Abstract
The walnut husk fly (Rhagoletis completa Cresson, (Diptera: Tephritidae) is another invasive tephritid species recorded in Hungary. It is native to Midwestern United States and introduced to California, where it has significant economic impact in walnut production. It is one of the most serious walnut pests in California. The species was recorded in Switzerland for first time in Europe, in 1991. In 2011 walnuts infested by R. completa were found near Kôszeg (West Hungary). Early infestation may reduce the size of the nut and causing shrivelling of the kernel, further the nuts may fall earlier than normally. Already a moderate infestation can significantly reduce the walnut’s quality.