Flight patterns of Russian wheat aphid, Diuraphis noxia (Kurdj.) during its expansion to Central Europe (Hom., Aphididae)

Flight patterns of migrant alate Russian wheat aphids (= RWA), Diuraphis no xia (Kurdj.) during its expansion from the south-east to Central Europe wer e determined. Samples were taken by Rothamsted-type suction air traps in Hu ngary (one location, 1990-1997) and in the Czech Republic (5 locations, 199 4-1998), The results document a progressive expansion of RWA, and populatio n variation in the individual years and periods of the season. A comparison of the evidence on RWA in the individual years since its detection in Hung ary and in the Czech Republic supports the presumption on the occurrence of an expansion route from the south-east (Turkey) to Central Europe. This ex pansion is classified as an adventive route of the over-all expansion that has covered the whole West-Mediterranean (South Europe, North Africa).