Diversity, Species Richness and Foraging Behaviour of Pollinators in Cashew

Abstract

Insect visitors documented on cashew flowers during the present investigation include 40 species belonging to 13 families of three insect orders. The Hymenopterans were the major floral visitors comprising of bees, ants and wasps followed by dipterans. Among the 40 species recorded as flower visitors, only 13 are considered as pollinators of cashew, in which eight belong to Apidae and five belong to Halictidae. Among the two bee families, Apidae was the most abundant contributing 75.6% of the bee abundance. Within Apidae, the highest species abundance was recorded for Braunsapis picitarsus (20%) followed by Apis cerana indica (16.7%). Halictidae bees contributed to 24.4% of bee abundance, among which Pseudapis oxybeloides was most abundant (17.6%). Peak bee activity was recorded between 11.00 and 13.00 h for most of the bees. During 10.00–13.00 h, B. picitarsus was the most abundant (22–31%) followed by P. oxybeloides (18–25%), A. c. indica (12–15%), Ceratina sp. (8–13%) and A. florea (6–14%). Foraging rate was more for A. c. indica followed by B. picitarsus and A. florea. Lesser time was spent by A. c. indica for nectar and P. oxybeloides for pollen (i.e. 1–4 s), while longer time of 3–21, 8–16 and 5–11 s was spent by A. florea, B. picitarsus and Tetragonula sp., respectively. Bees of C. hieroglyphica, Lasioglossum sp. and Seledonia sp. spent 2–6 s per flower. Foraging rate was higher in A. c. indica and B. picitarsus, while foraging speed was lesser in A. c. indica and P. oxybeloides. Nesting sites of different bee species and the common bee flora in the study area were also recorded.