Wikipedia
Arachnocoris
Arachnocoris is a small genus of true bugs found in the Neotropics.
It is often found living in the webs of the pholcid spider Mesabolivar aurantiacus ( Mello-Leitão, 1930). It seems to prefer empty webs, possibly utilizing them as a ready-made prey-capture device, and possibly as a site for finding mates.
Members of this genus are often found living in spider web, mostly those of the family Pholcidae. The body of Arachnocoris is adapted for life in spider webs, with white markings on dark ground, similar to the kleptoparasitic spider genus Argyrodes.