Back in the 1970s, Fram oil filters ran a series of TV commercials touting how a little prevention, in the form of a regular oil change and oil filter, helped ward off costly engine repairs.
The take-home message: “You can pay me now or pay me later.”
That old advertisement came to mind during a recent video meeting with the University of Arkansas’ Extension entomology team of Gus Lorenz, Nick Bateman and Ben Thrash along with graduate students Chase Floyd and Trevor Newkirk.
During the past two years, the entomologists have documented a decrease in rice stink bug control using pyrethroids. They aren’t labeling it as true resistance, but they nevertheless say the insecticides aren’t providing the same level of control they once did.
If growers and consultants don’t take a few steps now to prevent resistance from occurring, they may end up losing the economical insecticides. Those prevention steps — in the form of integrated pest management — include scouting, following thresholds and only treating when they are met or exceeded, and rotating effective modes of action. The same holds true for any pesticide.
The University of Arkansas entomologists attribute part of the problem to the practice of throwing a pyrethroid in with a fungicide during the boot spray timing. Growers may view it as cheap insurance, since they’re already paying for the plane to put out the fungicide and pyrethroids only cost a couple dollars an acre.
The problem is stink bugs typically don’t move into rice fields until the plants begin heading — a full two weeks after the fungicide treatment. Until then, they hang out on grassy weeds along the field edges, so putting out an insecticide is a waste of money.
Pyrethroids have a short residual of only a few days. They’re gone by the time stink bugs begin to move in, but the application still exposes any bugs in the area to pyrethroids, increasing selection pressure and weeding out susceptible individuals.
By the time you get to late-planted fields, where stink bugs tend to concentrate because of limited food in the area, pyrethroids may have lost their punch.
Joe the Mechanic in the ads missed his calling in entomology, but his famous words still apply to stink bug management. “You can pay me now or pay me later.”