Diversity of pollinating insects visiting litchi flowers (Litchi chinensis Sonn.) and path analysis of environmental factors influencing foraging behaviour of four honeybee species
D P Abrol
Honeybee species Apis dorsata F; A. mellifera L; A. cerana F. and A. florea F. were the most important and efficient pollinators of litchi flowers (Litchi chinensis Sonn.). They constituted more than 65% of the total pollinating insects. The ecological threshold for commencement and cessation of flight activity of each honeybee species varied from one another. In general, 15.5 -18.5˚C temperature, 600 -1700 lx light intensity, and 9 -20 mW/cm2 solar radiation appeared to be the minimum ecological conditions for commencement of flight activity in Apis species. Cessation of activities in all the honeybee species was controlled mainly by decline in values of light intensity and solar radiation irrespective of other factors. Between commencement and cessation, the foraging activity of all honeybee species followed the same general pattern as temperature, light intensity, solar radiation, nectar sugar concentration and inversely with relative humidity. Path analysis revealed that all honeybee species differed in their responses to temperature, light intensity and solar radiation, the three most important factors in foraging behavior.