Native and Invasive Ants Affect Floral Visits of Pollinating Honey Bees in Pumpkin Flowers (Cucurbita Maxima)

Abstract Global pollinator decline is a major concern. Several factors – climate change, land-use change, the decline of flowers, pesticide use, invasive species – have been suggested as the reasons. The effect of ants on flowers, despite being a potential reason, received less attention. The consequences of ants being attracted to nectar sources in plants vary depending upon factors like the position of the nectar source, the identity of ants, and other mutualists interacting with the plants. We studied the interaction between floral ants and pollinators in Cucurbita maxima and compared the competition exerted by native and invasive ants on the pollinator with the hypothesis that the invasive ants exacerbate more interference competition for pollinators than native ants. The pollinator’s choice, visitation rate and time spent/visit were assessed. Regardless of species and nativity ants negatively influenced all the pollinator visitation traits, such as visitation rate and duration spent on flowers. The invasive ants exerted a higher interference competition on the pollinators than native ants did. Ants despite performing pollination in flowers with generalist pollination syndrome, can be a threat for plant-pollinator mutualism in specialists like monoecious plants. A better understanding of factors influencing pollination will help in implementing better management practices.