epizygum
From ZooTerms (Dictionary of Invertebrate Zoology)
epizygum (noun; plural epizyga; Greek epi, upon; zygon, yolk): (Arthropoda: Insecta) In certain beetle larvae, an elongate plate or bar extending from the zygum toward the clithrum on the right of the epipharynx, or embodied in the tylus; may be present when clithrum is absent.
