Chironomini (Fig. 6)

Antennae not placed on distinct pedestals, Lauterborn organs not situated on pedicels. Seta submenti situated ventrally, on the opposite side of mandible from seta interna. Ventromental plates variable in shape but with very few exceptions well-developed and striated (reduced only in the Stenochironomus complex). A useful character to separate the genera within Chironomini is the structure of sclerites on dorsal surface of head: frons (frontal apotome), clypeus and labrum. Frons is either discrete or fused with clypeus and forms frontoclypeus (rarely, all dorsal sclerites fused to form frontoclypeolabrum – Stenochironomus). In some genera there is a distinct fenestra (Fig. 78) at anterior frons or frontoclypeus, sometimes reduced to smaller mark, line or area with different cuticle. Anterior margin of frons or fronclypeus can be straight, curved, expanded laterally, sometimes crenulated, or with tubercles on surface.