Assessment of Virulence in the Wheat Curl Mite, Aceria tosichella Keifer, to Wheat Genes for Mite and Virus Resistance in the North Central United States

Wheat curl mite Aceria tosichella Keifer (WCM) is a chronic arthropod pest of wheat in the United States and Canada of major economic importance. The mite transmits Wheat Streak Mosaic virus (WSMV), the most significant wheat virus in North America, as well as Triticum mosaic virus (TriMV) and High plain mosaic virus (HPV). Plants infested with viruliferous mites appear yellow and stunted. WSMV enhances mite population increase, resulting in the increased spread of WSMV. Thirteen mite samples were collected in 2014 in high wheat yield counties in Kansas, Missouri, Nebraska, North Dakota and South Dakota to assess mite virulence to plants with the Cmc2, Cmc3, and Cmc4 mite resistance genes and plants with Cmc4 and the Wsm2 WSMV resistance gene. To date, what we found are, there are statistically significant differences between the mean scores of the mite population. Mites from Saline and Finney counties in Kansas placed on plants with Cmc4 or Cmc4 + Wsm2 produced significantly smaller populations than plant lacking resistance genes.