Diversity and Role of Flower Visitors in Onion Seed Production

Onion flowers attract a wide range of visitors, including pollinators. Many factors influence the abundance of floral visitors in onion, such as flower size, shape, colour, weather parameters and the availability of floral rewards. Quality seed production in onion (Allium cepa L.) is mainly driven by insect pollinators because of its protandrous nature and cross-pollination. The type of flower visitors, their numbers and the time of their visitation determine the pollination efficiency. Bees are the major pollinating agents in onions under natural conditions. However, using chemical pesticides against pests and diseases of onions during bloom decreases the diversity in and around crop fields. Anthropogenic factors like urbanization could have negative impacts on insect pollination services. Therefore, it is critical to adopt a sustainable approach to retain and conserve the existing insect pollinators and their diversity in the onion ecosystem. In this study, we review the research work done so far on the diversity and role of flower visitors and pollinators in onion seed production and the various factors affecting their survival and services in the onion ecosystem.