PHEROMONAL BASIS OF AGGREGATION IN EUROPEAN EARWIG, FORFICULA-AURICULARIA L (DERMAPTERA, FORFICULIDAE)

The aggregation behavior of the European earwig Forficula auricularia was investigated. Bioassays of frass extracts, cuticular washings. and the defensive exudate have been conducted to locate the source of an aggregation pheromone, and aggregation behavior has been demonstrated with extracts of frass and the washings of male cuticular lipids. Chem ical investigations revealed the presence of a unique pattern of typic al normal, monomethyl-, and dimethylalkanes, along with a series of fa tty acids and the well-known defensive quinones from these insects. It has been concluded from the bioassays of a number of authentic compou nds and the lack of a chemically discernible difference between male a nd female extracts that the aggregation pheromone of F. auricularia is quite probably a minor component of the male cuticular lipids,