06/26/07 A cereal leaf beetle update

Washington Ag June 26, 2007 In the wetter dryland wheat areas of eastern Washington the biocontrol agent for the cereal leaf beetle is doing quite the job of parasitizing the beetle and spreading beyond the insectaries where the parasitoid wasps were established. Diana Roberts of Washington State University Extension says she is pleasantly surprised. Roberts: "We are getting pretty high parasitism rates in farm fields as far as into Idaho in the Princeton area and up in the Colville area. I haven't had too many samples from Whitman County or Spokane County but the areas where we have them I mentioned they are up over 70% , sometimes up to 100% parasitism, which is very encouraging." And Roberts says when cereal leaf beetle larvae reach a 70 percent level of parasitism, the wasps are able to keep the beetle below the threshold of economic damage. The ladybird beetle is reported to be eating a lot of cereal leaf beetles this year too. In order to determine the spread of the wasps across the region Roberts wants more samples. She says you can collect a sample of 50 cereal leaf beetle larvae by clipping off the leaf they are on. Put them in a two pound yogurt or margarine container; pokes some holes in the top and put in the refrigerator. Then call Roberts at 509-477-2167 and you can work out how to get the samples to her. I'm Bob Hoff.