Rice farmers soon will have two more weapons in their arsenals for fighting stink bugs and rice water weevils. The U.S. Environmental Protection Agency recently approved gamma cyhalothrin for use in field, vegetable, tree and vine crops. It will be sold as Proaxis and in a higher-concentrated form called Prolex.

Farmers should be able to buy the products in early May, according to Robert Stewart, communications manager for Dow Agrosciences. He said approvals must be obtained from the different states where the chemicals will be sold.

Proaxis and Prolex will be sold by Pytech Chemicals, a joint venture between Dow AgroSciences and Cheminova.

“They're additional options for what we already have,” said Boris Castro, an LSU AgCenter entomologist. Castro said the additional insecticides will help replace such chemicals as Furadan and Icon. Furadan was removed from the market by the EPA, and Icon is no longer being made by the BASF Corp.

The new products are labeled to control adult rice water weevils, rice stink bugs, chinch bugs, grasshoppers and leafhoppers. Both are applied to the foliage of rice plants, Castro said. Like Mustang Max and Karate, they are pyrethroids that attack insects' central nervous systems, he explained.

Prolex is applied 1.28 to 2.05 fluid ounces per acre, and Proaxis is applied 3.2 to 5.12 fluid ounces per acre.

Farmers who have used Mustang Max and Karate “don't really need to learn anything new,” Castro said.

LSU AgCenter entomologist Mike Stout said the newer chemicals should be used after seeing weevils in the field or after finding signs they have been feeding on rice plants. Although the AgCenter doesn't recommend pre-emptive treatment, many farmers use that approach, he said.

“In south Louisiana, you can almost guarantee you'll have weevils in the fields,” Stout said.

Stout explained that the new product line has the same chemistry as Karate. The LSU AgCenter entomologist, who tested the new product line on rice fields at the AgCenter's Rice Research Station at Crowley, also said it proved as effective as Karate. “It's a juiced up version of Karate,” he said.

A flooded rice field attracts adult weevils that feed on the maturing plants and lay eggs in the field, and it's the larvae that hatch from the eggs that devastate the rice plants' root systems.

Despite the destruction pests can cause, Castro cautioned misuse of chemicals can cause more problems in the long run. “Eventually, if we don't use these with care, that can bring up resistance to these chemicals,” he said.

Because of those types of issues, work already is under way to develop new alternatives, Castro said, adding, “It is not a good idea just to have foliar insecticides.”

The presence of a new product line should spur competition and might lower prices, according to Castro. “The same thing happened with Mustang Max,” he said.


Bruce Schultz writes for LSU AgCenter Communications. Contact him at 337-788-8821 or bschultz@agcenter.lsu.edu.