BENchmarking applied to FORest cockCHAfor ecology to ensure regeneration in a context of forest health crises

PI : Claudine Richter, ONF Département Recherche Développement & Innovation (RDI)

Co-applicants : Nathalie Breda (UMR 1434 SILVA); Louis-Michel Nageleisen (DSF/UMR 1434 SILVA)

Collaborations : Régine Touffait (ONF Département gestion durable et multifonctionnelle des Forêts -GDMF); Vincent Boulanger (ONF Pôle RDI DT Seine Nord); Jérémy Cours (AgroParisTech -GDMF); Christine Micheneau (ONF Département RDI)

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Context — The forest Cockchafer is a beetle species well known for the damages it can inflict to forest ecosystems. Beyond spectacular defoliations occasioned by adults, the larvae feed on the roots of young trees causing severe mortality in forest regenerations. Although eastern European countries had been facing recurrent infestations since the 1960’s, in France, cockchafer populations seem to have turned from endemic to epidemic in the last 10 years, with dramatic damages reported in young forest stands of Picardie and Northern Alsace.

Chemical treatments proved to be efficient but with suspected environmental impacts. A wide diversity of alternative biological control methods had been investigated in Europe, but failed in being ultimately applied in everyday forest management.

Objectives — This project is based on a benchmarking approach of (i) the acquired scientific knowledge of cockchafer biology and (ii) technical experiences accumulated in the European countries that have been subjected to outbreaks in the last decades. We aim at investigating whether changes in forest stands management are able to limit cockchafer population dynamics.

Approaches — First, we will produce a state-of-the-art review concerning the environmental factors which determine cockchafer outbreaks, using standard bibliographic tools and direct enquiries in eastern European countries. Second, we will propose a protocol to describe stand cover structure and ground vegetation characteristics which determine cockchafer larval density.

Expected results and impacts — The review of the existing international scientific literature, contacts among researchers and managers in concerned countries should be established to share the unpublished feedback and experience of on-site actors. A key event will be the organisation of an international working session during autumn 2018, to carry out a framework of hypothesis for the research of ecological solutions to cope with the cockchafer crisis and prevent future outbreaks. Finally, it will initiate the creation of a European skills network.