Pollen Sources of Stingless Bees (Hymenoptera: Meliponinae) in Nam Nao National Park, Thailand

Abstract

Stingless bees (Hymenoptera: Meliponinae) play an important ecological role as insect pollinators of many flowering plants in subtropical and tropical regions. This research aimed to investigate the species diversity and pollen sources of stingless bees in Nam Nao National Park, which covers the border between lower northern and upper northeastern Thailand, during January 2013 ??? June 2014. The sample collections of insects and plants were collected along two existing forest trails: bamboo-deciduous forest (BB/DF), and deciduous dipterocarp-oak forest (DOF). Ten stingless bee species including Homotrigona fimbriata (Smith, 1857), Lepidotrigona nitidiventris (Smith, 1857), Lepidotrigona terminata (Smith, 1878), L. ventralis (Smith, 1857), Lisotrigona cacciae (Nurse, 1907), Tetragonilla collina (Smith, 1857), T. laeviceps (Smith, 1857), T. minor (Sakagami, 1978), Tetrigona apicalis (Smith, 1857), and Te. melanoleuca (Cockerell, 1929) were found from this study. All value indices, the species diversity index (H???), the species evenness index (J???) and species richness index (D) showed that bamboo-deciduous forest have higher species diversity than the deciduous dipterocarp-oak forest. The similarity coefficient (S_S) showed similar community structure of stingless bees in both types of forest. Moreover, their pollen grains were indentified in 70 plant species from 31 families. The family Asteraceae (Compositae) was the most diverse (12 species). The main pollen source of stingless bees found in both types of vegatation was Synotis cappa (Buch.-Ham. ex D.Don) C.Jeffrey and Y.L.Chen. The highest number of bee flora was found from pollen loads of T. collina (44 species), while T. laeviceps ranked second (44 species), and L. terminata ranked third (38 species). These results suggest that the studied areas can provides food sources for stingless bees where is important for maintaining populations of them.