First observations on the breeding ecology of invasive Dryocoetes himalayensis Strohmeyer, 1908 (Coleoptera: Curculionidae: Scolytinae) in its introduced range in Europe - Short communication

Abstract

The invasive bark beetle species Dryocoetes himalayensis Strohmeyer, 1908, originated from Himalayan regions, arrived in Europe in the 1970s, and is now considered to be established in several European countries (Czech Republic, France and Switzerland). This species is reported to develop in walnut (Juglans regia Linnaeus) and pear (Pyrus lanata D. Don) in the region of its origin; however, to date, there has been no information regarding its host trees and breeding ecology in its introduced range. The present paper reports the development of D. himalayensis in declining black walnut trees (Juglans nigra Linnaeus) in a floodplain forest of southern Moravia (Czech Republic). The galleries were associated with basal parts of trunks of various diameters (7-45 cm) and were accompanied by dark necrotic areas and noticeable outflow of black fluid from beetle entrance holes. Further studies on the bionomics of this species are necessary to clarify its potential status as a pest of walnut trees.