DIVERSITY OF BOMBUS SPECIES (APIDAE: HYMENOPTERA) AND UTILIZATION OF FOOD RESOURCES IN NORTHERN PAKISTAN

Abstract

In agricultural habitat 10 bumblebee species were recorded. Of which 68.62% bumblebees were dominated by five species viz., B. asiaticus, B. melanurus, B. rufofasciatus, B. semenovianus and B. tunicatus. B. asiaticusatus, B. semenovianus, B. rufofasciatus, B. melanurus, B. avinoviellus, B. kashmirensis, B. subtypicus, B. haemorrhoidalis and B. himalayanus were encountered abundantly. However, in non- agricultural habitat 13 bumblebee species were recorded and more than 50% bumblebees were dominated by four species viz., B. asiaticus, B. avinoviellus, B. biroi and B. haemorrhoidalis. Significant variations were observed in the species richness of non- agricultural habitat but none in case of abundance at habitat level. However, same was true in case of non-cropped area as compared to cropped area in agricultural habitat which reflected the importance of non-cropped area as a refuge area for the development of bumblebee colonies which ultimately play a vital role in the pollination of crops, increasing their quality and quantity. Trifolium alexandrinum. Medicago sativa and Solanum tuberosum were the important only plant species which were visited by all bumblebee species in the cropped area. Cana indica, Centaurea cyanus, Cirsium sp., Dahlia x hybrid, Delphinium brunonianum, Geranium spp., Lonicera periclymenum, Prunella vulgaris, Ranunculus sp., Rosa spp., Rosa webbiana and Stachys spp were recorded in non cropped area. Similarly, the Impatiens spp. attracted significantly maximum bumblebees followed by Centaurea cyanus, Ranunculus sp., Artemisia dracunculus and Tamarix gaelic in non agricultural habitat. Forage species separated in to two conspicuous groups depending upon their utilization by bumblebees as a short and long- tongued bumblebees. Long- tongued bumblebees (B. haemorrhoidalis, B. asiaticus and B. melanuorus) were only attracted to Ranunculus sp., Raphanus raphanistrum, Centaurea cyanus, Prunella vulgaris, Cana indica, Stachys spp., Cirsium sp., Trifolium pretense, Delphinium brunonianum and Lonicera periclymenum. However, strong winds hindered the foraging activities of B. avinoviellus and B. biroi especially at Naltar.