South American Melolonthinae (Coleoptera: Scarabaeidae) classification and nomenclature: some problems and solutions Author Smith, Andrew B. T. Research Division, Canadian Museum of Nature P. O. Box 3443, Station D Ottawa, ON, K 1 P 6 P 4, CANADA asmith @ mus-nature. ca text Insecta Mundi 2008 2008-12-05 2008 60 1 28 journal article 10.5281/zenodo.5170193 1942-1354 5170193 17196FAF-00D5-438D-9994-C5BAA2E6AE90 Tribe Sericoidini Diagnosis . The tribe Sericoidini is distinguished from other Melolonthinae using the following combination of characters: labrum beneath clypeus, not on same plane; clypeus and labrum separate (with labrum protruding beyond clypeus in dorsal view) or fused (with a suture distinguishing the parts); antenna with 8-9 antennomeres (including 3-5 antennomere club); mesosternal / metasternal process absent; abdomen with 6 ventral sternites (basal sternite partially hidden by metacoxae), sternites approximately equal in length, evenly convex, separated by distinct sutures; tergite and ventrite of abdominal segments entirely distinct, separated by complete longitudinal suture or ridge (absent in Ulata ); metatibiae with 2 apical spurs, spurs set below and above the tarsal articulation (tarsus moves between tibial spurs); all claws symmetrical. Remark . The definition of the tribe Sericoidini is refined above and now includes the following genera: Apterodemidea Arrow , Blepharotoma Blanchard , Sericoides Guérin-Méneville , and Ulata Saylor. The tribal status of Apterodemidea and Ulata is somewhat unclear and warrants further investigation. Sericoidini is endemic to the southern half of South America and shares characters with several Australian tribes including Automoliini, Liparetrini , Maechidiini, Scitalini, etc.