Harmfulness of invasive species gall mites (Acariformes: Eriophyidae) ‒ phyllophages Juglans Regia L., in urbocenoses of Dnipro sity

Abstract

For the first time, a detailed analysis of Juglans regia L. leaf damages caused by two species of invasive gall mites ‒ Aceria erinea (Nalepa, 1891) and A. tristriata (Nalepa, 1890), in green plantings of Dnipro had done. The research was carried out in different types of urban plantations (ravine, island area, parks, squares, hospital plots and residential areas) where 75 model trees J. regia grow. The overall level of damage to walnut leaves by gall mites in the urbocenoses of the Dnipro is 42.8 %. No mites were found in the Tunel’na gully. The level of harmfulness is dominated by the mite A. tristriata. The degree of J. regia leaves colonization by A. tristriata is 27.3 %, which is almost twice as high as that of A. erinea (15.5 %). In experimental plots where the mite A. tristriata is particularly harmful, J. regia trees are more than 50 years old and grow in linear planting under the canopy of the embankment or retaining wall in sufficient moisture condition. The average population density of J. regia leaves by A. erinea mite is from 1 to 6.2 galls per simple leaf (maximum ‒ 20); A. tristriata ‒ from 19.1 to 144.2 (1411), respectively. The study is planned to continue to identify a complex of invasive insects ‒ J. regia phyllophages.