Bee diversity assemblage on pigeon pea, Cajanus cajan along habitat gradient.

The regional bee diversity was investigated on pigeon pea in three agroclimatic zones of Punjab state in northern India. Of the total nine species recorded, population of Megachilids, in particular, was significantly higher in all the three zones. Appraisal of diversity metrics revealed highest bee community diversity in Sub-mountain Undulating zone, followed by Central Plain zone, while least diversity was noted in Western zone, which highlighted the effect of habitat on species richness and abundance. Diurnal variations were evident with the most diverse bee communities recorded at 11:00 hr, followed by at 14:00 and 08:00 hr, with the lowest community diversity at 17:00 hr. The relative abundance of bee species was highly in favour of non-Apis species than Apis species. The results obtained can be used in the application of risk management through planned plant protection measures, study of plant-pollinator interactions along with conservation and augmentation of bee species.