Abundance and diversity of pollinator fauna of sunflower (Helianthus annuus L.)

Abstract

Insect pollinator abundance and diversity were assessed in sunflower (Helianthus annuus L.). Totally, 22 species of pollen and nectar foragers were recorded commencing from 0600 upto 1900 hrs at hourly intervals during different stages of flowering. The composition of different orders comprising of pollinator fauna were, Hymenoptera (72.73%), Diptera (9.09%) and Lepidoptera (18.18%). Among the Apis species (A. dorsata, A. cerana and A. florea), followed by non-Apis (T. iridipennis) were most abundant and they constituted 98 per cent of the total flower visitors in the variety Morden, the Shanon-Weiner index of diversity (H) computed for the pollinator fauna varied between 0.00 to 1.52 and 0.00 to 1.49 at 50 and 100 per cent flowering stage of the crop respectively. The Berger-Parker dominance index (‘d’) values ranged between 0.000 to 0.587 and 0.000 to 0.595, respectively, implying that A. dorsata was the most dominant species (0.587 & 0.595), followed by A. cerana (0.149 & 0.138) > A. florea (0.128 & 0.121) > T. iridipennis (0.091 & 0.095) at 50 and 100 per cent flowering stages, respectively.