Biodiversity of water beetles assembled by light trapping in Malaysia

Water beetle  plays a significant role in ecosystem dynamics  at forest, freshwater lakes, ponds, rivers, mountain and agriculture.  This paper presents  a checklist of water beetles assembled  in Peninsular Malaysia.  This study was conducted at seven different sites from August 2006 to November 2009. A total of 257 individuals were recorded at sixty one sampling sites in eight states. A total of 257  specimens, 23 species belonging to  five  family Dryopidae, Dysticidae, Elmidae, Gyrinidae and Hydrophilidae were sampled.  234 specimens remained unidentified and probably new species.  Identified species were Lacconectus species 1 and species 2, Lacconectus lividus, Lacconectus fulvescens, Canthydrus haagi,  Batrisode species 1, Sostea sp, Omicrogiton sp,  Coelostoma sp and  Porrhorrhynchus sp. The most abundance of water beetles were at Pahang (Margalef index: 2.79) followed by Negeri Sembilan (Margalef index: 2.54), Johore (Margalef index: 2.03), Perak (Margalef index: 1.95), Kedah (Margalef index: 1.88). The  most species rich was from Dysticidae family at Mt. Angsi (Evenness Index: 0.92) compared to the Mt  Panti Forest reserve (Evenness Index: 0.41), Bintang Range  (Evenness Index: 0.25) and Cameron Highland. Factors  affecting biodiversity of water beetles are discussed.