The family Hepialidae Stephens, 1828, commonly known as swift moths or ghost moths, represents the most diverse family among the primitive Lepidoptera. With 725 described species (Grehan et al. 2023; Mielke et al. 2025), it is the principal family within the infraorder Exoporia and is the sister group to the Heteroneura, together encompassing over 90% of all extant butterfly and moth species (Regier et al. 2015). Globally, the larvae of most Hepialidae species are subterranean, feeding in, or on, the roots of woody or herbaceous plants, or consuming fallen foliage. Another major feeding mode involves boring into the stems and branches of trees and shrubs, where larvae feed on callus regrowth at the stem surface, or in some species, on soft woody tissues. A smaller minority of species feed on plant detritus throughout development (Grehan et al. 2023).

Hepialidae are distributed across all major landmasses worldwide except for Antarctica, and regional absences in Madagascar, the Caribbean islands, and tropical West Africa (Nielsen et al. 2000; Grehan et al. 2023). Eight genera comprising a total of 21 species are currently recorded from northern Eurasia. Most species in this group are endemic or represented in the region between Europe and the Caspian Sea (Grehan and Knyazev 2019). Their southern distributional boundary is the Mediterranean Basin, and eastwards through Jordan, Türkiye, Georgia, and northern Iran. Hepialidae previously known from Georgia are the regionally endemic or/and relic species Zenophassus schamyl (Christoph, 1888), Triodia laetus (Staudinger, 1877), and T. mlokossevitschi (Romanoff, 1884), along with the more broadly distributed European species Korscheltellus lupulinus (Linnaeus, 1758) (Grehan and Knyazev 2019). While the natural history of T. laetus and T. mlokossevitschi remains poorly understood, the specific status of the latter is uncertain, as the type specimen has not yet been dissected and described in accordance with the modern standards.

The early contributions of Romanoff (1884) and Christoph (1889), and the more recent study by Knyazev (2025) notwithstanding, the Hepialidae fauna of the Caucasus Mountains region comprising Georgia, Russia, northeastern Türkiye, Armenia, and Azerbaijan, has received limited taxonomic attention. Although the biology of the endemic Triodia species is poorly known, Z. schamyl has been studied in detail because of its status as a pest of grapevine (Slatshevskij 1929; Milyanovskii and Mitrofanov 1952).

Georgia, together with other countries bordering or overlapping the Caucasus Mountains, occupies a potentially significant boundary for the Hepialidae. The western Eurasian genera, Gazoryctra Hübner, 1821, Hepialus Fabricius, 1775, Pharmacis Hübner, 1820, Phymatopus Wallengren, 1869 have previously published distribution ranges north of the Caucasus while Korscheltellus Börner, 1920 has a southern distributional limit in Georgia. Only Triodia has a range extending well south of the Caucasus, reaching southern Israel and Jordan, however, as with T. mlokossevitschi, the taxonomic status of T. froitzhami from Israel and Jordan is also uncertain as the type has not been dissected and there are no clear external diagnostic differences.

We are grateful to the administration of the Simon Janashia Museum of Georgia for granting permission to study their Hepialidae collection. Armen Seropian (Tbilisi, Georgia) kindly reviewed the initial draft and provided valuable suggestions. Thanks to anonymous reviewers for the valuable comments and suggestions.