ABSTRACT
Head elongate-quadrate, weakly deflexed, inserted slightly into the prothorax. Eyes relatively large, entire, finely facetted, lacking interfacetal setae. Antennae reaching at least middle of prothorax, but not beyond middle of elytra. Antennae with 11 antennomeres in both sexes; males flabellate, or females serrate. Antennae inserted into prominent antennal tubercles directly above the bases of mandibles; scape three times the length of pedicle. Males with antennomeres 3-11 8-10 times broader than long. Females with antennomeres 10-11 flattened, fused, all antennomeres 2-4 times broader than long. Labrum small, bilobed, appearing fused to head. Clypeus small and triangular. Mandibles generally large, well-sclerotized, visible in ventral view; apex strongly and abruptly curved mesally, unidentate, truncate or rounded. Dorsal surface smooth, flattened; ventral surface with a deep, concave depression at the innermost median half. Adoral face of mandible with a single tooth. Maxillae with cardo small; stipes often covered by lacinia; galea well-developed, apically densely setose or spinose; lacinia reduced. Maxillary palpi 4-segmented; palpomere small, remaining segments subequal in length and setose. Gula distinct, U-shaped, forming the ventral exoskeleton of the head; gular sutures distinct and separated. Labium
divided into a subtriangular, plate-like mentum and reduced submentum; distal margin of mentum with small, rectangular palpiger, 3-segmented labial palpi, and mesal, conical, setose ligula.
