Mesoconius Enderlein

Marshall, S. A., 2015, Mesoconius Enderlein (Diptera, Micropezidae, Taeniapterinae) of Central America, Zootaxa 3914 (5), pp. 525-540 : 526-527

Mesoconius Enderlein

Mesoconius Enderlein 1922: 176 . Type species, infestus Enderlein (orig. des.)

Zelatractodes Enderlein 1922: 169 . Type species, filipes Enderlein (orig. des.) New Synonym Aristobata Frey, 1927: 69 . Type species, melini Frey (orig. des)

Diagnosis. Relatively large, length 14–21mm (14–18mm in Central American species). Anal cell short, arista bare, femora cylindrical (not longitudinally grooved), and abdomen petiolate. Color and chaetotaxy highly variable between species, leg color often variable within species. Fronto-orbitals weak to strong, 1–3 pairs (usually 2); postocellar and outer vertical bristles present or absent, inner vertical bristles rarely absent, present in all Central American species. Lower frons usually elevated, forming a transverse, slightly scooped band in front of frontal vitta; frontal vitta usually broad, slightly raised and sharply tapered in front of ocelli, not traceable to anterior margin and strongly tapered behind the distinctly raised ocellar triangle. Face pale and weakly sclerotized on anterior (ventral) third to half, broadly elevated to narrowly carinate posteriorly (dorsally); frons separated from antennal base (antennal socket entirely exposed); antennae separated by width of scape. Clypeus shining medially, pruinose laterally. Palpus broad, parallel–sided. Thorax with two notopleural bristles, one small dorsocentral bristle, one pair of long apical scutellar bristles and 2–6 small discal scutellar setulae. Wing usually evenly infuscated except for an indistinct preapical clear area that is sometimes partially divided into three transverse patches; some species with clear, uniformly infuscated or distinctly banded wing. One or more fore tarsomeres of male sometimes enlarged and flattened in South American species, fore tarsomeres of Central American species uniform in width. Mid and hind femora densely microsetulose distally, bare and shining basally. Hind femur and tibia without longitudinal groove. Katatergite often at least slightly swollen, sometimes very prominent with a nipple-like central process.

Female: Oviscape short and stout, with upper and lower surfaces fused to form a cylinder. Spermathecae (1+2) and associated ducts typically complex and often species–specific, usually with a distinct ventral receptacle on a broad bursa copulatrix. A relatively thick duct (paired spermathecal duct) leads to the paired spermathecae and a smaller duct (single spermathecal duct) leads to a single small spermatheca, these ducts usually arising independently from the apex of the bursa, but in some species the bursa extends into a short, thick common duct before splitting into the paired and single ducts.

Male abdomen: Male fifth sternite greatly to entirely reduced, sternite 8 large and often different in surface color and texture from preceding tergites, epandrium small and ejaculatory apodeme variable in size. Postgonite minute, basiphallus very small, distiphallus divided into a broad basal part, a prominent phallic bulb, and a variously developed distal part.