Biodiversity and distribution of Trichoptera species along the Tapee River, Surat Thani Province, southern Thailand

The Tapee River is one of the most important rivers in southern Thailand. The river crisscrosses from Khao Luang National Park, Nakhon Si Thammarat province to Surat Thani province and flows to the Thai Gulf. To study the biodiversity and distribution of Trichoptera species along the Tapee River, insects were collected by light trapping every 3 months from April 2004−February 2005. The results show that 105 species were found in 35 genera of 15 families. The most abundant families of Trichoptera in the Tapee River were Hydropsychidae, Leptoceridae, and Ecnomidae. The more widespread Trichoptera species included Ecnomus atevalus Malicky & Chantaramongkol, Dipseudopsis knappi Schmid & Denning, D. robustior Ulmer, Aethaloptera sexpunctata (Kolenati), Amphipsyche meridiana Ulmer, Cheumatopsyche cognita (Ulmer), Macrostemum fenestratum (Albarda), Ceraclea idaia Malicky & Chaibu, Oecetis tripunctata (Fabricius), and Parasetodes respersellus (Rambur). The upper Tapee River Trichoptera species included Rhyacophila petersorum Schmid & Denning, R. tantichodoki Malicky & Chantaramongkol, Ugandatrichia kerdmuang Malicky & Chantaramongkol, Chimarra spp., Pseudoneureclipsis spp., Psychomyia spp., Cheumatopsyche charites Malicky & Chantaramongkol, Diplectrona spp., Hydropsyche spp., Hydromanicus inferior Chantaramongkol & Malicky, Goera spp., Ganonema fuscipenne (Albarda), Goerodes abruptum Banks, and Marilia spp. The lower Tapee River Trichoptera species included Ecnomus talenoi, E. paget, Polymorphanisus spp., and Oecetis bengalica. The number of Trichoptera species was higher upstream and lower downstream.