Further data on the establishment of Coptodisca lucifluella (Clemens, 1860) (Lepidoptera: Heliozelidae) in Romania

Abstract

AbstractFollowing its first report in Romania in August 2022, more data regarding the walnut shield bearer Coptodisca lucifluella was collected. The leafminer moth is an invasive species of North American origin that entered Europe in 2010 (in Italy), and then spread to Hungary, Ukraine, Bulgaria and Romania. It is not an economically important pest alone but in association with other stresses affecting walnut trees, over time, it could contribute to their premature decline. In Romania, C. lucifluella was identified in 24 localities in eight counties and in Bucharest. The main host is the common walnut, Juglans regia (L.), while secondary hosts include the black walnut Juglans nigra (L.), Caucasian walnut Pterocarya fraxinifolia (Lam.) Spach and the pecan nut tree Carya illinoinensis (Wangenh & K. Koch). All walnut trees inspected in 2022 were affected by the leafminer to a greater or lesser extent. The proportion of attacked leaves per tree, evaluated in Northern Bucharest and Moara Domnească in the south of the country respectively, was 40% and 41% in August and increased to 69 and 93%, in October. Inside the mines, our team discovered a significant number of parasitoid larvae and pupae. These were kept in the laboratory until the emergence of adults which were photographed, but so far remain unidentified. The rate of parasitism was 17.4% in N. Bucharest and 31.8% in Moara Domnească.