Naturalisation of the Transcaucasian and East Anatolian darkling beetle Odocnemis aurichalcea (Adams, 1817) (Coleoptera: Tenebrionidae: Helopini) in the North Caucasus

Abstract

The present state of the invasive population of Odocnemis aurichalcea (Adams, 1817) (Coleoptera: Tenebrionidae) in North Caucasus is studied. This species is widespread in Transcaucasia and has entered Nalchik and Nartkala towns (North Caucasus, Kabardino-Balkaria, Russia) possibly during urban greening where it is mentioned in these localities since at least the middle of the 20th century. Nothing was known about the status of this invasive population for 54 years. A rich population of this species was discovered in the outskirts of Nalchik in a natural beech forest in 2022. The species is naturalized in the North Caucasus, but inhabits only a very narrow, isolated range in this region. Diurnal activity, the response of adults to high temperature and humidity, habitat and trophic associations, and current distribution of the species in the North Caucasus are assessed. Taxocenes of tenebrionids from the tribe Helopini, including O. aurichalcea, were described. We establish that imagoes of the species occupy a narrower ecological niche in the invasive range under natural conditions, than in the native range, inhabiting exclusively beeches and feeding on algae of the genus Desmococcus F. Brand, 1925 (Chlorophyta: Trebouxiophyceae).