Aggregation behavior in the European earwig: Response to impregnated shelters

• Aggregation behavior of European earwig was confirmed in field conditions in apple orchards.
• The number of earwigs required to impregnate a shelter and the duration of such impregnation was determined.
• A shelter impregnated by 0.2 individuals/cm2 over one week was observed to attract earwigs during 5 weeks.
• Such impregnated shelters could be used to promote earwigs in pip fruit orchards and to remove them from stone fruit ones.

The European earwig Forficula auricularia Linnaeus (Dermaptera: Forficulidae) is a key predator of pests in pip fruit orchards; however, this insect can also cause economic damage in stone fruit crops. Pheromone-impregnated shelters may be useful to promote earwigs in orchards devoted to pip fruit and also to capture them in those used for stone fruit production. By using corrugated cardboard traps in four orchards during two years, we observed the aggregation behavior of European earwig in canopies. Under laboratory conditions, corrugated cardboard shelters impregnated by 0.2 individuals/cm2 over one week attracted earwigs for 5 weeks within a range of 50 cm. Future field work should examine the potential of impregnated shelters to promote earwigs in pip fruit orchards and to remove them from stone fruit ones.