| New pest haunts southeastern Idaho barley growers A pest new to Idaho barley growers—the Haanchen barley mealybug—is infesting five southeastern Idaho counties:Bingham, Bonneville,Caribou, Jefferson, and Madison. Discovered by University of Idaho entomologist Juan Manuel Alvarez near Soda Springs in a commercial barley field last June, the rapid spread of the pest could be due, in part, to the fact that female mealybugs do not need males to reproduce.They have a short generation time and can lay more than 400 eggs in two weeks. Feeding by the aphid-like insect reduces the amount of chlorophyll in barley leaves,causing plants to turn yellow or brown.Alvarez,working at UI Aberdeen R&E Center labs, finds that as few as 10 mealybugs per plant can cause leaf-yellowing within a week.Heavy infestations in commercial fields eventually kill plants.The mealybug can damage the crop indirectly by injecting a sticky sap-like substance,called honeydew,which reduces grain quality and even clogs combines at harvest. Why the pest has found its way to Idaho is unknown,and no registered insecticide fights the pest.Scientists at the Aberdeen lab are currently testing insecticides to provide assistance for infested crops next year.For more information,including photographs,see http://info.ag.uidaho.edu/pdf/CIS/CIS1109.pdf.Or contact Alvarez at jalvarez@uidaho.edu. -- Amanda DeRuwe © 2003 University of Idaho, College of Agricultural and Life Sciences. |
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