Pollinator Community of Sunflower (Helianthus annus L.) and its Role in Crop Reproductive Success

A study was carried out to identify the pollinator community and its role in pollination of sunflower at the research farm of Bahauddin Zakariya University, Multan, Pakistan. The community of pollinators was composed of 14 insect species including eight bee species (Hymenoptera), four fly species (Diptera) and two butterfly species (Lepidoptera). Bees were the most abundant floral visitors. Apis dorsata Fabricius, Xylocopa sp and Megachile sp. were the most abundant among the bees with the highest visitation frequencies i.e. 1.33, 0.07 and 0.06 individuals per head per minute, respectively. The abundant flies included Eristalinus aeneus Scopoli and E. arvorum Linnaeus. The peak visitation activity of pollinators was recorded between 08:00 to 10:00 hrs. Although there was no significant difference in number of seeds per head produced in insect pollinated (open) as compared with, without insect pollinated (caged) heads. However, insect pollination significantly increased the number of healthy seeds, 100 seed weight and germination percentage. As A. dorsata Fabricius was the major pollinator of sunflower, future studies should focus on its conservation for better crop production.