Virgin queen execution in the stingless bee Melipona beecheii: The sign stimulus for worker attacks

Exécution des jeunes reines chez l'abeille sans aiguillon Melipona beecheii : le stimulus qui déclenche l'attaque des ouvrières

Stefan Jarau , Johan W. van Veen , Ingrid Aguilar , Manfred Ayasse

Stingless bees produce considerable numbers of virgin queens over the year, most of which are superfluous and get executed by the workers. Nothing is known yet about the sign stimulus that releases the worker attacks. In the present study we investigated the queen execution process in Melipona beecheii and found in both behavioral observations and experiments with caged living virgin queens that workers are not attracted to them from a distance by means of volatile chemicals. Furthermore, worker aggression, which is obvious towards virgin queens that run through the nest excitedly with their abdomen enlarged and the wings beating, was lowered to almost zero when we made the queens "behavior-less" by experimentally killing them. Our results clearly show that the sign stimulus for releasing the execution behavior in Melipona beecheii workers is not a chemical stimulus but the virgin queens' conspicuous behavior, which, we hypothesize, could act as a direct measure of their fitness.

Mots clés: stingless bee; Melipona beecheii; virgin queen execution; queen behavior; worker attacks<br>---<br>Melipona beecheii; abeille sans aiguillon; comportement agonistique; comportement de mise à mort; reine vierge; régulation sociale; stimulus olfactif

Domaines: Zoologie des invertébrés; Biodiversité; Ecologie, Environnement; Science des productions animales

Stefan Jarau, Johan W. van Veen, Ingrid Aguilar, Manfred Ayasse. Virgin queen execution in the stingless bee Melipona beecheii: The sign stimulus for worker attacks. Apidologie, 2009, 40 (4), ⟨10.1051/apido/2009022⟩. ⟨hal-00891991⟩