Dynamics of the range of lily leaf beetle (Lilioceris lilii, Chrysomelidae, Coleoptera) indicates its invasion from Asia to Europe in the 16th–17th century

Abstract

An analysis of 415 locations of Lilioceris lilii (Scopoli, 1763), a pest of ornamental liliaceous, allowed tracing the dynamics of the species range in Eurasia from the 18th century to the present. Now the area of distribution is a continuous band across the whole continent, from Portugal to the Khabarovsk krai, but until the end of the 19th century, the range was disjunctive. It consisted of two large subranges: European and Asian. There was a gap of about 2000 km between them. The easternmost of the known European locations of the 19th century lies in Voronezh oblast, while the far west of the Asian location is in the vicinity of Omsk. In Asia, the species ranged in Siberia, the Far East, and northern China. Taking into account the Asian origin of host plants of the lily beetle, as well as the genus Lilioceris in general, it can be assumed that the European subrange is secondary, invasive. The disjunctive range could hardly be of relict origin, since L. lilii can quickly establish and develop vast territories in decades. This ability of the lily beetle is evidenced by the distribution of this invasive species in Britain, Canada, and the United States. From the literature, it is known that in 1688 the lily beetle already inhabited Western Europe, and Siberian species of lilies were first brought there in 1596. Apparently, the pest was introduced together with planting material in this time interval. By the mid-20th century, L. lilii had settled in the Volga region, the Urals, and the south of Western Siberia. Thus, the range gap virtually ceased to exist. In recent decades, the range in the European part of Russia has expanded to the north and northeast. By now, the lily leaf beetle has populated even some areas where its host plants are found only as cultivated or adventive plants.