Herniosina hamata, Rohacek, Jindrich, 2016

Rohacek, Jindrich, 2016, Herniosina Rohacek: revised concept, two new species, new key and atlas of male and female terminalia (Diptera, Sphaeroceridae), ZooKeys 609, pp. 69-106 : 87-91

Taxon classification Animalia Diptera Sphaeroceridae

Herniosina hamata sp. n. Figs 47-48, 49-56, 57-65

Type material.

Holotype ♂ labelled: "C CYPRUS: Troodos Mts., Pedoulas env., J. Roháček leg.", "sweeping over ruderal vegetation, 12.4.2002", "Holotypus ♂ Herniosina hamata sp. n., J. Roháček det. 2016" (red label). The specimen (see Fig. 47) is intact except for the left wing being detached for photography (Fig. 48) and preserved in glycerine in a coalesced plastic tube pinned below the specimen (SMOC). Paratypes: C CYPRUS: Troodos Mts, Troodos 2 km NE, 1700 m, sweeping vegetation along small creek, 11.iv.2002, 1♂8♀ (1♂1♀ genit. prep.); Troodos Mts, Troodos env., 1800 m, sweeping vegetation along spring, 11.iv.2002, 1♀ (genit. prep.); Troodos Mts, Kakopetria 2 km SW, sweeping vegetation along brook, 11.iv.2002, 1♀ (genit. prep.); Pano Platres env., Caledonia Falls, on decayed leaves by stream, 12.iv.2002, 1♂ (genit. prep.); W CYPRUS: Troodos Mts, Kykko Monastery 4 km E, sweeping undergrowth of pine forest, 12.iv.2002, 1♀, all J. Roháček leg. (SMOC). Paratypes labelled "Paratypus ♂ or ♀, Herniosina hamata sp. n., J. Roháček det. 2016" (yellow label) in addittion to their locality labels.

Etymology.

The new species is named by the adjective " hamata " to reflect its hook-like posteromedial (internal) process of the gonostylus (hamatus = Lat. provided with hooks).

Description.

Male (Fig. 47). Total body length 1.94-2.38 mm; general colour blackish brown with relatively sparse dark greyish brown microtomentum, subshining (thorax) to shining (abdomen). Head blackish brown to brown, much higher than long (Fig. 47). Frons brown anteriorly, dark brown to blackish posteriorly, sparsely microtomentose. Occiput blackish brown with microtomentum denser. Orbits, interfrontalia and ocellar triangle sparsely greyish brown microtomentose; frontal triangle poorly delimited, relatively wide, anteriorly acute and more shining than rest of frons. Cephalic chaetotaxy: pvt absent, only minute divergent postocellar setulae behind ocellar triangle; occe and occi subequal (or occi slightly longer) and about half length of vti; vti robust and longest of frontal bristles; vte and oc slightly to distinctly shorter than vti; 2 ors, posterior longer than anterior but distinctly shorter than oc; 3-4 relatively short ifr, all subequal or foremost shorter, if 4 ifr present, the foremost reduced to small setula; 3-6 very minute ads inside and below ors; g weak, hardly longer than anterior peristomal setula; vi as long as or longer than vte but thinner. Frontal lunule short and wide, brown and greyish brown microtomentose. Facial cavities below antennae dark brown, relatively shining; medial carina poorly developed but distinct. Gena brown (lightest on virbrissal angle), posteriorly dark brown, greyish brown microtomentose. Eye relatively small; its longest diameter about 2.2 times as long as smallest genal height. Antenna dark brown, relatively long; its 3rd segment distinctly tapered apically, both in lateral and dorsal view. Arista long, about 4 times as long as antenna, relatively long and densely ciliate.

Thorax blackish brown and dark greyish brown microtomentose, mesonotum subshining, pleuron with denser microtomentum and dull. Suturae between pleural sclerites pale brown. Scutellum large, relatively long and flat, rounded trapezoidal. Thoracic chaetotaxy: 2 hu, internal reduced to microseta; 2 postsutural dc, anterior short (only 2-3 times as long as dc microsetae), posterior as long as or slightly longer than basal sc; 10 dense rows of ac microsetae on suture; medial prescutellar ac pair prolonged, about as long as anterior dc but finer; 2 long sc, basal about as long as or slightly longer than scutellum, apical about 1.7 times as long as basal; 1-2 stpl, anterior (if present) reduced to very minute pale setula.

Legs brown, coxae, trochanters, knees and tarsi paler brown to ochreous. f2 with a doubled row of curved but relatively short ventral setae in basal half (Fig. 54); t2 ventrally with a long row of small dense spines, very reduced va seta and 1 distinct anteroapical seta (Fig. 54); dorsal chaetotaxy of t2 as in Fig. 57, with posterodorsal seta in apical fourth long. t2: mt2 = 1.85-1.89.

Wing (Fig. 48) with pale brown membrane and yellowish brown to dark brown veins. C ending at or very slightly produced beyond apex of R4+5. R2+3 very slightly sinuate and also apically slightly upcurved to C; R4+5 distinctly sinuate but its apical half nearly straight. Discal cell (dm) rather long, distally tapered, with small process of M beyond dm-cu; posterior outer corner of dm cell varies from angular with a remnant of CuA1 to rounded and lacking the latter. A1 slightly sinuate; anal lobe large, well developed; alula narrow, apically rounded. Wing measurements: length 2.06-2.24 mm, width 0.85-0-91 mm, C-index = 0.97-1.03, rm\dm-cu: dm-cu = 3.64-4.50. Haltere with yellowish brown to ochreous yellow stem and dark brown knob.

Abdomen blackish brown dorsally, brown ventrally. Preabdominal terga large, glabrous and shining because of reduced and sparse greyish microtomentum (restricted to T1+2 and bases of T3-T5), sparsely setose but with more setae on disc than those of relatives. T5 enlarged but not so prolonged as in Herniosina bequaerti . Preabdominal sterna S1+2-S4 (Fig. 51) also shining but distinctly more setose than in all congeners. S1+2 with ventral bulge reduced (Fig. 47, arrow) but somewhat protruding in the middle; S3 and S4 (Fig. 51) anteromedially emarginate and with characteristic lateral dark pigmentation. S5 (Fig. 65) very shortened, reduced to a transverse strip-like and largely weakly sclerotized and pale-pigmented sclerite with only partly darker and setose lateral parts (with 5-6 setae on each side) and posteromedially provided with a pair of small digitiform processes arising from a common base. S6+7 and S8 asymmetrical on left side of down-curved postabdomen, most similar to those of Herniosina pollex , thus the latter relatively short.

Genitalia. Epandrium (Figs 49, 50) of medium length but comparatively broad (wider than high), with a series of longer and stronger setae mainly lateroventrally (posterior longest); also laterodorsally with 1 longer seta. Anal fissure relatively small, suboval, slightly wider than in Herniosina pollex . Cerci fused with epandrium, each projecting ventrally in single (medial process absent) long, digitiform, terminally somewhat dilated process with blunt apex, basally carrying 1 long seta (Figs 49, 50). Medandrium fused with cerci medially and connected by long internal arms with gonostyli (Fig. 50). Hypandrium with long anteromedial rod-like apodeme, more robust than that of Herniosina pollex . Gonostylus (Figs 49, 50, 56) dissimilar to those of all congeners, with pointed anteroventral corner and long anterior seta as in most relatives but ventrally externally with rounded and setose lobe and posteroventrally with distinctive, robust, dark, hook-like internal process. Aedeagal complex (Figs 52, 53, 55). Phallapodeme large and long, laterally flattened due to very large (high) dorsal and ventral keel. Aedeagus with peculiar distiphallus, most different from those of relatives because of small lateral lobes (Fig. 53), long ventromedial, posteriorly far projecting lobe (Fig. 52) and relatively short but broad funnel-shaped apex (Fig. 53); also phallophore distinctive, with short and more robust anterior part and small, slender, pointed posterior epiphallus-like projection (Fig. 52); postgonite relatively short and robust (Fig. 55), with expanded posterior lobe proximally and distinctly bent and pointed apex distally. Ejacapodeme reduced to very minute sclerite (see Fig. 53) hidden in posterior fissure of phallophore.

Female. Similar to male unless mentioned otherwise below. Total body length 1.90-2.54 mm. Gena sometimes paler, reddish brown anteriorly and brown posteriorly. f2 ventrally without curved setae, simply setulose; t2 ventrally only finely setulose and with 1 long va seta; also anteroapical seta somewhat longer (Fig. 61). t2: mt2 = 1.65-1.85. Wing measurements: length 1.79-2.28 mm, width 0.73-0.95 mm, C-index = 0.92-1.13, rm\dm-cu: dm-cu = 3.41-4.40. Preabdominal terga shorter, more transverse and becoming narrower posteriorly, similarly setose as in male. Preabdominal sterna unmodified, simple, sparsely and shortly setose. S1+2 smallest and dark pigmented only posteriorly (one fourth to half); S3-S5 becoming wider posteriorly, S3 and S4 trapezoidal (wider posteriorly); S5 transversely sub-oblong, wider but distinctly shorter than S4; all these sclerites dark brown and shining.

Postabdomen (Figs 58, 62, 63) telescopically retractible but broader than in relatives, particularly as regards 7th and 8th segments. T6 wide and short, transversely oblong, paler brown than T7 (Fig. 58); T7 hardly narrower than T6 but reaching farther onto lateral side (Fig. 63), sparsely setose only at posterior margin. T8 medially not only depigmented but distinctly divided in two dark sclerites (Fig. 58). T10 subtriangular, distinctly wider than long (shorter than that of Herniosina pollex ), pale-pigmented only in anterior half and dorsally with a pair of longer setae arising far each from other (Fig. 58). S6 slightly wider, paler and more densely setulose than S7, shorter and more transverse (Fig. 62) than in all relatives. S7 dark-pigmented except for small anteromedial area (Fig. 62) and with 4 longer and several short setae at posterior margin. S8 (Figs 62, 64) narrow, of highly distinctive, posteriorly widened shape, having large subcircular to ovoid membranous (sometimes posteriorly open) window in posterior half and only 4-8 fine setulae at posterior margin. S10 reduced to short, broadly V-shaped microtomentose and setose sclerite (Fig. 62). Spermathecae 2+1 (Figs 59, 60) blackish brown, bulbous (onion-shaped), without robust basal conical parts; terminal parts of ducts very slender and pale-pigmented. Cerci (Fig. 58, 63) distinctly wider and shorter than in all relatives (including Herniosina pollex ), with 1 dorsal preapical and 1 apical seta long sinuate as in congeners but the latter inserted somewhat subapically (see Fig. 63).

Discussion.

Herniosina hamata sp. n. is a distinctive species, markedly different from all other species of the genus in the structures of the male and female terminalia. It is characterized by an interesting combination of plesiomorphic (e.g. reduced bulge on male S1+2; more setose male preabdominal sclerites; male S5 with a pair small medial projections; male cercus projecting in single process; gonostylus without dorsal internal projection; ejacapodeme minute but present; spermathecae simple, bulbous, without conical basal part) and distinctly derived autapomorphic features (gonostylus with hook-like posteroventral internal process; phallapodeme dorsoventrally dilated by both dorsal and ventral keel; distiphallus with long posteriorly projecting medial lobe; female postabdominal segments widened; female T8 dorsomedially divided; female S8 with „window“; cercus robust and with subapically inserted apical seta). Herniosina hamata sp. n. most resembles Herniosina pollex but the shared characters proved to be all plesiomorphic (male S1+2 with bulge reduced; male S5 with a pair of small medial projections; shorter male T5 and S8) and do not demonstrate their sister-species relationships. Indeed, the set of plesiomorphies of Herniosina hamata sp. n. indicate that it could represent a sister-taxon to its four remaining congeners (see discussion of intrageneric relationships below).

Biology.

Almost all type specimens were swept from low (and sparse) vegetation growing on layers of wet rotten plant debris. This is also true for the holotype being netted from „ruderal“ vegetation on a pile of decayed leaves in a shaded ditch by a road. The longest series (9 specimens) was taken by netting over shooting plants on the wet shores of a small creek covered with decayed remnants of vegetation shortly after the snow melted (Fig. 66); also the habitat with decayed leaves close to a montane stream (Fig. 67) near the Caledonia Falls can be considered typical for the species. The altitudes of localities (all in Troodos Mts) range from about 900 m (Kakopetria env) to 1800 m (Troodos, close to Olympos Mt.) and all specimens were collected on 11-12 April.

Distribution.

Hitherto only known from Cyprus (Troodos Mts); first recorded as unnamed species of Herniosina by Roháček (2004).