Review of Belostomatidae (Hemiptera: Heteroptera) in Thailand

Abstract

Importance of the work: This is the first research report on the taxonomy of Belostomatidae in Thailand, with extensive distribution records.
Objectives: To characterize the belostomatid fauna and provide biological information and a taxonomic key of belostomatids in Thailand.
Materials & Methods: Approximately, 500 specimens of giant water bugs were collected from natural habitats in different localities in Thailand during 1995–2020 using a light trap and an aquatic D-net. Specimens were identified to the specific taxonomic level based on morphological characteristics.
Results: Three species, representing two genera of the Belostomatidae, were found in Thailand: Diplonychus rusticus, Lethocerus indicus and L. patruelis. Members of this family were commonly found in a wide variety of aquatic habitats, such as rice paddies, vegetated ponds and slow-flowing streams. Specimens of D. rusticus were collected from peat swamps in southern Thailand. Numerous specimens of L. indicus were collected from the light trap. The intraspecific variations of specimens were observed in members of each species in Thailand. The distinguishing morphological characters for the belostomatid species in Thailand include body size and shape, number of claws and markings on the pronotum and sternum.
Main finding: This research confirmed that there are three species of Belostomatidae in Thailand, with Diplonychus rusticus and L. indicus being widely distributed throughout the country, while L. patruelis was identified from sites in northern and southern Thailand.