Metricus paper wasps ( Polistes metricus; left top) at the University of Michigan have been trained to recognize the individual faces of a related species, the golden paper wasp (Polistes fuscatus), to avoid potential pain. Naturally, P. metricus lacks individual recognition, even among its own nest mates. With the lack of individual color variation and solitary nesting behavior of P. metricus, there has been no evolutionary need for recognition behavior to develop. This is in stark contrast to P. fuscatus (left bottom), whose unique facial patterns and communal nesting reinforces the need for individuals to recognize one another for continued cooperation. Each adult P. fuscatus’ face has a specific pattern, making each wasp uniquely recognizable. By raising individuals of these 2 species together, the normally oblivious P. metricus has gained the ability to not only recognize specific wasp faces, but to associate individual P. fuscatus images with pain and actively avoid them.
This avoidance behavior was achieved by shocking adult P. metricus wasps when shown a picture of a P. fuscatus with a particular facial pattern. Over time, these wasps were able to associate a specific face with the pain of an electric shock. When later given options of two P. fuscatus images on a neutral stage (in previous trials one image had resulted in a shock and the other image did not), wasps actively approached faces that had not previously shocked them. While this behavior might seem obvious, P. metricus wasps raised with their own species were not able to discriminate between shock and no-shock faces; when given a choice, these wasps approached both the shock and neutral faces in equal measure. Thus, even though P. metricus naturally lacks an ability to discriminate between wasps, when raised with P. fuscatus (where recognizing individuals is to their biology) their behavior is able to shift. The normally oblivious P. metricus suddenly becomes able to tell other wasps apart; at least at the level of an image.
This change in cognition demonstrates that wasps may have a level of behavioral flexibility not usually attributed to an insect. In addition, this study sheds light on at least one path of how communication may evolve. Explicit physical differences between related organisms may be an initial step in individual perception; and thus is one of many building blocks toward conspecific communication. So, in a world where humans andother vertebrates appear to reign supreme, are we discounting how mentally advanced insects might be? Wasps did invent paper before humans; after all.
Application of this research could lead to exciting results. Could it be possible to “train” wasps to avoid people? For those who raise wasps and bees, this might be an effective tool for up-keeping nests while reducing the risk of stings. Imagine a world where just your face struck enough fear into a swarm of bees and keep you safe from harm. Maybe this can lead to a real version of “The Wasp” superhero, able to command Vespids to his or her will! True, these ideas may be a stretch at the moment, but who knows? While the full real-world application of this is research yet to be uncovered, it pushes the door further open for how we think about insect learning, behavior, and the evolution of communication.