Original Article

A new transplantation protocol for harvester ant queens Messor barbarus (Hymenoptera: Formicidae) to improve the restoration of species-rich plant communities

Bulot, A., Dutoit, T., Renucci, M. & Provost, E.

Abstract: We present a protocol for the transplantation of founding queens of the harvester ant Messor barbarus (Linnaeus, 1767), monitoring their survival at six months, one year and 18 months. Once established, these ants are expected to have a positive impact on vegetation restoration via their ability to disperse seeds harvested by workers, thus accelerating the rehabilitation and restoration already undertaken using conventional civil engineering. The transplantations were performed on two sites currently undergoing ecological restoration, one previously degraded by intensive fruit growing (AOA) and the other destroyed by an industrial accident (OLA), and compared with natural colonisation on a reference steppe site. Founding-queen transplantation was also performed at the reference steppe site. We report here the first steps of the protocol, with results on transplantation success and on natural colonisation. Short-term rates of survival of the transplanted founding queens are encouraging: 15% at the Aoa site (after one and a half years) and 35% at the Ola site (after one year). It will take a few years longer to assess any significant impact on composition, species richness and distribution of the different plant populations characteristic of the steppe. However, we demonstrate that the density of natural nests is significantly lower at the degraded site (AOA) than at the reference steppe. It also appears that natural recolonisation by Messor barbarus at the destroyed site (OLA) would be difficult without the creation of a favourable habitat. These two results attest to the value of transplantation operations and confirm our hypothesis that for successful establishment the suitability of host habitats for founding queens is a more limiting factor than dispersal during the nuptial flight.