The time is right for chinch bugs in the Delta: corn is still small and vulnerable to the pest and fields are too wet to drive a spray rig across.
“Chinch bugs are having a party in my corn right now,” says L.D. Vaughn, a farmer outside Searcy, Ark. “But they should enjoy it while they can because we're going to get them. As soon as it dries up some, we're going to be spraying.”
William Johnson, Arkansas Extension corn specialist, says the scenario Vaughn describes is being played out across the state. “I'm getting calls from all over on chinch bugs. If corn was about twice the size it is now, it could just outgrow the bugs. But if corn is two to three leaves and isn't sprayed, the bugs will often overwhelm it.”
The life cycle of the tiny black insect includes finding a mate and moving into a corn plant. The problem isn't with the paired bugs, it's with the offspring they produce. After mating, some 200 offspring appear about five to seven days later. That multitude of bugs then sucks the sap out of the plant.
What happens, in effect, is the plant becomes drought-stressed because the chinch bugs overwhelm its plumbing system. After chinch bugs get into corn plants heavily, the plants begin to keel over.
Vaughn's cornfields are salvageable, says Johnson, but they need to be sprayed soon.
Why not go with an aerial application? “He can't use an airplane because putting out 10 gallons of liquid is pointless. The liquid won't get down to where the bugs are. Chinch bugs are at the first shoot, right beneath the soil surface. The best way to get to them is to use a pyrethroid and direct spray it at the base,” says Johnson.
The problem is a lot of the rigs outside cotton country aren't equipped for that. So the other option is to use a ground rig to apply at least 20 gallons of liquid with a surfactant to get the product to where the bugs are hiding. However the spraying is done, with the products now available, the plants — and hopefully the chinch bugs — will get a drenching of chemicals.
“Right now, we're left with few options because of how rainy it's been. The fields are too wet to drive across. At the earliest, it'll probably be the end of this week (May 13) or early next before a rig can get into the field,” says Johnson.
Johnson says chinch bugs are being seen from around Newport, Ark., all the way down to the Louisiana border. Anecdotally, corn farmers claim the problem is a lot worse this year than last. “And, believe me, last year was a bad chinch bug year itself,” says Vaughn.
Why are farmers seeing more stinkbugs and chinch bugs now?
“There's a lot of disagreement on that. Some folks point toward Bt crops and boll weevil eradication as the reason — with less spraying, we're no longer getting the peripheral pests. That's disputed by a lot of research people, but the timeline is such that growers don't seem to be buying into the denials,” says Johnson.
Whatever the causes, over the last two years, insect pests have hit Delta fields hard.
How effective are the compounds available to treat chinch bugs?
“They're very effective, with good residual. But you've got to get the products to the insect. In-furrow, the best thing for chinch bugs is Counter. When using Counter, we don't recommend using a post herbicide program. If the products don't interact well, a corn crop can be damaged. Growers should be careful using Beacon, Accent, Basis Gold and Steadfast. They can be used, but probably work best in a Dual/atrazine mix.”
Growers also now have the option of planting double or triple Gaucho-treated seed (called Prescribe). That appears to keep chinch bug populations in check, says Johnson.
If corn plants are mature enough, chinch bugs can be left to run their course without major damage. But Vaughn's plants are too small and beginning to go south — looking down a row, one plant is wilted and the next is okay. When the bugs get this severe, if left untreated, a grower can lose a stand.
Last year, when plants were about this size and chinch bug-infested, some growers gambled and left their corn untreated. Yields in such fields were only 80 to 90 bushels. That won't happen if Vaughn can help it.
“I've got a rig scheduled to come in from Des Arc (Ark.),” says Vaughn. “Now, if we could get these fields dried down, we'd be in business.”