They’re back.

Sugarcane aphid numbers are increasing rapidly in grain sorghum fields across the Texas High Plains.

Dr. Ed Bynum, AgriLife Extension entomologist, says sugarcane aphid populations in the South Plains have reached economic thresholds. Infestations in the field can be just a few aphids to a thousand or more aphids per plant.

Infestations were found Aug. 1 in sorghum silage trials near Bushland, and there was a report of aphids in an Ochiltree County field, he says.

“We need to make sure producers are out checking their fields, scouting for the sugarcane aphid and are prepared for when insecticide applications are warranted.”

TREATMENT THRESHOLDS

Bynum says AgriLife Extension entomologists have advised the threshold for the High Plains is to treat when:

– 20 percent of plants in the pre-boot stage have aphids.

– 20 percent of the plants in the boot stage have no more than 50 aphids.

– 30 percent in the flowering-milk.

– 30 percent infested with localized areas of heavy honeydew and established aphid colonies in soft dough and dough stages.

– At black layer, when heavy honeydew and established aphid colonies are present. Treat only to prevent harvest problems.

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Bynum says field trials have shown only two chemicals, Transform and Silvanto, provide good control of the aphid.

Other insecticide products that might be recommended for control have not proven to be effective in studies across Texas, he says.

“Producers can control the sugarcane aphid if they stay on top of the situation and make timely applications.”

For the most up-to-date news, sightings, recommendations on sampling and control, go to http://txscan.blogspot.com.