First record of the invasive walnut leaf miner Caloptilia roscipennella (Lepidoptera: Gracillariidae) in Kashmir, India

Abstract

Caloptilia roscipennella (Hübner, 1796) is a leaf-mining moth native to Central and Southern Europe. In this publication, we provide the first report of the occurrence of Caloptilia roscipennella in India. The identification was performed using an integrative approach, combining molecular (barcoding, COI) and morphological analysis (forewing pattern). In 2020, the larvae were initially found scraping in the silvery-white mine and later feeding in folded or rolled leaves of the common walnut Juglans regia L. In the subsequent years, the species was found only in the same places. Two generations were recorded per year (May–June and August–September) and leaf miners overwintered as adults and reappeared in the early spring. Damage ranging from 15% to 20% was observed on the leaves of J. regia. Further efforts related to C. roscipennella should concentrate on evaluating its geographic distribution and its impact on walnut trees. Several species of parasitoids were reared from infested mines, with specimens belonging to the genus Chrysocharis Förster, 1856 (Hymenoptera: Eulophidae) and Itoplectis maculator (Fabricius, 1775) (Hymenoptera: Ichneumonidae). These species provided excellent control of leaf miner larvae, and out of 10 larvae, seven were found parasitized by the parasitoids and higher numbers of specimens were found with relative higher frequencies.