Krifomyia minutissima ( Bezzi, 1908 ) Ebejer, 2009

Ebejer, Martin J., 2009, A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera, African Invertebrates 50 (2), pp. 321-321 : 412-415

Krifomyia minutissima ( Bezzi, 1908) , comb. n.

Figs 56 , 57

Rhicnoessa minutissima: Bezzi 1908: 200 .

The type material consists of 1ơ and 1^from Namibia, both in poor condition, preserved together in 70 % alcohol. The male was partially dissected by Munari ( Munari 1994) who was the first to recognize that this species did not belong to the Tethinidae (now a subfamily of the Canacidae ), but to the Chyromyidae . The head of the male was separated from the body, as were a wing (the other missing) and the abdomen. The thorax has one of each of the fore, middle and hind legs, the rest are missing. The abdomen is squashed and partly macerated. The female is badly shrivelled, but retains most of its parts. Nevertheless, there are sufficient discernible characters to allow me to confidently assign to this species a number of specimens collected more recently, also from Namibia, which are better preserved. The descriptions and drawings are based on these specimens.

Redescription:

Male.

Head: All yellow; in profile rectangular and almost twice higher than long; fr broad and parallel-sided, about 3× width of eye viewed from in front, protruding above and in front of eye margin viewed in profile; with about 10 short and fine setulae scattered on it; eye oval, gena deep, at middle equal to or greater than height of eye and with wide postgenal dilation; several short fine pale setulae scattered over lower part, postgenal seta absent; face with very broad carina extending from lunule to below antennae, leaving from this level to buccal margin a relatively large rectangular sclerotized area; antenna in deep fossa, segments 1 and 2 not visible, segment 3 rounded except for shallow dorsal excavation near insertion of arista; arista with 3 segments, a little shorter than is usual for this family, first 2 segments and base of segment 3 pale; 2 short reclinate orb and one fine setula in front, 1 vti and 1 vte, both shorter than is usual in this family, oc setae divergent, pvt minute and parallel, sometimes absent, few postocular setulae in one row; mouthparts all yellow, well-developed with long proboscis, geniculate labella and narrow elongated palp.

Thorax: Yellow, often with longitudinal pale brown scutal stripes, pleura always yellow. Chaetotaxy: scut yellow dorsally but with dark spot laterally at base continuous with a dark brown line along entire lower border of scut; 1 short pprn and 1 short posthu, a minute but distinctly incurved ihu, 2 ntpl, 1 pa, 1 short post ia, 1 dc, scutal setulae very short and fine in 4–6 irregular rows, 1 anepisternal closer to upper margin; absent sa and katepisternal setae; scut with 2 pairs of marginals, basals and subapicals all about as long as dc.

Wing: Hyaline; veins very pale yellow, only Cu along discal vein a little darkened; RM stem vein thickened, anal cell pointed apically along anal vein; costal setulae all fine and pale. Haltere yellow with creamy white knob.

Legs: Entirely dull yellow with short pale setulae, only claws darkened; apicoventral seta of mid tibia present and longer than diameter of tibia at apex; legs without dilated segments or special modifications.

Abdomen:All tg with brown dorsal bands, leaving hind and lateral margins pale yellowish white; a few very fine setulae scattered thinly on all segments, but segment 6, which is as long as segment 5, has stronger and more numerous setulae.

Postabdomen: Very small and poorly sclerotized except for margins of hyp; ep poorly developed, but complete dorsally; cerc minute, translucent and very finely setulose; surs elongate, fused with ep and finely setulose; ph sclerotized but simple, almost tubular; ph apd very small and indistinct, only anterior apex sclerotized, gonites and ej apd could not be identified.

Female.

Very similar to male. All abdominal segments with midline sclerites. Postabdomen: tg 7 complete; st 8 sclerotized with small posteromedial lobe and setae ventrally; hypr small oval with fine setulae apically; cerc in proportion to adjacent structures rather large and setose apically.

Length: ơ and ^body 1.3 mm, wing 1.2 mm.

Variation: Presence and colour of scutal stripes variable, number of setulae on fr and acrs a little variable, otherwise all specimens examined are remarkably similar.

Type material examined: syntypes NAMIBIA: ơ “Klein Namaland, SW Africa, leg. Shultz (Humbolt)” ( ZMHB); 1^same data ( ZMHB) .

Other material examined: NAMIBIA: 1^Lüderitz District , Agate Beach, 10 km N Lüderitz, alt. 3 m, low coastal vegetated dunes, 18.ii.1974, M.E. & B.J. Irwin ( NMSA) ; 6^Skeleton Coast Park, Unjab R. Delta , 20°11'S: 13°13'E, 18–26.vii.1990, C.S. Roberts, pitfall traps ( NMWC) ; 1ơ Lüderitz District , [missing locality] 27°34'S: 15°28'E, 15–25.xi.1993, E. Marais, pitfall traps (in glycerine, NMWC) ; 1ơ 3^same data (in alcohol, NMNW) ; 1^Walvis Bay , alt. 5 m, 22°60'S: 14°28'E, 6.ix.2003, A. Freidberg ( TAUI) .

Genus Paraphaniosoma gen. n.

Type species: Aphaniosoma sexvittata Lamb, 1914 , here designated.

Etymology: From Latin par (like) and Aphaniosoma , the genus which it resembles.

Diagnosis: Separation of genus from Aphaniosoma is easy on basis of well-developed pra and post ia setae, scutal setulae in six or more rows between dc lines, only one strong dc and reduced or absent pvt.As in Aphaniosoma , strong apicoventral seta present on mid tibia, longer than diameter of tibia at apex.

Description:

Head: Margins of fr converge anteriorly; ocp concave, gena much narrower than height of eye; 1–5 orb reducing in size from back to front, all reclinate; 1 strong vti and 1 strong vte, pvt absent or minute and inconsistently present within a species; mouthparts normal; antenna as for the rest of the family, but arista 2-segmented.

Thorax:Appears somewhat elongated, a little less arched and usually with distinct longitudinal stripes on scutum. Chaetotaxy: 1 to 2 pprn, 1 ihu, 1 posthu, 2 ntpl, 1 pra, 1 sa, 1 pa, 1 post ia, 0+1–2 dc, scutal setulae in 4–8 rows with long prscut, 1 anepisternal at top of posterior border, 1 katepisternal at upper hind corner, no prpl; scut with basal and subapical pair.

Wing: Hyaline; crossveins and vein separating discal from basal cell translucent; R 4+5 and M 1+2 parallel or nearly so. Haltere without special modifications.

Legs: Normal, with no special modifications, mid tibia ventrally at apex with strong seta.

Abdomen: 6 visible tg in male, 7 or 8 in female; in both sexes, tg more or less uniformly short setulose.

Male postabdomen of the Aphaniosoma s. str. type, i.e., a small, partly internalized ep and markedly modified gonites and pregenital st. Female postabdomen with large tg 7, cerc separated from segment 8, which has a pair of sclerotized st plates.

Distribution: East Palaearctic, Afrotropical ( Fig. 70 ), Oriental,?Australasian. Most species are undescribed.

Ecology: Little is known about this genus, but the few records for Paraphaniosoma seem to be mainly from coastal and estuarine localities in hot tropical and subtropical climates.As more species undoubtedly will be discovered, this postulation could change.

Figures

Fig. 56. Krifomyia minutissima (Bezzi), ơ: (a, b) head, lateral (a) and anterior (b), scale bar = 0.4 mm; (c, d) hypopygium, lateral (c) and ventral (d), scale bar = 0.05 mm.

Fig. 57. Krifomyia minutissima (Bezzi), ^postabdomen: (a) ventral, (b) lateral. Scale bar = 0.15 mm.

Fig. 70. Distribution of Krifomyia gen. n. (•), Paraphaniosoma gen. n. (x), and Tethysimyia gen. n. ().