Fig. 3.

Footprints left by tarsal setae of Monochamus alternatus after bringing them in contact with and subsequently remove them from a gold-covered resin surface visualized by cryo-SEM; male (a, b, d, e, h, i); female (c, d, f, g.). a. 3rd to 5th tarsomeres close to their print on the surface from where they were detached during freezing and vacuum procedure. b–h. Residues of footprints. i. Terminal adhesive setae on a male foreleg’s tarsus for comparison with the dimension of footprints (a-h). cl, claw; ta, tarsus; ts, tactile setae; wf, presumably watery fluid; of, presumably oily fluid; arrows indicate contamination with wood particles; arrow heads point to oily fluid residues