Beetle abundance, diversity and species richness of Pulau Pangkor, Perak, Malaysia

Abstract

Islands have attracted great enthusiasm for biogeographers, evolutionary biologists and ecologists as they are good testing grounds for various biological hypotheses. The objective of this study was to assess the beetle diversity and abundance of Pulau Pangkor forest reserves. Beetles were collected using 12 light traps for 4 hours at night, 24 hours collection daily using 100 pitfall traps and 12 Malaise traps for a duration of six days from 15th to 21st July 2017. A total of 277 beetle specimens comprising of 116 species from 26 families were collected, where 75.21% of the collections were singletones. Shannon-Weaver Index showed a value of 3.847 whereas, Fisher alpha diversity index and Simpson Diversity index showed 72.45 and 0.948, respectively. Margalef index for abundance showed a value of 20.09, while the estimated species richness based on Chao 1 showed 347.80. The most abundant family is Bostrichidae accounting for 86 specimens from 20 different species followed by Carabidae with 57 specimens from 10 species. The Cyclosomus sp. (Family Carabidae) collected is reported to be a new species to be described later. Species accumulation curve doesn’t reach the asymptote which is generally observed in the tropics due to the high specious nature. This study shows the beetle diversity at Pulau Pangkor is unique and it requires conservation of habitats. This study can be extended to annual beetle diversity pattern to assess the hypothesis related to biomass reduction, anthropogenic disturbances and island biogeography.