Diversity, visitation frequency, foraging behaviour and pollinating efficiency of insect pollinators visiting turnip blossoms

摘要

Turnip (Brassica rapa) is a self-incompatible crop and needs pollen vectors for cross-pollination of its flowers (Free, 1993; Sihag, 1985). Several species of pollinators visit its flowers (Sihag, 1986). However, all are not equally important. Some make a better contribution to pollination because of their more suitable attributes. These include abundance, foraging behaviour, number of loose pollen grains carried on the body, foraging rate and activity duration. An index value derived from these attributes was used to compare the efficiency of the pollinators of pigeon pea (Cajanus cajan) (Sihag and Rathi, 1994). This paper uses the same approach to study the pollinators of turnip.