Pictured are about 180 sugarcane aphids on a sorghum leaf well above the 50aphid triggertotreat number experts advise

Pictured are about 180 sugarcane aphids on a sorghum leaf, well above the 50-aphid trigger-to-treat number experts advise.

Sugarcane aphids are back in Central Texas and the High Plains

Sugarcane aphid numbers are low but scouting is recommended.

They’re back. Sugarcane aphids have been identified in the Texas High Plains and in West Central Texas in the past few days.

Texas AgriLife entomologist Pat Porter, Lubbock, “found a colony of sugarcane aphids on Johnsongrass near the Lubbock airport on Monday, June 29 after only 10 minutes of looking for the insects. An additional 30 minutes of looking resulted in no additional colonies being found. The aphid identification was confirmed by other Extension IPM personnel via digital photo.”

Porter says numbers remain low so far and sightings are not common. “Blayne Reed, Extension Agent IPM in Hale, Swisher and Floyd counties, and his scouts sampled two dozen sorghum fields on June 29 in Hale and Swisher counties and did not find any sugarcane aphids. Floyd County was not sampled. Kerry Siders, Extension Agent IPM in Hockley, Cochran and Lamb counties, spent time this week sampling Johnsongrass in Hockley and Cochran counties and did not find any sugarcane aphids.”

Porter said aphids identified in the Abilene area and southward last week were winged and are likely on their way north.
The Extension Entomology group on the southern High Plains; Blayne Reed, Tommy Doederlein, Kerry Siders and Pat Porter are putting together a two page guide on dealing with the sugarcane aphid on whorl stage sorghum. This guide will appear here in the next day or two and will include identification, scouting, treatment thresholds and insecticide suggestions.

For the latest on southwest agriculture, please check out Southwest Farm Press Daily and receive the latest news right to your inbox.

Other infestations identified

The aphid also has been spotted in West Central Texas, according to the following report by Texas AgriLife Extension media specialist Steve Byrns.

Byrns notes that Charles Allen, Texas A&M AgriLife Extension Service state integrated pest management leader at San Angelo, confirmed aphid presence in area sorghum. “Sugarcane aphid infestations of grain sorghum were found June 26 in Coleman, Runnels and Tom Green counties,” Allen said. “In all cases, the infestations had been present for less than a day to three days.

Allen said Michael Palmer, AgriLife Extension agent in Coleman County, identified the pest. Several more spot checks all proved positive.

“Sugarcane aphids do three things really well,” Allen said. First, they are capable of migrating long distances. Second, they have a very high reproductive capability and their populations can increase to damaging levels very quickly. And third, they produce large amounts of sticky honeydew, which negatively affects the host plants, the aphids’ natural enemies and our ability to harvest crops. The sticky residue, excreted as waste from the bug, gums up harvesting equipment and if heavy enough, makes harvesting all but impossible. Sticky leaves and stalks can actually choke down the equipment, be it a combine or hay swather.”

Scout weekly

Extension specialists recommend growers begin inspecting grain sorghum and forage sorghum crops weekly for the pest. Allen said producers should consider treating sorghum if sugarcane aphid levels exceed 50 aphids per leaf.

Complete sugarcane aphid scouting instructions are available.

Two insecticides have been found to be effective, Sivanto and Transform.

“The trouble is, it’s difficult for insecticides to work on thick vegetative growth in grain sorghum and especially in forage sorghum fields, because good spray coverage of the insects is essential,” Allen said. “On large stands of forage sorghum, cutting the crop for hay may be a better option.”

Frequent rain across most of Texas and early summer suppressed the sugarcane aphid in South Texas but also delayed cotton planting in many areas forcing many farmers to plant sorghums instead, which increase potential for sugarcane aphid infection.

Sugarcane aphid, first discovered in Florida in 1977, has historically been a pest of coastal sugarcane crops, but was never seen to damage Texas sugarcane. For some reason, it acquired a taste for sorghum with the first documented instance occurring near Beaumont in 2013, Allen said.

“Since that first sighting, things started happening fast; populations literally exploded during the fall of 2013-2014 and then again last year,” he said.

“We’ve learned a lot since that first sighting, specifically, that the best defense is an aggressive offense, starting with field scouting. Check at least 20 plants in four locations in each field, whether it’s grain sorghum or forage sorghum for that 50-aphid threshold. If the majority of the plants in a field are sticky and shiny with honeydew, you’ve already exceeded that threshold…by a lot.

“So get out in your fields at least once a week now and have a good look around, because they’re here.”

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