Key to males of species of Malacophagomyia (Malacophagomyia) (males only)

[adapted from Mulieri & Mello-Patiu (2013)]

1 Parafacial and fronto-orbital plate with silvery microtomentum [see figures 1–2 in Mulieri & Mello-Patiu (2013)]; hillae without lobe apically, with rounded or truncated apex [see figures 14, 21 in Mulieri & Mello-Patiu (2013) (as outer arm of lateral stylus)]....................................................................................... 3

- Parafacial and fronto-orbital plate with golden microtomentum [Fig. 2 and see figure 3 in Mulieri & Mello-Patiu (2013)]; hillae with a lobe apically [Fig. 8–9 and see figures 24, 29 in Mulieri & Mello-Patiu (2013) (as outer arm of lateral stylus)]...... 2

2 Tergite 5 with lateral spots of silvery-gray microtomentum (Figs 1, 5); arm of sternite 5 with several fine setae on its inner surface, and a darkened short posterior lobe anteriorly directed (Fig. 6); surstylus thin and elongated, with long apical setae (Figs 8–9); cerci with lateral projections apically (Fig. 7)................................. M. (M.) gaelana sp. nov.

– Tergite 5 with latero-ventral part reddish, with lateral spots of light golden microtomentum [see figure 22 in Mulieri & Mello-Patiu (2013)]; arms of sternite 5 with tufts of strong black spine-like setae on its inner surface and without posterior lobe [see figure 6 in Mulieri & Mello-Patiu (2013)]; surstylus widened and rounded, with scattered setae [see figure 28 in Mulieri & Mello-Patiu (2013)]; cerci without lateral projections apically [see figure 27 in Mulieri & Mello-Patiu (2013)]......................................................................... M. (M.) rivadavia Mulieri & Mello-Patiu, 2013

3 Syntergosternite 7+8 blackish; cerci short (cerci length 2× cerci width), covered with short setae [see figure 12 in Mulieri & Mello-Patiu (2013)]; arms of sternite 5 with several fine setae on its inner surface, and short posterior lobes medially directed [see figure 4 in Mulieri & Mello-Patiu (2013)].................................... M. (M.) filamenta (Dodge, 1963)

– Syntergosternite 7+8 reddish; cerci elongated (cerci length 3× cerci width), covered with long villous setae on basal half [see figure 19 in Mulieri & Mello-Patiu (2013)]; arms of sternite 5 with strong spine-like setae on inner surface, and elongated posterior lobes posteriorly directed [see figure 5 in Mulieri & Mello-Patiu (2013)]..................................................................................................... M. (M.) kesselringi Kano & Lopes, 1968