Altitudinal food preference of bumblebee species (Hymenoptera: Apidae) from Indian Himalaya
Rifat Hussain Raina, Malkiat Singh Saini and ZH Khan
This paper describes the food preferences of bumblebee species available in the lower and upper reaches of North-east and North-western Indian Himalaya. These anthophilous insects are completely dependent on pollen and nectar on the high altitude flora and in turn help in their pollination. At higher reaches these insects are one of the most efficient pollinators and are responsible for the conservation of high altitude vegetation germplasm. Depending upon the altitude, different species have different host plants in the Himalayas. The overall picture reveals that there are some plants on which Bumblebees feed heavily such as Cisium arvensis, Cirsium falconeri, Carduus spp., Nepeta spp., Prunella vulgaris, Impatiens balsamina, Saussurea spp., Trifolium repens and Trifolium pratense. However, there are some other plants like, Artemisia spp., Pedicularis pectinata, Swertia spp. and Indigofera spp.which though occur in close proximity to the above mentioned plants but are seldom visited. The bumblebees are generally associated with different types of flowers (wild or cultivated) and are found foraging in various mountainous regions. The open sunny meadows are favoured by these insects in comparison to the closed deep and dense forests. The species confined to high altitudes are small in size, dull in colour and during flight produce a high buzzing sound. This small size of high altitude species is correlated with the fact that the vegetation present in these areas is in the form of small bushes having very small flowers preferring smaller insects which can easily feed and pollinate them. These species are so adapted to their specific habitats that many of species that are found here are not reported from low altitude areas and vice-versa.