Key to Subfamilies of Cecidomyiidae This key will delimit the Cecidomyiinae from the remaining five subfamilies of Cecidomyiidae. Recent keys to genera of these other subfamilies are: Jaschhof & Jaschhof (2008) for Catotrichinae, Jaschhof & Jaschhof (2009) for Lestremiinae and Micromyinae and Jaschhof and Jaschhof (2013) for Winnertziinae and Porricondylinae. These five subfamilies are associated with fungi or rotting vegetation, niches quite different from those inhabited by most Cecidomyiinae. Keyed here are three porricondyline genera, Asynapta Loew, Camptomyia Kieffer and Parasynapta Panelius. Larvae of the first two, while presumably mycophagous, are occasionally encountered with plant parts, e.g., cones of conifers. 1 Legs with 5 tarsomeres, the first longer than second (figs 1–2). Ocelli usually present (fig. 1)......................... 2 - Legs either with five tarsomeres, the first much shorter than second (fig. 3), or with fewer than 5 tarsomeres. Ocelli absent.. 4 2 Rs distinctly longer than crossvein r-m; M4 arising from M........................................... Catotrichinae - Rs not appreciably longer than crossvein r-m; M4 free or, exceptionally, absent (figs 1–2; cf. to fig. 62 for venation)....... 3 3 M1+2 forked, the fork longer than the stem (fig. 1).................................................. Lestremiinae - M1+2 forked or not; if forked, tines shorter than the stem (fig. 2)....................................... Micromyinae 4 Legs with fewer than 5 tarsomeres................................. Winnertziinae (in part, most of tribe Heteropezini) - Legs with 5 tarsomeres................................................................................. 5 5 Male gonocoxites not fused ventrally (fig. 105). Female cerci one-segmented (as for fig. 231) (except in Didactylomyia (fig. 230), which has 13 flagellomeres, the 13th shaped as for fig. 27). Rs rarely as strong as other veins (fig. 63), reduced to a stub (fig. 74) or absent (fig. 64).................................. Cecidomyiinae (see separate key to genera that follows) - Male gonocoxites fused ventrally (fig. 108). Female cerci two-segmented (as for fig. 230), except one-segmented in Dirhiza, and then cerci much higher than long. Rs usually as strong as other veins (figs 3–4)................................. 6 6 Flagellomeres with any multiporous, translucent sensoria linear or curved, not girdling the node (fig. 24)................................................................................................. Winnertziinae (remainder) - Flagellomeres with translucent sensoria girdling the node (fig. 25)............................................... 7 7 Antenna usually with 15 or more flagellomeres (fig. 4), rarely with fewer. Tergites with posterior margin weakly sclerotized medially, the numerous posterior setae displaced into a discrete group on each side..................................................................................................... Porricondylinae (in part, tribe Asynaptini) 8 - Antenna with 14 or fewer flagellomeres (fig. 3). Tergites with posterior margin more or less evenly sclerotized and row or rows of posterior setae continuous across tergite or nearly so.................................. Porricondylinae (remainder) 8 Wing with M4 present, either parallel with CuA to point of origin (as for fig. 3) or both veins joined to form a fork (fig. 4)........................................................................................ Asynaptini (in part) 9 - Wing with M4 absent................................................................. Asynaptini (remainder) 9 M4 entirely separate from CuA (as for fig. 3).................................................... Asynapta Loew Cosmopolitan, 46 spp., mycophagous, some found between cone scales of conifers or associated with rot on living plants; 12 Nearctic. - M4 joining CuA some distance beyond base (fig. 4).......................................................... 10 10 Antennal scape with a cluster of setae medially.............................................. Camptomyia Kieffer Cosmopolitan, 67 spp., mycophagous, some found beneath dead bark of various trees, a few between cone scales of conifers; 8 Nearctic. - Antennal scape without a cluster of setae medially.......................................... Parasynapta Panelius Holarctic, 2 spp., mycophagous, larval biology unknown; 1 Nearctic.

Published as part of Gagné, Raymond J., 2018, Key to Adults of North American Genera of the Subfamily Cecidomyiinae (Diptera: Cecidomyiidae), pp. 401-457 in Zootaxa 4392 (3) on pages 404-405, DOI: 10.11646/zootaxa.4392.3.1, http://zenodo.org/record/1196055