The discovery, published in the journal Caucasiana, is one of two first records for the South Caucasus reported in the study. The second concerns Antheraea pernyi, the Chinese oak silkmoth, a large Saturniidae species with broad wings and feathery, bipectinate antennae, whose males were collected in western Georgia’s Imereti region between 2021 and 2024. Five male specimens from Baghdati, Ilemi, Vartsikhe, and Ajameti now verify what had long been suspected but never confirmed: a locally established population of one of the world’s most historically important silk-producing moths is living and reproducing in the Caucasus wild.

Both identifications rest on a combination of morphological examination and molecular verification. The researchers used taxonomic keys to diagnose the specimens externally, then sequenced the standard Cytochrome oxidase subunit I (COI) barcode region. The Micromelalopha sieversi sequence, obtained through the Wellcome Sanger Institute’s BIOSCAN project, proved identical to sequences of the species from China, clustering under Barcode Index Number BOLD:ACQ7797. The Antheraea pernyi sequence, barcoded under the Caucasus Barcode of Life (CaBOL) project, matched material from Siberia, India, North Korea, South Korea, and China under BOLD:ABY5349. In both cases, the molecular evidence left no ambiguity about what the moths were or where their lineages originated.

The ecological significance of these records differs sharply between the two species. Micromelalopha is a genus of roughly 25 species concentrated in East Asia, distributed across China, Japan, Korea, Russia’s Primorsky Krai, and parts of South and Southeast Asia. Until this study, no member of the genus had ever been recorded outside its native range, making the Georgian population a genuinely novel biogeographic event. In China, M. sieversi is an economically important defoliator of Populus species, producing three to four generations annually in the northeast and up to five to seven generations in warmer central and southern regions. So far, no substantial harm to Georgia’s native poplars has been documented, but the potential for the moth to become a forest pest in its new environment remains an open question.

Antheraea pernyi tells a different story, one written by human hands more than a century ago. Native to China, where it was domesticated for silk production, the species was deliberately introduced to France in the nineteenth century after an epidemic devastated the domesticated silkworm Bombyx mori in 1855. It subsequently reached Spain, first in the northern provinces of Navarra and Guipúzcoa in 1875, then Barcelona and Castellón de la Plana, and by the end of the century had colonized the Balearic Islands. Today its European distribution is limited to Mallorca, Menorca, and the province of Barcelona. The Georgian population, the authors suggest, most likely traces back to Soviet-era silk farming initiatives of the 1930s, when A. pernyi was probably introduced to the South Caucasus for the same economic reasons, with individuals escaping from silk production facilities and establishing themselves in Imereti’s oak-dominated landscapes.

The larvae of A. pernyi feed on Quercus species, and Georgia’s forests are rich in native oaks, which raises obvious concerns about future interactions. As with M. sieversi and the poplars, however, no substantial damage to local Quercus species has yet been documented. The distinction between mere presence and demonstrable harm is central to invasion biology, and the study is careful to frame both moths as established non-native species rather than confirmed invasive ones. A non-native species is simply any organism found outside its natural range, typically through human activity; an invasive species is the subset of those that establish themselves and cause ecological or economic damage. Whether either moth crosses that threshold depends on factors that monitoring programs have yet to assess.

Georgia’s Black Sea coast and humid western lowlands have long proved hospitable to introduced invertebrates, and the country’s history with alien moths stretches back more than 160 years. The earliest documented case is Samia cynthia, the cynthia silkmoth of East Asia, intentionally introduced to northwestern Georgia around 1860 for silk production; it established a lasting population in western Georgia that persists today. In 1976, the fall webworm Hyphantria cunea, a North American species, arrived accidentally, most likely in infested wood transported from Ukraine, and rapidly inflicted substantial harm on native flora. More recently, the box tree moth Cydalima perspectalis was first recorded in Georgia in 2014, and its voracious larvae now pose a serious threat to Buxus colchica, the endangered Colchic boxwood listed on the Georgian Red List.

The threat is not confined to Lepidoptera or to land. The brown marmorated stink bug Halyomorpha halys established itself in Georgia in 2015 and has since become a major agricultural pest. In the Black Sea, the Asian rapa whelk Rapana venosa, first recorded in 1946 and probably transported in ship ballast water, fouling, or oyster transports, now menaces local mollusc fauna. The ctenophore Mnemiopsis leidyi, introduced in the late 1980s, preyed on zooplankton, fish eggs, and larvae so relentlessly that several fish stocks collapsed; the subsequent arrival of its natural predator Beroe ovata in the 1990s partially restored ecological balance, a rare example of a biological control dynamic unfolding naturally in an invaded sea.

Perhaps the study’s most consequential contribution is its first comprehensive list of non-native animal species recorded in Georgia, compiled from published literature, the Georgian Biodiversity Database, and Research Grade observations on iNaturalist. The list contains 134 species, spanning mammals such as the sika deer and raccoon dog, dozens of alien fish in Georgian rivers and the Black Sea, more than sixty beetle species, and a freshwater jellyfish, Crpedacusta sowerbii, documented from a single observation. The authors emphasize that the list is not exhaustive and will require continuous updating as new data emerge, but it provides the first unified baseline for a country whose invasion record had never been systematically assembled.

A striking pattern runs through the terrestrial invasions: geography. The climate and ecological conditions of the South Caucasus, particularly Georgia, appear highly favourable for the establishment of many East Asian species, from the stink bug to the box tree moth to the two newly recorded moths. This convergence presents substantial risks to native biodiversity, agriculture, and forest ecosystems, and it underscores the study’s central call for systematic monitoring, early detection, and regional collaboration across the Caucasus. Eight male moths, drawn to light in Tbilisi and Imereti, have revealed how much remains undocumented in one of the world’s biodiversity hotspots, and how quickly the unwanted guests can arrive before anyone notices they have settled in.

Subject of Research: First records of two established non-native moth species in the Caucasus and a comprehensive list of Georgia's non-native animal fauna

Article Title: Unwanted guests: The first records of two established non-native moth species in the Caucasus, with notes on non-native fauna of Georgia

Article References: Japaridze, L.-G., & Seropian, A. (2025). Unwanted guests: The first records of two established non-native moth species in the Caucasus, with notes on non-native fauna of Georgia. Caucasiana, 4, 137-151. https://doi.org/10.3897/caucasiana.4.e168433

Image Credits: AI Generated

DOI: 10.3897/caucasiana.4.e168433

Keywords: Micromelalopha sieversi, Antheraea pernyi, non-native species, biological invasions, Georgia, Caucasus, Lepidoptera, DNA barcoding, silk production, invasive species, Notodontidae, Saturniidae