The same number of joints in the tarsi is a character common to very large groups of beetles, but in the Engidae, as Westwood has remarked, the number varies greatly and the number likewise differs in the two sexes of the same species.
Tartsoan giltzarte kopuru bera edukitzea komuna zaio koleoptero talde oso handi bati, baina engidoetan, Westwoodek ohartarazi duen bezala, kopurua asko aldatzen da batetik bestera; eta espezie bereko sexu bietan ere kopurua ezberdina da.