As harvest nears, the white sugarcane aphid continues its residency in much of the Mid-South’s grain sorghum.

“This pest jumps out pretty quickly,” said Nick Seiter, University of Arkansas entomologist. “It can hit high numbers very quickly. There have been a lot of acres sprayed for it. At least half the crop has been sprayed or should have been. It’s become a major concern for milo throughout the state.”

As of August 13, the aphid had been found as far north as Randolph County in Arkansas.

“It’s still difficult to control,” said Seiter. “We are getting decent results with higher rates of Transform. Occasionally, there needs to be a retreatment. If a grower gets on normal populations quickly then usually one application is good.”

That hasn’t always been the case in Mississippi.

“There’s one thing to say: we just don’t know a lot about how to manage this insect,” said Jeff Gore, Mississippi State University entomologist, at the Aug. 13 field day at the Delta Research and Extension Center in Stoneville. “We’re learning every day, though. It’s been frustrating for us because we’re used to providing growers and consultants with answers. With this insect we haven’t been able to do that. In fact, our recommendations have sometimes changed from week to week as we learn new things about it.”

The Section 18 for Transform gave producers “the only thing that provides effective control the way we need it in Mississippi,” said Gore. “One thing we’ve begun to question is, in a lot of situations, there’s a limit of two applications of (Transform). The state has a lot of acreage that’s already been sprayed twice and needs a third before harvest.

“So, can we legally manage this insect this season? We’re trying to get a Section 18 for a third application and haven’t heard anything yet. We are fairly optimistic we’ll get that third application.”

White sugarcane aphids, making a mess in milo

That optimism was justified as, on Aug. 14, Gore and colleagues announced that a third shot of Transform had been secured for the state.  Since treatments only work for up to 14 days, “it appears that on some of the later planted grain sorghum it would not be possible to finish the season out with only two applications of Transform allowed per season.

“Just today, EPA announced an amendment to allow three applications as long as we do not exceed the seasonal use limit of 3 ounces per acre. Because we have been recommending 1 ounce rates in Mississippi, this will allow a desperately needed third application in many fields.”