Many questions remain unanswered about a new pest that has been found in rice in Louisiana called the panicle rice mite. But work is ongoing to learn more about it.

This is what officials with the LSU AgCenter, the U.S. Department of Agriculture and the Louisiana Department of Agriculture and Forestry told more than 50 county agents and crop consultants gathered in a Vermilion Parish rice field on Sept. 19.

The meeting gave the group a chance to learn how to identify the mite, said Johnny Saichuk, LSU AgCenter rice specialist. The field was the first commercial field in Louisiana with a confirmed infestation of the mite.

The panicle rice mite has been found at the LSU AgCenter’s Rice Research Station in Crowley, La., as well as research facilities in Texas, Arkansas and Puerto Rico, and a commercial field in Texas. Experts are saying the locations where the mite has been found so far do not mean it originated at these research facilities. Rather, the initial intensive sampling was conducted at these sites.

“Right now we’re just putting pieces of the puzzle together,” Saichuk said. “It’s not a disaster, but it’s something to take seriously.”

Bill Spitzer of the USDA said farmers should be washing down their combines before moving from field to field to remove mites from the equipment.

He said the USDA will be surveying rice fields to see if the mite can be found at other locations. Under the current regulations, a field where the mite is found is placed under quarantine. That means the crop must be segregated, and the field must remain fallow for three months. But Spitzer said the quarantine could be lifted if the mite is found widespread in rice-growing areas.

To prevent possible carry-over into the 2008 crop, Saichuk said plowing up rice stubble would be good, but burning the remaining plant matter would be the best method. Desiccants such as sodium chlorate also could be used, he said.

“Do your best to get rid of the stubble,” Saichuk advised.

Natalie Hummel, LSU AgCenter rice extension entomologist, said various methods are being studied to determine how the pest can be eliminated from rice seed. She said it’s possible that the drying process kills the mite because it requires high humidity levels to thrive.

She said an extensive survey will be done in the 2008 crop to determine if the mite is still in Louisiana fields.

“It seems unlikely that this may be the first year they were introduced into Louisiana,” she said.

The mites feed on the rice plant’s developing panicles and the sheath, Hummel said. The mites are found in plants that appear to have fungal diseases such as sheath rot and panicle blight.

Don Groth, LSU AgCenter pathologist, said many of the problems in past years that could not be explained may have been due to the mite. But the mite was not found probably because it is so small that a 30-power microscope is required to see it.

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