Parasitoid cold-tolerance and overwintering capability

The ability to survive during winter poses one of the most important barriers for establishment of species in temperate climates. To assess, during the biosafety evaluation, whether an exotic natural enemy can establish itself, it is therefore important to know its overwintering strategy and cold-tolerance.

The establishment of exotic natural enemies can be desired when an invasive pest should be targeted by a specialized agent from its native region (classical biological control). However, when negative environmental effects are to be expected, the ability to establish precludes the deliberate release of an exotic natural enemy. Furthermore, cold-tolerance can play an important role for efficacy, for example during cold storage or when a field application is planned during early spring. Surprisingly few, however, is known about the cold-tolerance of parasitoids.

We investigate the cold-tolerance of parasitoids in the laboratory and in the field. Our research comprises different scales of time and temperature, from the supercooling point to the overwintering of different developmental stages in the field. As model systems we use native and exotic parasitoids of drosophila.