Congruence of epicuticular hydrocarbons and tarsal secretions as a principle in beetles

Within beetles, those species that are adapted to life on plants have developed widened tarsi with specialised hairy attachment structures. The capability to adhere to smooth surfaces is based on a liquid film on the surface of these structures, the composition of which is similar to the cuticular lipids. By means of a cluster analysis based on chemical similarities between samples obtained from tarsi or elytra of 35 species using solid phase microextraction, the present study strongly suggests that this chemical congruence is a principle in beetles. This supports the idea of tarsal liquids being part of the cuticular lipid layer and contributes to the understanding of liquid-mediated attachment systems.