DIVERSITY OF STINGLESS BEES, Tetragonula sp. (HYMENOPTERA: APIDAE) IN TAMIL NADU, INDIA

The present study was conducted to find the diversity of stingless bees (Tetragonula sp.) in Coimbatore, Madurai, Dindigul, and Trichy districts in Tamil Nadu, India. Adult worker bees were collected from feral stingless bee colonies from 16 locations, four from each district. The collected stingless bees were preserved in 70% alcohol (ethanol) and examined under a Leica stereo zoom microscope. Seventeen morphometric key characteristics were measured to know the diversity of stingless bees. The results revealed that two species of stingless bees, Tetragonula iridipennis and T. laeviceps were prevalent in the four selected districts of Tamil Nadu. Four vital morphometric characters of the worker bees namely the head width, the forewing length, the hind tibial length, and the whole body length helped to distinguish the two Tetragonula sp. Among all the locations, the bees collected from L1- Insectary, TNAU, Coimbatore had much higher values of the above four morphometric characters (1.67mm ± 0.04, 3.69mm ± 0.02, 1.53mm ± 0.01 and 3.98mm ± 0.14 respectively) and were identified to be T. laeviceps based on these key morphometric characters. The bees from rest of the 15 locations which had the morphometric values 1.59 to 1.61 mm, 3.20 to 3.41mm, 1.34 to 1.43mm and 3.51 to 3.65mm respectively were categorized as T. iridipennis.