Alert and prevention of the spreading of Aegilops tauschii, a worst weed in wheat field.

Aegilops tauschii, an alien invasive species, is widely spreading in Hebei and Shanxi Prov- inces, the infested areas are expanding rapidly, threatening agriculture and food safety in China. Based on field survey, its origin, infestation were analyzed, measures to meet the urgent need for delaying the spreading of Aegilops tauschii were proposed.