First Record and Ecological Data for the Alien Mediterranean House Gecko, Hemidactylus turcicus (Squamata: Gekkonidae), in Pyeongtaek, South Korea

The Mediterranean house gecko, Hemidactylus turcicus (Linnaeus, 1758), is a widespread alien reptile that was recently designated as an “Alert Alien Species” in South Korea. This study documents the first stable established population of H. turcicus in Pyeongtaek, South Korea, and assesses its ecological adaptation through longitudinal field surveys and fecal metagenomic analysis. From September 2024 to September 2025, 105 individuals, including juveniles and gravid females, were observed utilizing anthropogenic structures for overwintering, indicating successful demographic establishment and thermal adaptation. Molecular identification based on the mitochondrial COI gene confirmed species identity with > 97% similarity to the known sequences. Fecal metagenomic analysis revealed a predominantly insectivorous diet composed mainly of Coleoptera, Blattodea, and Hemiptera, with 62% of the families matching the local native fauna. Notably, the detection of Trichinellidae nematode DNA in fecal samples highlights a potential zoonotic risk associated with this alien population. Although the population is currently in the lag phase of invasion, its exploitation of local prey resources and artificial habitats necessitates immediate management and monitoring to prevent range expansion and reduce predation pressure on native prey species.