. Heavy aphid infestations can produce enough honeydew to even gum up harvesting equipment, according to Dominic Reisig, entomology extension specialist at North Carolina State University.

Sorghum plantings increased in both Tennessee   and North Carolina this year, as row crop farmers saw some profit potential in light of lower corn and soybean prices.

Sugarcane aphid was confirmed or suspected last week in all counties in West Tennessee, from Lake County and Obion County moving southeast through Gibson, Henderson and Hardin counties. Sugarcane aphid also posed a puzzle for sorghum growers making spray decisions for other possible sorghum pests, like corn earworm, fall armyworm and sorghum headworms.

Stewart encourages growers to only treat these pests when populations reached threshold levels. He also encourages avoiding pyrethroid insecticides, if possible, as pyrethroids can kill off insects that naturally prey on aphids.

“A sorghum crop can become pretty expensive if we blindly apply $40 to $50 of insecticide and fungicide on every acre,” he said.

Sorghum acres increased in Tennessee this year as farmers were attracted by low production costs relative to corn, and potentially positive economic profits, because of strong sorghum exports.

Soy and cotton pests

One black light trap at the Western Kentucky Research and Extension Center, in Princeton, captured more stinkbugs through mid-July than two traps captured during all last year.

That should give soybean producers warning, reported Doug Johnson, University of Kentucky entomologist. “We expect stinkbugs to begin moving into soybeans as plants begin to bloom,” he stated in a July 21 update.

Late-planted soybeans are more susceptible to stink bugs. “Soybeans planted at the normal planting dates are much less likely to suffer economically important damage than are later planted beans,” said Johnson.

Stink bugs are also an issue for Tennessee’s cotton acreage, which caught up on accumulating heat units in July. “Plant bugs continue to be an issue for many, but pressure seems normal for our area,” said Tyson Raper, UT cotton and small grains specialist, based in Jackson.

Thrips, tarnished plant bugs and clouded plant bugs are other important pests for Tennessee cotton growers. Scouting the cotton crop for the number of nodes above first-position white flowers, or NAWF, remains part of the essential cotton insect management strategy, said Stewart, who posted reminders about cotton insecticide treatments at www.utcrops.com