Genetic variation of the giant water bug Lethocerus indicus (Lepeletier and Serville, 1825) (Hemiptera: Belostomatidae) collected from natural habitats in northeastern Thailand

The giant water bug, Lethocerus indicus (Lepeletier and Serville, 1825), is one of the most important edible insects in Thailand. This study investigated the genetic diversity of L. indicus from natural resources in northeast Thailand by using mitochondrial DNA sequences. Ninety adults of L. indicus were collected from 12 different localities by light trap and hand-net methods. Nucleotide and haplotype diversity of cytochrome c oxidase subunit 1 (CO1) sequences were relatively high. The 43 CO1 haplotypes (Li1-Li43) with 26 unique haplotypes were classified and used to generate a star-like haplotype network. The most common haplotypes were Lib and Lit shared between 19 and 15 sequences, respectively from nine different localities. A phylogenetic tree clearly separated L. indicus from the other species and closely clustered with a sibling species, L. patruelis (Stal, 1854). However, the comprehensive genetic variation of L indicus covering broad range of areas needs to be further explored.