Plant Bugs in the Delta

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With an abundance of tarnished plant bug devastation from the 2007 season in the rear-view mirror, entomologists and Extension experts across the Mid-South are bracing for another invasion this year. Between prime weather conditions and the almost inexhaustible availability of nearby host crops, the message to growers is clear: be prepared for another onslaught.

Last year’s plant bug statistics from Mississippi State’s Entomology and Plant Pathology Department paint a grim picture. Although plant bugs accounted for large losses Beltwide, Mid-South growers bore the brunt of the pest’s impact. Arkansas growers lost 44,825 bales, with per-acre control costs of up to $38 in the Delta region. Louisiana witnessed similar losses, spending up to $30.92 per acre statewide. Growers in just the Delta region of Mississippi spent a staggering $67.50 per acre and lost just shy of 20,000 bales to plant-bug damage.

Prime Conditions

In the face of such grim numbers, growers and consultants in the Mid-South are concerned about what the pests might do for an encore performance this year.

“It’s always hard to predict what insects are going to do, but typically we do have more plant bugs in a wet spring and that is exactly what we’ve been experiencing this year,” says Dr. Angus Catchot, Mississippi Extension entomologist.

The spring rains allow for natural host plants to flourish, which in turn provides ample breeding grounds for plant bugs. Catchot said he had no trouble finding plenty of the pests in mid to late May, a scenario that played out in much the same way last year. And, he says, “We’re expecting more of the same this year.”

Consultants across the Mid-South did glean some valuable treatment information during last season’s infestation, though. While there is no cure-all for the plant bug dilemma, entomologists seem to agree that reducing the number of days between treatments is one of the best lines of defense.

Lessons Learned the Hard Way

“The only way you can really deal with them is to shorten up the intervals between sprays. Our strategy has been to break the life cycle, and in order to do that you really have to do about three applications about five days apart,” says Mark Polk, a private consultant in Indianola, MS.

While options are limited for preemptive treatment, Polk urges his clients to destroy host plants around cotton fields. But of course, not all of the surrounding host plants are so expendable.

The increased amount of corn and grain acreage in the Mid-South provide additional attractive hosts for the plant bug, and as those crops dry down and become less inhabitable in mid to late season, the pests will migrate – only a few yards in some cases – into the cotton fields. The end result in 2007 was as obvious as it was painful for growers.

“We did some spraying over into the adjacent grains. We’d dressed up around corn, or milo, or soybeans and try to overlap and have sort of a buffer zone there. None of the grains were being treated with insecticides and that’s where a lot of the build up took place,” says Polk, adding that he treated surrounding crops predominately with dimethoate.

He’s not alone in advising growers to create a buffer zone in between the two crops if they are indeed planted side by side in order to minimize damage. “You talk about lessons learned last season, and one of the things we’ll be doing is scouting those interfaces a lot more closely. We may not be treating the whole field but just those borders next to the corn fields in order to save us a whole-field treatment later in the year,” Catchot says.

Caption:

Cotton adjacent to corn was a common sight in ‘07.

Caption photo:

Dr. Angus Catchot

Barnes is the senior editor for Cotton Grower magazine. In addition to writing for the magazine, he assists in online content production and in event production. He joined the Cotton Grower staff in May 2008.

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