Sphaerion sp. Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); procoxal process expanded apically (Fig. 18); mesal antennal spines present (Figs. 8b, 9b); Pronotum with impunctate regions present; femoral carinae absent; procoxal cavities closed laterally (Fig. 24); femoral apices rounded (Fig. 26); femora clavate (Fig. 37b); elytra not metallic and without dense pubescence; posterior procoxal cavities open (Fig. 18); pronotum without transverse ridges; mesotibial carinae present (Fig. 22); pronotum and head without dense yellow or white pubescence; antennomeres carinate but not sulcate (Fig. 45b, c); spine of antennomere three acute (Fig. 45b); antennomere shape linear, not expanded at apices (Fig. 22); lateral pronotal tubercles present (Fig. 12e, f); elytral apices produced acuminately causing shift of apicolateral spine to apicomedial location; elytra and pronotum with dense vestiture of short pubescence; antennomere three of males longer than pronotum (Fig. 46c); pronotal punctation not alveolate and partially obscured by pubescence; metepisternal notch with slight protuberance. Length: 10-15 mm.

Distribution and Diversity.--México to Central America, Argentina, Bolivia, Brazil, French Guyana, Paraguay, Peru, Uruguay. Nine species.

Discussion.--Sphaerion is apparently closely related to Mephritus and Miopteryx based on the implied weighting phylogenetic analysis (Figs. 50, 60). More taxa within these genera should be analyzed to see if consistent characters persist to separate them and a focussed phylogenetic analysis should be made to determine if they are paraphyletic with respect to one another.

Sphaerion, Mephritus, and Miopteryx all share the characteristic elytral apex, with the apicolateral spine shifted to an apicomedial position and loss of the sutural spine. The examined Sphaerion differ in having the procoxal cavities closed laterally while the examined Mephritus and Miopteryx specimens had this open. Mephritus and Sphaerion vary as to the development of lateral pronotal tubercles, although they are absent in Miopteryx.