Social information use by bumble bees across trophic guilds

Animals can better match their behavior to the current environment and increase fitness by using social information obtained from observing others’ interactions with the environment. Social information is used by an array of insects in various contexts. Bees use social information from conspecifics to learn which flowers have nectar, increasing their foraging efficiency. Bees commonly interact with diverse heterospecific flower visitors that belong to multiple trophic groups including pollinators and nectaring natural enemies. These other species may provide valuable information about nectar availability. We determined how bumble bees (Bombus impatiens) use visual social information from predatory lady beetles (Hippodamia convergens), which consume nectar to increase their reproductive output. We conducted experiments with laboratory-maintained bumble bees freely flying in arenas to test if they could (1) innately recognize lady beetles as sources of social information about nectar, and (2) learn to use lady beetles to gauge nectar availability. Bees did not innately recognize lady beetles as a source of social information but did recognize conspecifics. Bees appropriately learned to associate conspecifics with the presence and absence of food, however bees only learned to associate heterospecific lady beetles with the presence of food and not the absence. Thus, bees can acquire social information from species in different trophic levels that have some resource overlap. However, social information from nectaring predators may not be as relevant to bumble bees or cognitive constraints may limit how bees use such social information.