Contact Sex Signals in Two Sympatric Spider Species, Tegenaria domestica and Tegenaria pagana

Bioassays in two sympatric spider species, Tegenaria domestica and T. pagana, demonstrate that the total female chemical extract, and in particular the polar fraction, are involved in the sexual behavior of males and reproductive isolation mechanisms. In T. domestica female attractiveness was correlated with changes in 18 chemical compounds. In T. pagana little difference was observed between 12 compounds in extracts of attractive and unattractive females. 12- + 10-Methyloctacosane was not detected in attractive females of either species. Reproductive isolation was linked not only to quantitative changes in 18 chemical compounds detected in both species, but also to nine compounds present in one or the other species.