Abstract
Many crops are annually attacked by wireworms which cause yield losses or degradation of product quality. Crop protection is carried out preventively through the application of plant protection products. In the absence of recent references concerning the distribution of the main species present in France and the lack of knowledge concerning their biology, it is not possible to predict the risks of attacks by wireworms. Over 700 fields were investigated in order to map wireworm species in France and to identify the main factors involved in the abundance of wireworms and intensity of damage on crops. Data analysis was carried out on maize fields. Soil characteristics (pH, organic matter content, soil texture) and the summer rainfall are factors that influence abundance of wireworms in the soil. Weather conditions encountered before and after planting, rotation type - including the presence of a meadow in the plot or in its immediate environment - are factors that influence the level of damage on maize. These knowledges allow comprehend the risks, but it remains difficult to characterize it precisely for each field. Experiments led in the fields have assessed the pathogenic fungus Metarhizium anisopliae interest for the protection of several crops. Other trials demonstrated effectiveness of glucosinolates provoking a 50% reduction of wireworms attack. Works under controlled conditions highlighted relevance of innovative strategies using macroorganisms (entomopathogenic nematode) or semiochemicals.