First Record of Rhopalosiphum maidis (Fitch) (Homoptera: Aphididae) in Slovakia

During the autumn of 1999, an outbreak of Rhopalosiphum maidis (Fitch) was observed on barley volunteers at locality Nitra-Malanta (48° 19´ N, 18° 09´ E) in Slovakia. Barley plantation arose from dropped grain of spring barley harvested on July 20, 1999. The soil was not cultivated after the harvest. During the observation, in October, nearly 80% of tillers were in growth stage of heading and nearly 20% of tillers were in growth stage of booting. The abundance of R. maidis reached 61.13 and 67.37 individuals per main and lateral tiller respectively. R. maidis was not observed on maize fields in the vicinity of the infested barley plantation. The highest percentage of populations constituted larvae and nymphs. Alate females formed 6.7% of the R. maidis population. From 2116 aphids observed on 30 main tillers 97 (4.58%) and from 2283 aphids observed on 30 lateral tillers 153 (6.70%) were infected by entomophthoralean fungi Entomophthora planchoniana Cornu or Erynia neoaphidis Remaudičre et Hennebert