Sugarcane aphids, a serious threat to sorghum, have been confirmed in Ashley, Chicot and Desha counties in the southeastern corner of Arkansas.

Nick Seiter, extension entomologist for the University of Arkansas System Division of Agriculture, said the first reports of the insect in sorghum came in two weeks ago and were "mostly limited to small populations." No fields had been treated yet for the insects.

Ashley County Extension Agent Kevin Norton said that he found the pest last week in a field west of Hamburg. "Right now, the population is low," Norton said, "but as the population grows, it can be a real problem."

While Norton said that he is aware of only one grower in Ashley County, there is a substantial amount of grain sorghum just east of Ashley County in the area round the Boeuf River in Chicot County.

"In areas where sugarcane aphid has been found, sorghum needs to be scouted regularly, as this insect reproduces very rapidly and can be very damaging to the sorghum crop throughout the growing season," Seiter said. "Growers should be looking for the aphids themselves as well as sticky honeydew on lower leaves."

Sugarcane aphids were first spotted in Louisiana, Texas, Oklahoma and Mississippi in 2013. It was first confirmed in Arkansas last year.

"They have been developing in Texas and Louisiana over the last month or so, so they might have moved up" from there, Seiter said. "I suspect there were some small overwintered populations in southeast Arkansas, but it's impossible to tell how many of the aphids we are seeing now overwintered here versus flying up from the south."

The aphids excrete a sugary honeydew on sorghum leaves. Black mold can grow in the honeydew and reduce photosynthesis. If infestation is severe, the aphids can cripple or kill the plants.

Norton noted that the sticky honeydew is a menace during harvest, clogging up combines, along with any plants that have died and fallen over, a condition known as "lodging." He also said that if the aphid population is bad enough early, the aphids can kill the sorghum.

Norton said that the aphids are a very specific pest, and right now, the only crop the aphids bother in this area is grain sorghum. The aphids were first found in sugarcane, and they then adapted to become a pest for grain sorghum. Barring additional changes or adaptations, the aphids do not pose a threat to other crops but can also be found in johnsongrass.

Seiter asks that farmers who find sugarcane aphids email a photo and the location to an Extension entomologist, to enable them to keep an updated map of aphid infestations.

Source - http://www.ashleycountyledger.com/