LSU AgCenter entomologist James Villegas is investigating insect management approaches in field corn in central Louisiana and management strategies for sugarcane aphids and the headworm complex in grain sorghum.

Field corn faces several threats from insects, Villegas said. Insecticide seed treatments and caterpillar-resistant corn hybrids that express Bacillus thuringiensis (Bt) proteins are effective at controlling lepidopteran pests. In a continuing study, Villegas and his team are assessing registered and new insecticidal seed treatments against early season pests, such as cutworms, wireworms, seed corn maggots and sugarcane beetles.

“The idea is to look at whether seed treatments are necessary for corn, and for the past couple of years, we have seen an increase of wireworm infestations and sugarcane beetle as well,” Villegas said. “It used to be that we didn’t see the value of seed treatments, but in those instances, that is really where seed treatments could have helped very well.”

Villegas will also evaluate Bt corn hybrids that are pyramided, which means they combine two or more Bt traits that combat the same pest and compare the performance with non-Bt corn

“We have seen really good non-Bt corn that are yielding pretty similar to Bt hybrids, and talking to our extension agents, some producers in the northeast are actually planting a lot more non-Bt corn,” Villegas said. “Right now, the economic side is a little hard. When you’re planting, when you put more technology in the seed, the more expensive seeds are.”

Grain sorghum producers have regularly called Villegas with problems related to sugarcane aphids and seven lepidopteran species, including the fall armyworm, sorghum webworm and corn earworm.

Products in the marketplace, such as Sivanto and Transform, remain effective against sugarcane aphids, Villegas said, and products containing chlorantraniliprole still work against the headworm complex pests. This year Villegas has concentrated on reproducing conditions in fields to study these pests.

Villegas advises grain sorghum producers to consider seed treatments.

“For sugarcane aphids, seed treatments are necessary if you have historically high sugarcane aphids,” he said.

+

Corn earworm. Photo by James Villegas

Corn wireworm. Photo by James Villegas