Genus Fragosa Miranda gen. nov.

Figs 1–11, 66, 74, 76, 78–83, 92–95

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Type species: Baccha rugosifrons Schiner, 1868

Baccha obscuricornis species group. Hull (1949a)

Baccha victoria species group, in part. Hull (1949a)

Ocyptamus stenogaster species group. Thompson (1981); Mengual et al. (2012, 2018); Miranda et al. (2014, 2016)

Description. Delicate-looking flies. Head. Face very narrow to narrow (around 1/4 to less than 1/3 of head width). Frons usually ~1/3 of head width. Antennal insertions confluent. Female ocellar triangle adjacent or separated by approximately one ocellus-width from lateral eye margin. Dorsal occiput usually with two rows of pile (sometimes with one row). Thorax. Scutum without distinct anterior row of pile. Anterior anepisternum pilose. Katatergite with short microtrichia that gives the sclerite a ‘velvet’ appearance. Metaepisternum pilose. Metasternum bare. Upper calypter margin either bare, with pile shorter than pile on the ventral calypter margin, or with longer darker pile. Metafemur with normal pile. Wing. Alula often absent (some species with a trace of alula, e.g. F. harlequina (Fig. 78) and F. mara). Male wing light brown, usually bare on small basal areas of cells c, r and bm; female wing pigmentation and microtrichosity variable; anal lobe narrowed basally. Abdomen. Abdomen slender; tergum 1 crescent-shaped with lateral extremities directed laterally; terga usually only with quadrangular pale maculae on the baso-lateral corners of terga 3 and 4 (Fig. 2). Terminalia. *Female tergum 7 quadrangular (Fig. 8); female tergum 8 rectangular with concave basal and apical margins; *epiproct partially divided into a pair of separate sclerites connected to each other by a basal narrow strip or more extensively fused, each with baso-lateral apodemes extending into the abdominal cavity (Fig. 8). Male basiphallus teardrop-shaped (Fig. 11), distiphallus membranous with dorsal sclerotized triangular region (Fig. 10).

Etymology. The name is a reference to the ‘brittle’ (Latin), delicate, aspect of these flies. It is to be treated as feminine.

Comments. This genus, equivalent to the former Ocyptamus stenogaster species group, is made up of relatively delicate flies (Figs 1, 2 and 6) superficially similar to Baccha, Leucopodella, and the species of the Pelecinobaccha brevipennis group. Most species lack an alula (Fig. 3), or have it reduced to a barely discernible trace (Fig. 78), and have a reduced anal lobe, very long and narrow abdominal segments, a crescent-shaped tergum 1 with lateral extremities directed laterally (Fig. 66), and (usually) quadrangular pale maculae on the baso-lateral corners of terga 3 and 4 (Fig. 2). They usually have a very long and narrow 2 nd abdominal segment (over 8 times longer than wide) (Figs 1, 2) with a naturally arched tergum giving the segment a cylindrical appearance. The unique condition of the female epiproct (see description above) is distinctive and provides strong evidence for the monophyly of the genus. Facial coloration seems to vary among specimens of the same species.

Fragosa gen. nov. and Hypocritanus gen. nov. share a dorsally sclerotized female cercus with setulae restricted dorsally (Figs 8, 14, 15), however, we consider this condition to be a plesiomorphy since recent phylogenetic analyses always keep them as separate taxa (Mengual et al. 2012; Miranda et al. 2016). Furthermore, a single genus including both taxa would be hard to diagnose, while keeping them separated makes both genera distinct and diagnosable with their own unique characters. Both taxa prey on Pseudococcidae (Hemiptera), and we hypothesize that the Neotropical Fragosa gen. nov. and the Nearctic Hypocritanus gen. nov. probably evolved independently to occupy the same ecological niche, explaining the absence of the other in each biogeographical region.

Based on morphological characters observed, and the sister group relationship of F. titania with the remaining Fragosa in a previous phylogenetic analysis ( Miranda et al. 2016), we propose two species groups for the genus Fragosa gen. nov.: F. rugosifrons and F. tenuis groups.