Listobloshki roda Psyllopsis (Homoptera, Psylloidea) [Psyllids of the genus Psyllopsis (Homoptera, Psylloidea)]

Abstract: Including the newly described Psyllopsis repens, sp. n., Psyllopsis proprius, sp. n., Psyllopsis machinosus, sp. n. and Psyllopsis securicola, sp. n. the genus Psyllgpsis Low is composed of ten species tied to species of Fraxinus. Psyllopsis mexicana Crawford, however, differs strongly from the morphological structure typical of the genus. Its nutritive plant is unknown and its placing in the genus Psyllopsis seems to be scarcely justified. Psyllopsis fraxini Lin., P. discrepans Flor, P. fraxinicola Frst. and P. proprius, sp. n. are among the common species occuring on the ash-tree and, in the European part of the palaearctic region, are more or less widely distributed from North to South. The distribution of Psyllopsis distinguenda Edwards is restricted to the British Isles. The areas of distribution of Psyllopsis machinosus, sp. n., P. securicola, sp. n~ and possibly even Ps. repens, sp. n. are in the southeast parts of the Palaearctic. With the exception of Armenia the first of these species is known from Djambul ( Kazakhstan), Kara-Kala (Turkmenia) and Pendjikent ( Tadjikistan), also, and two other species have been ascertained in Kerrnan (Iran). Among Ash-tree species Fraxinus excelsior and its forms are much in favour with all species of Psyllopsis. They attack, however, even Fraxinus oxycarpa, F. ornus and others. The occurence on Fraxinus pennsiluanica and F. americana is only accidental as the younger stages have not been found on them. The chemical structure of saps of the mentioned Ash-trees is evidently not suitable for their nutrition and therefore these trees are not attacked by them. The typical faculty of the representatives of the genus Psyllopsts is the ability to make galls. The type of deformation of the leaves is undulate and in the form of a little tube which bends down and turns rose or yellow and, after maturity of the nymph the tissue of the galls decays. The gall production is known with Psyllopsis fraxini, P. discrepans and has been presumed with P. distinguenda (Heslop-Harrison, 1942). The present author has discovered them with P. repens, sp. n. With regard to other species our present bionomical knowledge is insufficient and therefore it is not yet possible to say whether they have the same ability to create galls. It is commonly the case with the Psyllidae living on the Ash-tree that several species will occur on one tree. In Kamyshin and Askania Nova, Crimea and in the environs of Kursk have been found tree and in Jerevan four species jointly on the tree. The injury to the nutritive plant is thus increased, especially when respective species breed rapidly. The author has observed particularly strong damage to Ash-tree in Jerevan and Kamyshin. The yearly increase here was insignificant, the trees have been losing more than 30% of the assimilative area and there was the case of infection by secondary parasites and in the middle of summer (when the summer generation flies) the tops of trees are rust-coloured as a result of the decayed tissues of the galls.

Key words: new species, Psyllopsis, Psylloidea, Homoptera,