Philotelma Becker, 1896

Costa, Daniel N. R., Mathis, Wayne N., Marinoni, Luciane & Sepúlveda, Tatiana A., 2024, Phylogeny and taxonomy of the shore-fly tribe Scatellini (Diptera: Ephydridae: Ephydrinae), Zoologia (e 23100) 41, pp. 1-35 : 18-19

Philotelma Becker, 1896

Figs 16 , 24, 25, 47 , 74–81

Philotelma Becker 1896: 163 (neuter). Type species: Philotelma anomalum Becker 1896 (= Notiphila nigripennis Meigen 1830 ), monotypy. – Zatwarnicki and Baéz 1991: 209–210 [review]. – Mathis and Zatwarnicki 1995: 261–262 [world catalog]. – Mathiset al. 2009: 121–158 [revision].

Pseudoscatella Becker 1902: 298 (feminine). Type species: Notiphila nigripennis Meigen 1830 , monotypy. – Becker 1903: 46 [synonymy].

Diagnosis. Philotelma can be distinguished from other genera of Scatellini by the following combination of characters: infuscate spot over crossvein dm-m; male sternite short and bearing spine-like setae; female sternite 8 bearing prominent setulae; aedeagus with a sclerotized basiphallus and a membranous distiphallus; gonite and hypandrium separate. Other characters important to differentiate Philotelma , include the following: arista pectinate; gena small (gena to eye ratio <0.2); posterior notopleural seta inserted at the same level of anterior seta; wing with faint white spots; crossvein dm-m covered with dark spot.

Description. Small to moderately small shore flies, body length 1.20–2.10 mm; generally dark colored, grayish brown to blackish brown.

Head ( Fig. 16 ): Frontal vitta shiny, sparsely microtomentose, 2 lateroclinate fronto-orbital setae, 2 much smaller fronto-orbital setae alternating with larger setae. Antenna short, dark; basal flagellomere round; arista pectinate, bearing 5–6 dorsal, hair-like rays. Face conspicuously protruding, with an interfoveal, dorsal hump; facial setae conspicuous, 1–2 lateral facial setae curved laterodorsally; long ventroclinate setae along oral margin. Eye nearly round. Gena small (gena to eye ratio <0.2); a row of setulae at the ventral margin of gena, without a distinct genal seta.

Thorax: Mesonotum generally dark colored; acrostichal setulae short, in 2 distinct rows, lacking larger, prescutellar setae; dorsocentral setae 3 (1+2); posterior notopleural seta inserted at the same level of anterior seta; basal scutellar seta much shorter than apical seta. Wing faintly to moderately infuscate, with pale white spots; costal vein relatively long, extended to vein M 1; crossvein r-m distinctly distal to subcostal break; crossvein dm-m covered with infuscate spot that usually extends into cell r5. Legs typical, without distinct setae; tarsi light brown; tarsal claws conspicuously curved and puvilli present below each claw.

Abdomen: Tergites shiny black, sparsely microtomentose; sternite 5 of male present, sternite 6 absent. Male terminalia ( Figs 74–81 ): Epandrium in posterior view broadly oval, ventral margin usually slightly to obviously flatter than dorsal margin, sometimes with medial projection, in lateral view elongate, height 3–4x width, bar-like, ventral margin usually pointed or somewhat projected; cerci semihemispherical to broadly lunate; cercal cavity in dorsal 1/4–1/3 of epandrium, broadly oval, as wide as high; surstyli not evident, probably fused indistinguishably with ventral margin of epandrium; gonites paired, one on each side, in ventral view both gonites together forming a V-shaped structure, with vertex (apicomedial convergence of gonite from each side) apically, usually lacking a ventral process; aedeagus in lateral view with basal portion conspicuously excavate dorsally, apical portion variously shaped, in ventral view usually broadly to narrowly oval, sometimes lateral margins angulate, with a membranous distiphallus (sometimes not extended or inflated or even protruding through basal opening of aedeagus); phallapodeme in lateral view narrow, elongate, shallowly curved, with more curvature toward attachment with base of aedeagus, in ventral view T-shaped, with bar of T at basal attachment with aedeagus; hypandrium in ventral view usually broadly Y-, U-, or V-shaped, with extended arms touching basal portion of gonite. Female Terminalia ( Figs 24, 25, 47 ): sternite 7 lacking (character 99[1]); sternite 8 divided, as 2 lateral, subquadrate sclerites, bearing a long seta on posterior margin; female cerci without prominent setae. Ventral receptacle without operculum, only extended process present.

Distribution. Holarctic.

Remarks. Philotelma is a small genus of six species, and thus far, it is only known from the Nearctic and Palearctic Regions. Adults usually occur in habitats that are slightly to notably alkaline or saline ( Dahl 1959). Mathis et al. (2009) published a revision of all known species.

In the phylogenetic analysis, the two species of Philotelma cluster together and their common node is the sister group to the node giving rise to Limnellia and Scatophila .

Figures

Figures 10–23. Head, wing and legs characters: (10) Limnellia sp., head anterior; (11) Scatella (Scatella) sp., head anteri- or; (12) Scatella (Parascatella) sp., head anterior; (13) Hyadina sp., head lateral; (14) Scatella (Parascatella) pilifera, head anterior; (15) Scatella (Scatella) stagnalis, mouth parts; (16) Philotelma sp., head lateral; (17) Physemops nemorosus, head anterior; (18)Ephydra riparia, mouth parts; (19) Scatophila caviceps, wing; (20) Scatella (Scatella) stagnalis, wing; 21, Dagus rostratus, wing; (22) Scatophila mesogramma, male, mid femur posteroventral; (23) Scatella (Scatella) stagnalis, male, fore femur anteroventral.

Figures 24–47.Abdominal sternites and terminalia: (24)Philotelma sp.,female; (25)Philotelma sp.,male;(26)Ephydra (Ephydra) riparia, female; (27) Scatella (Scatella) stagnalis, female; (28) Scatella (Scatella) tenuicosta, female; 29, Scatella (Scatella) tenuicosta, male; (30) Scatella (Scatella) paludum, male; (31) Lamproscatella sibilans, epandrium and cerci, posterior; (32) Haloscatella arichaeta, epandrium andcerci,posterior;(33)Haloscatella karekare,epandrium and cerci,posterior;(34)Hyadina sp., aedeagus lateral;(35)Parydra aquila, aedeaguslateral;(36)Thinoscatella lattini, internal structures ofmaleterminalia (aedeagus[shaded], phallapodeme, gonite+hypandrium), lateral; (37) Diedrops steineri, aedeagus, lateral; (38)Lamproscatella sibilans, internal structures of maleterminalia (aedeagus [shaded],phallapodeme,gonite+hypandrium),ventral;(39)Lamproscatella sibilans, internal structuresof maleterminalia(aedeagus[shaded],phallapodeme,gonite+hypandrium), lateral;(40)Haloscatella arichaeta epandrium and cerci, lateral; (41) Haloscatella arichaeta, internal structures of male terminalia (aedeagus [shaded], phallapodeme, gonite+hypandrium),lateral;(42)Haloscatellakarekare,internal structures of maleterminalia (aedeagus[shaded],phallapodeme, gonite+hypandrium), ventral; (43) Haloscatella karekare, internal structures of male terminalia (aedeagus [shaded], phallapodeme, gonite+hypandrium), lateral; (44) Paracoenia bisetulosa, ventral receptacle lateral; (45) Notiocoenia paniculate, ventral receptacle lateral; (46)Scatella (Scatella) stagnalis, ventral receptacle lateral; (47)Philotelma defectum, ventral receptacle lateral.

Figures 63-85. Male terminalia: (63–65) Notiocoenia acutella; (66–67) Halmopota mediterranea; (68–70)Limnellia huachuca; (71–73) Limnellia itatiaia; (74-77) Philotelma nigripenne; (78–81) Philotelma rossii; (82–83) Scatella (Synhoplos) neglectus; (84–85) Lamproscatella occidentalis.