Stinkbug numbers are exploding in Arkansas rice fields, Gus Lorenz, Extension entomologist for the University of Arkansas Division of Agriculture, said Monday.
“We strongly encourage rice growers and consultants to check fields right now for stink bugs and realize how their numbers can increase in a short time,” he said.
For more, see Arkansas rice stink bug alert .
Growers base their insect treatments on population samples obtained in sweeps – in which a grower will sweep the crop with a fine-meshed net in a set pattern to see how many insects wind up in the net.
In a test begun last week in a Lonoke County rice field, the stinkbug population went from an estimated 15 stink bugs per 10 net sweeps to more than 100 stink bugs per 10 sweeps in just three days.
“In fact, many of the untreated checks were running over 200 stink bugs per 10 sweeps,” Lorenz said.
Even treated fields are still seeing high stink bug numbers after an insecticide application.
“Stink bugs are very mobile and more distances of greater than a mile in just as day or two. They are strongly attracted to fields as they begin to head, so premature spraying won’t do you any good.”
Even in research treatments, in most cases the numbers were still 20-30 rice stink bugs per 10 sweeps.
“This isn’t due to a lack of control, but more of a situation of overwhelming numbers moving into the field.”
Lorenz encouraged growers to wait until at least 50 to 75 percent of their rice crop was heading, or developing a seed head, before making the first insect treatment. “Based on the massive movement we saw in our plots, if you spray before heading you will likely end up having to treat again at 50 to 75 percent heading and then again five to seven days later.”
For more information on crop production, visit www.uaex.edu , arkansascrops.com or contact your county Extension office.