Morphology of the head and associated structures in New World Cryptocephalini (Coleoptera: Chrysomelidae: Cryptocephalinae)

Comparative morphology of the head and associated structures of Cryptocephalini was studied based on representatives of 13 of the 14 New World genera. The study revealed sets of characters of obvious diagnostic and phylogenetic value which supported most currently recognized genera. The heads of New World Cryptocephalini are simplified in terms of sutures and sulci compared to other chrysomelids. Main features that distinguish genera are interocular distance, eye and antennal shape and size, the presence or absence of setae, and gular and genal areas. A series of common characteristics were found among the subtribes Cryptocephalina and Monachulina, while Pachybrachina differed in all. The genus Mylassa was found to share all the characters found in Pachybrachina.