Morphological and cytological separation ofAmphorophoraBuckton (Homoptera: Aphididae) feeding on European raspberry and blackberry (Rubusspp.)

Abstract

Aphids of the genus Amphorophora collected from European raspberry, Rubus idaeus, have a chromosome complement of 2n(♀)=18, whereas Amphorophora from R. fruticosus agg. (blackberry, brambles) have a basic chromosome complement of 2n(♀)=20. Canonical variates analysis based on eight characters measured on numerous samples of apterous virginoparae showed that Amphorophora on European Rubus can be separated morphologically into two groups consistent with the differences in host plant and karyotype, and these two groups are concluded to be separate species. The correct name for the aphid on raspberry that is a vector of European raspberry viruses is Amphorophora idaei (Börn.), and the species on blackberry is A. rubi (Kalt.). Simple biometric methods of discriminating between A. idaei and A. rubi based on pairs of variables are suggested, and their reliability is discussed. Taxonomic problems in the European and North American Rubus-feeding species of Amphorophora are considered with particular reference to their importance in applied entomology.