HISTORICAL AND CURRENT RECORDS ON THE TIGER BEETLE, Calomera angulata, FABRICIUS OF SRI LANKA

Calomera angulata Fabricus, 1798 is a tiger beetle found in the countries of the Indian subcontinent and South-East Asia. The species contributes to the species richness of the tiger beetle fauna of Sri Lanka which is amongst the top ten countries of the world for tiger beetle diversity. In the present study historical records of C. angulata were studied using publications dating from 1904 to 1989 and specimen collections at museums and research institutions. Current records were studied by conducting field investigations in 116 locations in Sri Lanka from August 2002 to November 2005, March 2008 and May 2013 to August 2015. In field studies locations and habitat types of C. angulata were noted and climatic and soil parameters of the locations were recorded. Two to five tiger beetles were collected from each location and were identified and subjected to morphological and molecular characterization. The study revealed that historically the species occupied 8 provinces of the country and were distributed in all three climatic zones. Habitat types and habitat preferences of the species were not reported in historical records. According to current records the species is only found in 4 provinces restricted to the dry and intermediate zone and is not found in the wet zone and western and southern part of the country. C. angulata mainly occupies reservoir bank habitats with reddish brown-yellow coloured soils with sandy texture and specific climatic and soil conditions. The suitability of these habitats to C. angulata may be responsible for change in distribution of the species as currently both the habitats and species are found in the dry and intermediate zones of the country. Competition by other tiger beetle species and unsuitability of previous locations due to accelerated developmental activities are suggested as strong possibilities for the distributional change of C. angulata of Sri Lanka.