Robust long-term social memories in a paper wasp

Michael J. Sheehan and Elizabeth A. Tibbetts Supplemental Methods In early spring 2007, emerging P. fuscatus were collected in and around Ann Arbor, Michigan. After emerging from diapause, wasps do not immediately begin nest construction, but rather spend up to a few weeks assessing potential nest sites. During this time, they also engage in aggressive dominance contests with multiple other foundresses [S1], possibly assessing potential co-foundresses. Prior to this experiment, wasps were housed with approximately 10 other wasps from the same collection location (mean + SE. = 10.38 + 0.50, range = 9-13, mode = 10, n = 8 cages) for one week. All collection locations were separated by at least 1 km, and most by more than 20km to ensure wasps from different collection locations had not previously interacted. In total, the aggressive interactions of 50 focal wasp queens were followed over the entire length of the experiment. On the first trial (Day 0), focal wasps were introduced to a new wasp that was collected from a distant location, with whom they had not previously interacted. The first two hours of their encounter were filmed and then the pair of wasps were housed together for one day. After one day together, the wasps were separated and returned to their initial housing situations. On the sixth day after the separation (Day 6), focal wasps were paired with a new and different social partner and their interactions were filmed for two hours. After the two-hour trial, the wasps were returned to their initial housing situation. Similar procedures were used on Days 7 and 8. On Day 7, the focal wasp was re-paired with the same wasp from Day 0. On Day 8, the focal wasp was paired with another new social partner.