Earwigs, Forficula auricularia, are key generalist predators to a variety of orchard pests.
However, numbers of earwigs have declined in both organic and IPM orchards in recent
years. Both Integrated and Organic fruit growers have tried to re-establish earwig
populations, thus far with little success. To understand earwig population dynamics and to
find measures to increase natural orchard populations, we conducted a detailed
phenological survey of earwigs in orchards. Earwigs were sampled while sheltering during
daytime in artificial refuges. They move into the trees from the third nymph stage onwards.
In most orchards, a small second brood is produced in summer, and this has a positive
impact on population size in fall. We see only minor differences in phenology between
apple and pear orchards, mainly caused by differences in alternative hiding places.
Earwigs show an inexplicable reduction in numbers at the timing of moulting into adults.
When earwig phenology is correlated with pest phenology in apple and pear, its use for
pest control of major pests is clear