Torymus sinensis: a viable management option for the biological control of Dryocosmus kuriphilus in Europe?

Oak gall wasps (Hymenoptera: Cynipidae, Cynipini) are characterized by possession of complex cyclically parthenogenetic life cycles and the ability to induce a wide diversity of highly complex species- and generation-specific galls on oaks and other Fagaceae. The galls support species-rich, closed communities of inquilines and parasitoids that have become a model system in community ecology. We review recent advances in the ecology of oak cynipids, with particular emphasis on life cycle characteristics and the dynamics of the interactions between host plants, gall wasps, and natural enemies. We assess the importance of gall traits in structuring oak cynipid communities and summarize the evidence for bottom-up and top-down effects across trophic levels. We identify major unanswered questions and suggest approaches for the future.

More than 5000 introductions of about 2000 species of exotic arthropod agents for control of arthropod pests in 196 countries or islands during the past 120 years rarely have resulted in negative environmental effects. Yet, risks of environmental effects caused by releases of exotics are of growing concern. Twenty countries have implemented regulations for release of biological control agents. Soon, the International Standard for Phytosanitary Measures (ISPM3) will become the standard for all biological control introductions worldwide, but this standard does not provide methods by which to assess environmental risks. This review summarizes documented nontarget effects and discusses the development and application of comprehensive and quick-scan environmental risk assessment methods.