Commentary: Do Bees Play the Producer-Scrounger Game?

A commentaryon:Foraging Bumble Bees Weigh the Reliability of Personal and Social Informationby Dunlap,A.S.,Nielsen,M.E.,Dornhaus,A.,andPapaj,D.R.(2016).Curr.Biol.26,1195–1199.doi: 10.1016/j.cub.2016.03.009Copy-when-uncertain:bumble bees rely on socia information when rewards are highly variableby Smolla,M.,Alem,S.,Chittka,L.,andShultz,S.(2016).Biol.Lett.12:20160188.doi:10.1098/rsbl.2016.0188International audienceGroup-living animals often use social information, in addition to personal sampling, to learn about foraging opportunities. Small-brained insects are no exception (Grüter and Leadbeater, 2014). For instance, inexperienced bumblebees learn to identify profitable flower species by observing conspecifics (Leadbeater and Chittka, 2005). Bumblebees are especially suitable to study insect social learning as they can be easily tested in the lab, allowing for precise control of food resources, individual experience and social cues (Avarguès-Weber et al., 2015). Here we comment on two recent studies showing how bumblebees use personal and social information discriminately to make adaptive foraging decisions, thus setting the scene for complex social foraging dynamics among bees exploiting variable ressources in the field. Writing in Current Biology, Dunlap et al. (2016) report that foragers of the common eastern bumblebee (Bombus impatiens) rely more on social information than on personal information if the former predicts a reward. The authors trained bumblebees to collect sucrose solution in arrays of 12 artificial flowers in which they manipulated personal information (by using yellow or orange flowers) and social information (by marking some flowers with a pinned dried conspecific). During training, each type of information was either fully reliable (100% of flowers rewarded), moderately reliable (83% of flowers rewarded), or unreliable (50% of flowers rewarded) in a full factorial design of nine treatments. Bumblebees were equally successful at associating personal and social information to a reward. However during the test, in which only unrewarded flowers of all four types were used, most bumblebees preferred flowers with a conspecific. For treatments in which social information was moderately or highly reliable, bumblebees always preferred flowers with a conspecific, even if personal information was more reliable. When both information were unreliable, bumblebees did not show any preference. Only, when social information was unreliable and personal information moderately or highly reliable, bumblebees preferred flowers without a conspecific. In another study published in Biology Letters, Smolla et al. (2016) show that buff-tailed bumblebees (Bombus terrestris) rely on social information when personal information is unreliable