AGGREGATION BEHAVIOR AND INTERSPECIFIC RELATIONSHIPS IN DERMAPTERA

The rate of gregariousness and intra- and interspecific attractivity w ere evaluated under laboratory conditions in five species of Dermapter a. The three species of the genus Forficula (Forficula auricularia L., F. decipiens Gene and F. pubescens Gene) showed distinctly gregarious behaviour in old larvae and adults in the pre-reproductive phase. Thi s gregariousness was seen at the intraspecific lever and also among in dividuals of different species. The other two species, Labidura ripari a Pallas and Euborellia moesta Gene, were randomly distributed over th e available shelters, with no distinct tendency for aggregation or iso lation. In individual tests, insects of all five species were attracte d by shelters previously visited by conspecifics in preference to cont rol shelters. For the two non-gregarious species, this phenomenon migh t function as a burrow marker. The same tests showed an interattractiv ity for four of the species studied. Only L. riparia did not respond t o the trails of the four other species, although its trails were attra ctive to the other species, The pheromonal nature of the substances in volved in the interspecific relationships and the involvement of behav iour in the biology and speciation of Dermaptera are discussed.