Effects of food availability during the nesting phase on growth and survival of the common earwig Forficula auricularia
Abstract: The common earwig Forficula auricularia L. (Dermaptera: Forficulidae) is a generalist predator that plays an important role in the natural control of orchard pests such as woolly apple aphid (Eriosoma lanigerum Hausmann) and pear sucker (Psylla pyri L.). In this work we study the effects of food availability during the nesting phase on the growth and survival of young earwigs.Soil samples were taken in ten pear orchards in order to investigate the available soil biota. Using PCR techniques, we determined what kind of food the mothers and their young consume in the field. The effect of the different food sources on earwig offspring development was tested in the laboratory.Acari and Collembola made up for 97% of the soil sample content. Analysis of stomach contents showed that first and second instar earwigs feed on a wide range of food sources in the field, including Collembola, mites, Isopods and plant material. Differences in diet had a significant effect on body weight (and other parameters) in the laboratory. These results can be used as a starting point to adapt orchard soil management in order to optimise the conditions for nesting earwigs.