DIVERSITY AND DISTRIBUTION OF DRAGONFLY (ODONATA : INSECTA) IN THE KERIAN RIVER BASIN, KEDAH - PERAK, MALAYSIA

Odonata Larvae werw sampled from 16 tributaries of Kerian River in the Kerian River Basin (KRB) using a kick sampling method from September 1998 until May 1999 encompassing both rainy and dry season. The distribution of odonate genera was significantly different (F15,16 = 3.99) in the dry season and wet season (F15,16 = 4.70) at p = 0.05 in all rivers but no differences in distribution was detected between the rainy and dry seasons. Platycnemididae and Libllulidae were the two most dominant families together with other families Gomphidae, Coenagrionidae, Macromiidae, Chlorocyphidae, Calopterygidae, Aeshnidae and Eupheidae. Several common spesies, Platycnemis annulata, Brachythemis contaminate, Macromia gerstaeceri, Paragomphus henryii, Orthetrum brunneum, Rhinocypha quadrimaculata and Copera marginipes were identified. The calculated values of biological indices (H’, D, E, R1 and R2) showed that the dragonfly fauna in this river basin was slightly poor. Varied physico-chemical parameters of the river possibly as a result of human activities in surrounding areas were found to influence the distribution of the dragonfly larvae in the KRB. There were strong correlation between generic diversity and dissolved oxygen (r = 0.685), ferrum (r = 0.592) and pH (r = 0.583) in the rainy season. The current velocity (r = 0.37), light penetration (r = 0.36) and deph (r = 0.34) of rivers influenced the diversity the dry