Assessment of Effectiveness among Native Bees in Enhancing Trifolium alexandrinum Seed Production

Abstract

Trifolium alexandrinum L. is a multi-cut, winter annual fodder crop in the South Punjab region of Pakistan. Being cross pollinated crop, better seed production of T. alexandrinum depends upon insect pollinators. Current study was planned to find effective native insect pollinators which play a crucial role in enhancing seed production of T. alexandrinum. The goals were achieved by recording the diversity of insect pollinators, abundance, foraging activity and most importantly pollination efficiency in a single visit in terms of reproductive success parameters (head size, florets per head, seed count/head, seed mass/head and seed mass of 1000 seeds). The pollinator's community was composed of 06 Hymenoptera, 03 Diptera and 02 Lepidoptera species. It was found that the total abundance of a solitary bee Pesudapis oxybeloides was higher followed by a honey bee, Apis mellifera and a syrphid fly, Eristalinus aeneus. Moreover, solitary bee P. oxybeloides was detected as the most efficient pollinator based on rate of visitation and pollinator efficiency in a single visit, followed by A. mellifera and A. dorsata. The seed set in open pollination (free insect visits) was 58 and 70% higher and seed weight of 1000 seeds respectively as compared to self-pollination (no insect visits). Hence, conserving these most efficient native pollinators can lead to higher seed yield of T. alexandrinum and other seed crops in South Punjab, Pakistan.