Pollination of Brassica campestris (Cruciferae) by Andrena savignyi (Andrenidae: Hymenoptera): Female vs. Male Pollination

Waseem Akram,Asif Sajjad

doi:10.13102/sociobiology.v69i1.7300

Abstract

Female and male solitary bees usually differ in their behavioral and morphological attributes and consequently in their pollination effectiveness. The current study was carried out at the research farm of The Islamia University of Bahawalpur, Pakistan, to compare the foraging behavior and pollination efficiency of female and male Andrena savignyi Spinola, 1838 on Brassica campestris. The impact of different environmental factors (temperature, relative humidity, light intensity and wind speed) on foraging behavior was also studied. Andrena savignyi was the most abundant floral visitor of B. campestris and comprised 52.17% of the floral visitors. Female individuals fed on both nectar and pollen while male fed on nectar. Visitation frequency, visitation rate, pollen harvest and pollen deposition of females were significantly higher than that of males because of their larger size and more dry weight. The maximum abundance of females was recorded at 12:00 pm followed by a sharp decline until 4:00 pm whereas males attained their maximum abundance at 2:00 pm. The female pollinated flowers resulted in greater pod weight, pod length, number of seeds per pod, seed weight per pod and germination percentage than the males. Our results suggest that females of A. savignyi deliver better pollination of B. campestris than males in terms of its reproductivesuccess and germination percentage. Future studies should emphasis on exploring the biology and ecology of A. savignyi with special focus of its artificial nesting.

Highlights

Bees (Apoidea: Hymenoptera) are typically considered the most important pollinators of cultivated plant species (Delaplane et al, 2000)
We focused on A. savignyi for further studies as both the male and female individuals were frequently available throughout flowering season
Andrena savignyi was the most frequent floral visitors of B. campestris and comprised 52.17% of the floral visitors followed by Apis dorsata (23.01%), A. florea (13.97%) and Lasioglossum albescens (1.01%)

Summary

Introduction

Bees (Apoidea: Hymenoptera) are typically considered the most important pollinators of cultivated plant species (Delaplane et al, 2000). They use nectar and pollen for meeting their energy requirements and raising brood (Bohart & Nye, 1956; Roswell et al, 2019; Rodney & Purdy, 2020). Female bees feed nectar from flowers to meet their energy requirements used for construction, maintenance and protection of their nests. Besides this they gather abundant pollen grains for their young ones (Ostevik et al, 2010; Smith et al, 2019). They usually have high visitation frequency, better capability of utilizing anthesis timing, shorter foraging range and ability to deposit more viable pollen grains than the males (Ne’eman et al, 2006, Akram et al, 2019)

Methods

Results

Conclusion