On Monogyny of the Four-Eyed Fir Bark Beetle Polygraphus proximus Blandf. (Coleoptera, Curculionidae: Scolytinae) and Its Reproductive Behavior

摘要

The reproductive behavior of the four-eyed fir bark beetle Polygraphus proximus Blandf, an invasive pest of the Siberian fir, was studied. Monogyny of this species was demonstrated in an experiment with colonization of fir logs by groups of adults with a given sex ratio. The female of P. proximus can build several egg galleries and has a mean fecundity of 45 ± 15 eggs. The main elements of intraspecific (reproductive and agonistic) behavior of P. proximus inside the galleries are described in detail. The four-eyed fir bark beetle has some behavioral patterns which are typical of more advanced species of the same genus, such as male entry hole initiation. Comparative analysis of the reproductive behavior and phylogenetic studies of the representatives of the genus Polygraphus Erichson may clarify the functional role of evolutionary transition from monogyny to polygyny in bark beetles.