Facitrichophora, Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012, A revision of the new world species of Polytrichophora Cresson and Facitrichophora, new genus (Diptera, Ephydridae), ZooKeys 231, pp. 1-116 : 7-8

Genus Facitrichophora gen. n.

Type species.

Facitrichophora manza sp. n., by present designation.

Diagnosis.

Small to moderately small shore flies, length 1.8-3.20 mm; generally densely microtomentose, dull species (Figs 11-13). Head (Figs 11-12): Frons lacking anterior, proclinate, fronto-orbital seta; face substantially prominent at level of dorsal facial seta; antennal grooves generally sharply defined ventrally; facial setae comprising at least 2 vertical to verticolateral rows (Figs 11-12), 5 setae of medial row larger than those of lateral row, these not arising from shiny papilla and with similar, mostly inclinate to ventroinclinate orientations; face lacking a distinctly dorsoclinate seta at ventral extremity; parafacial moderately wide, bearing conspicuous, vertical row of large setulae; gena variable but moderately high. Eye generally oval, conspicuously microsetulose, bearing numerous interfacetal setulae; maxillary palpus yellow. Thorax (Fig. 13): Acrostichal setulae in 6-8 rows; a presutural and postsutural supra-alar setae moderately well developed, both about 1/2 length of postalar seta; notopleuron bearing several setulae in addition to 2 larger setae; anterior notopleural seta inserted conspicuously closer to posterior notopleural seta than to postpronotal seta; anepisternum bearing 2 prominent, subequal setae along posterior margin. Wings faintly infuscate, more so toward anterior margin; costa bearing 3-5 long, dorsal setae between humeral and subcostal breaks. Forefemur normally developed, lacking row of short, stout setae along anteroventral or posteroventral surfaces; hindtibia lacking a preapical, ventral, spur-like seta. Abdomen: Tergites variable, but mostly unicolorous; tergite 2-4 of ♂ becoming progressively longer. Male terminalia (Figs 1-4): Epandrium thinly connected dorsally above cerci, in posterior view more or less elliptical, 2 × longer than wide, in ventral half gradually tapered, or pyriform, broader basally and tapered irregularly to apex, on whole surface bearing distinct setae, in lateral view apical half slightly widen by extension of its ventral portion, apical section of ventral margin often with setae; cerci fused ventrolaterally to medial margin of epandrium, in posterior view generally slightly elongate or hemispherical; gonites rod-shaped without setae, rarely lobate; aedeagus strongly elongate, about 4 –6× longer than wide, in dorsal view base generally narrowly triangular, apex rounded, in lateral view trunk of aedeagus with uniform thickness, apex pointed and generally bearing subapically a narrow, membranous flap that generally folds back under aedeagus with about 2/3 length of aedeagus to battered tape 2 × as long as aedeagus; phallapodeme separate from aedeagus, in posterior view elongate with extension at base and bifurcate anteriorly, in lateral view narrowly subtriangular, with extension toward aedeagal base narrow, parallel sided or tapered, keel usually evident toward hypandrial extension, but sometimes reduced; ejaculatory apodeme absent; hypandrium in dorsal view U- or V- to Y-shaped with thickened stem or base, anterior margin narrowly to broadly rounded, posterior arms either straight or oriented posterolaterally, if straight then with a lateral and medial pair of arms, in lateral view hypandrium generally flattened or broadly and shallowly pocket-like.

Distribution.

Species of Facitrichophora have only been found in the Neotropical Region.

Natural history.

Specimens of Facitrichophora are usually associated with mud-shore and sand-shore habitats associated with brackish water in backwater areas of maritime coasts.

Discussion.

Facitrichophora , along with Discocerina , Hydrochasma Hendel (New World), and Polytrichophora , form a monophyletic lineage within the tribe Discocerinini (see Zatwarnicki and Mathis 2001 for background on this node). Facitrichophora may be distinguished from Discocerina , Hydrochasma , or Polytrichophora by the two series of facial setae (see generic description and Figs 11-12) with an inclinate to ventroinclinate orientation; medial facial series larger and numbering 5. These characters are unique to the species of this genus (synapomorphies) and are evidence of its monophyly. Facitrichophora is perhaps most closely related to Polytrichophora and a synapomorphy establishing this relationship is the fusion of the ventral portion of the cerci with the epandrium.

Four species have been discovered in this genus thus far, and each can be distinguished by external characters. Reference to characters of the male terminalia, however, may be needed to confirm a species’ identity.

Key to species of Facitrichophora