Insect pollinator diversity and their foraging behaviour in summer sunflower (Helianthus annus L.)

Abstract

A field study on sunflower (Helianthus annuus L.) in Parbhani revealed the diversity, richness, and diurnal activity of insect pollinators. Thirteen species from five orders were identified, with Hymenoptera accounting for the majority (42.0%), followed by Lepidoptera (32.1%) and Diptera, Coleoptera, and Neuroptera contributing 7.2%. Apis mellifera, A. dorsata, A. florea, Trigona iridipennis, and Xylocopa fenestrata were the most common Hymenoptera, with honey bees serving as key pollinators due to their frequent visits and excellent pollen transmission. Pollination was reinforced by lepidopterans (Danaus plexippus, Spindasis vulcanus, Papilio demoleus, Pieris brassicae, Amata bicincta), as well as infrequent Diptera, Coleoptera, and Neuroptera visitors. Hymenopterans demonstrated peak foraging between 10:00 and 14:00 hours, whereas Lepidoptera and other insect groups displayed species-specific temporal patterns. The combined action ensured continuous pollination throughout the day, which increased seed set and output. These findings support previous reports from India, Kenya, and Ukraine, demonstrating the importance of Apis species and pollinators in sunflower ecosystems. Understanding diurnal activity patterns helps to optimize pollination management for higher crop yields.