Nesting characteristics, floral resources, and foraging activity of Trigona iridipennis Smith in Bankura district of West Bengal, India

For successful establishment of meliponiculture with Trigona iridipennis Smith, several attributes such as nesting substrates, orientations, elevation, internal characteristics of nests, floral resources, and foraging activity were studied in Bankura district of West Bengal, India. The most commonly found nesting substrate was tree trunks, especially within the cavities in tree trunks of Butea monosperma. Majority of the wild nests were oriented westward direction with an elevation of > 2–≤ 3 m from the ground level. The mean cavity size was 204.3 ± 92.45 × 159 ± 17.59 × 174.5 ± 26.13 mm3. The diversified local angiosperm flora supports the broad polylectic foraging habit of the bee species. Most of the visited plants were of tree habits and had small-sized flowers with yellow, white, and cream colours. The best represented families were Fabaceae and Asteraceae. The plants intensely utilized by the bee species were Acacia auriculiformis, Borassus flabellifer, Brassica nigra, Eucalyptus globulus, and Lannea coromandelica. In contrast to majority of multifloral honey samples, all the pollen loads were unifloral which reflects the high degree of floral fidelity behaviour of the bee species. The foraging activity of the bee species varied according to time hours, plant species, weather conditions, and seasons. It was confined to daytime from 5.00 to 18.00 h, reaching its zenith during 9.00–11.00 h and 15.00–1600 h. Maximum activity was observed in spring, followed by winter, late autumn, summer, autumn, and monsoon. Mean number of foragers without pollen load and resin load was much higher than pollen foragers and resin foragers.