Epigeal phase of the biological cycle of Forficula auricularia Linnaeus (Dermaptera: Forficulidae) in eastern Canada
AbstractThe population structure of the European earwig, Forficula auricularia Linnaeus (Dermaptera: Forficulidae), was investigated in three sites in eastern Canada (Montréal, Québec; Fredericton, New Brunswick; Truro, Nova Scotia), with two goals; describe the seasonal trends of the epigeal phase, and ascertain if the three studied populations belong to sibling species “A”, as opposed to sibling species “B” found in Vancouver, British Columbia, Canada. Insects were collected using wooden grooved traps placed on lawns and tree trunks; traps were checked weekly from the first spring melt of the frost barrier until after autumn first frost (epigeal phase). The epigeal phase was short, about five months. The different instars and adults showed a single peak of abundance. No first instars, few second instars, and mostly fourth instars and adults were collected in the arborescent stratum. The data demonstrated that these three populations have the same epigeal phenology. The interbreeding experiment established that the three studied populations belong to the same sibling species (A) of F. auricularia, and differ from sibling species (B) from Vancouver. I suggest that the climatic conditions in eastern Canada are like those in other world regions where sibling species “A” is present, and that these regions represent the edge of the bioclimatic environment of this species because of its limits on reproduction.