Molecular identification and genetic variation of urban tree-associated populations of Coptotermes gestroi (Blattodea: Rhinotermitidae) on Penang Island, Malaysia

Abstract

Abstract Background Coptotermes gestroi is one of the most destructive subterranean termite species in Southeast Asia, causing structural damage in urban areas such as Penang Island, Malaysia. This study aimed to confirm the species identity of urban tree-associated infestations and to determine whether populations from different locations on Penang Island exhibit genetic differentiation. Methods Termites were collected from three locations across Penang Island: Teluk Bahang, Queensbay, and Universiti Sains Malaysia (USM). They were identified morphologically using soldier caste features. Molecular identification was performed using the mitochondrial cytochrome oxidase I ( COX1 ) gene. Results All specimens were confirmed as C. gestroi morphologically and molecularly. Five haplotypes were identified among 23 samples based on their COX1 sequences, showing moderate haplotype diversity (Hd = 0.763) but low nucleotide diversity (Pi = 0.00526). Phylogenetic analysis indicated high similarity among sequences, with no clear clustering by location. Pairwise Fst values suggested limited differentiation between Queensbay and USM (0.1919), as well as between USM and Teluk Bahang (0.1993). In contrast, Queensbay and Teluk Bahang shared haplotypes. Conclusion All samples from three sites (three populations) in Penang Island were identified as C. gestroi using morphology and COX1 sequences. The populations of C. gestroi across Penang Island were largely similar.