By Karin Sternberg and Jenny Cullinan

The chelifer found in South Africa is mostly Ellingsenius fulleri and is believed to be a predator of small mites, wax moth larvae and other arthropods found in the nest debris. They often cling onto the legs of bees and are believed to be spread in this way to other colonies (Geoff Tribe).

When bees swarm, thousands of bees pour out of a nest only to collect a short distance away in a cluster, often on a branch, but otherwise on any other structure. In September 2017 we were watching bees on the move, temporarily clustered under a concrete table, with scout bees heading out to look for possible new nesting sites and, on their return, performing dances on the surface of the cluster (on other bees) as to the location of the nesting sites found. We watched and waited over a couple of days as slowly the number of possibilities and therefore dances diminished, as the colony came closer to a consensus as to the location of their new nesting site. On the third day of watching this intriguing behaviour and to our utter amazement, we noticed that we were not alone in our waiting.

From the edge of the first layer of bees in direct contact with the table, we spotted a number of pseudoscorpions emerging. They appeared to be restless and hungry as they moved out and away from the hanging colony, using their pincers which had fine and relatively long hairs to sensitively feel for food in the cracks and gaps of the table undersurface.

They did not get very far as certain (dedicated?) bees seemed concerned and actively encouraged them back. There was a very clear communication between these two species and they were continually touching each other; the pseudoscorpions using their pincers either in a waving motion or by clasping at the bee, and the bees using their antennae and legs to touch and usher the pseudoscorpions back into the cluster.

From all of the fussing, one could tell that the pseudoscorpions were crucial to the bees. With colony activity and communication between the bees increasing as the colony prepared to leave for their final nesting site, the bees kept a close eye on their fellow-travellers. As more and more surface bees stopped dancing and started almost buzz-running and whirling like dervishes on the surface before pushing their way into the middle of the colony as paths clearly opened up for them, the vibrations and sounds of the bees increased and activity peaked. No doubt this was also a cue completely understood by the pseudoscorpions. For when the colony finally departed for their new nesting site, remarkably not a single pseudoscorpion was left behind. 

 

These observations showed us an extraordinary interdependence between bees and pseudoscorpions, and highlighted how vital each are to the other that these wild bees on the move should take the pseudoscorpions along with them. The pseudoscorpions are absolutely necessary to the health and well-being of a colony and are very much part of the bees’ hygiene. We would be very interested to hear if this has ever been documented before?