Keeping A Watchful Eye On Plant Bugs

By Jim Steadman

With some cotton fields hosting multiple stages of plant maturity thanks to a cool (and, in some cases, very wet) spring, growers are working hard to manage this crop as uniformly as possible.

They’re doing so just as plant bugs and other mid-season insect pests start moving into the fields.

“It’s crunch time,” says Scott Stewart, University of Tennessee Extension entomologist. “Mid-July until early August anywhere in the Mid-South is a really critical window. We’re going to be looking for plant bugs first, then stink bugs and bollworms as our secondary targets. The second week of bloom through the fourth or fifth week of bloom is key for plant bug, stink bug and bollworm management.”

Mid-South growers entered the planting season without Transform WG insecticide, as the product’s registration was vacated by order of the U.S. 9th Circuit Court last fall. But, new Section 18 emergency use exemptions were granted by EPA in early June to allow use of Transform in cotton across the five Mid-South states.

“Getting Transform back in the mix is really valuable to us” states Stewart. “We were going to have to rely on the two or three existing chemistries we had, and this certainly opens up more options for us.”

Growers in the Southeast are also facing more potential pressure from plant bugs and other pests, due, in part, to early season weather issues that left young cotton plants stressed after emergence.

“We really have to manage earliness,” says Dominic Reisig, North Carolina State University Extension entomologist. “We don’t have that luxury this year. Plant bugs, stink bugs and probably bollworms are likely to be bigger problems.”

Statistics show that plant bugs are on the rise in the Southeast. In North Carolina alone, plant bug treatments on average have risen from 5% of the state’s cotton acres in 2009 to nearly 50% in 2015. Despite that growth, Reisig says the state did not apply for a Section 18 for Transform, primarily because they don’t have the depth of information on plant bugs that Mid-South states have.

“Even though we’re treating more acres each year, we don’t have the number of sprays the Mid-South has,” he points out.

Scouting is the key. Both Stewart and Reisig recommend that growers scout fields every 4-7 days as soon as cotton starts squaring.

“That first two weeks of squaring is a very sensitive timeframe,” says Stewart. “If you miss a big population of plant bugs, they can do a lot of damage in a hurry.”