Herniosina calabra, Roháček, 2021

Rohacek, Jindrich, 2021, The Herniosina story continues in the Mediterranean: H. calabra sp. nov. from Calabria and H. erymantha Rohacek, new female from the Peloponnese (Diptera, Sphaeroceridae), ZooKeys 1061, pp. 165-190 : 165

Herniosina calabra sp. nov.

Figs 1 , 2 , 3-7 , 8-13 , 14 , 15-20

Type material.

Holotype ♂ labelled: "ITALY: W Calabria: Serre Calabresi Mts, Mongiana 2.4 km N, 38°32'05"N, 16°19'06"E ", "1000 m, 25.5.2018, in tufts of Juncus in alder forest, J. Roháček leg.", "Holotypus ♂ Herniosina calabra sp. n., J. Roháček det. 2021" (red label). The specimen is dry-mounted on pinned triangular card, intact (SMOC 06/001/2018-1, Fig. 1 ). Paratypes: 8♂ 12♀ with same locality labels but with "Paratypus [♂ or ♀], Herniosina calabra sp. n., J. Roháček det. 2021" yellow labels; 3♂ 3♀ paratypes with abdomen detached, genitalia dissected and all removed parts preserved in glycerine in coalesced plastic tube pinned below the specimen, 1♂ with wing removed for photography and also preserved in glycerine in pinned plastic tube below the specimen (SMOC 06/001/2018-2 - 06/001/2018-21).

Etymology.

The name of the new species is an adjective derived from Calabria (a region in southern Italy) where the type locality of the new species is situated.

Description.

Male (Fig. 1 ). Total body length 2.06-2.46 mm; general colour blackish brown with mostly very sparse dark greyish brown microtomentum, hence body relatively shining. Head blackish brown to brown, lightest on gena. Frons blackish brown posteriorly to brown anteriorly, sparsely microtomentose and largely shining. Occiput blackish brown to black with sparse dark greyish brown microtomentum. Orbits, interfrontalia (very narrow, poorly delimited) and ocellar triangle also greyish brown to dark grey (orbits) microtomentose and duller than rest of frons; frontal triangle relatively narrow, glabrous and shining. Cephalic chaetotaxy: pvt absent, only minute adpressed postocellar setulae behind ocellar triangle; occe distinctly shorter than occi, the latter ~ 2/3 length of vte; vti longest among frontal setae, vte and oc slightly shorter than vti; two strongly exclinate and closely situated ors, posterior longer than anterior and both distinctly shorter than oc; 4 to (usually) 5 relatively short ifr, 1 or 2 middle pairs slightly longer than others; 4 very minute ads inside and below ors; g weak, hardly longer than anterior peristomal seta; vi long, ~ as long as vti. Frontal lunule short, wide, basally brown as anterior margin of frons, apically darkened. Face with cavities below antennae dark brown to black, shining despite sparse greyish microtomentum; medial carina distinct although slightly elevated. Gena high, brown in anterior half, blackish brown posteriorly, sparsely grey microtomentose. Eye relatively small; its longest diameter ~ 1.9 × as long as smallest genal height. Antenna relatively long, black or 3rd segment blackish brown; 3rd segment distinctly tapered apically both in dorsal and lateral view, with cilia on apex as long as those longest on arista. Arista long, ~ 3.8 × as long as antenna, in basal 1/4 short ciliate, otherwise moderately long ciliate.

Thorax dark brown to black, mesonotum relatively shining because of sparse microtomentum, pleuron more densely microtomentose and duller (Fig. 1 ). Some sutures between pleural sclerites pale brown. Scutellum relatively large and long, rounded triangular, with dorsal surface flat and finely microsculptured, duller than mesonotum. Thoracic chaetotaxy: 2 hu but internal reduced to microseta; 2 postsutural dc, anterior short and weak (only 2 × longer than dc microsetae), posterior strong, ~ as long as or slightly shorter than basal sc; 8-10 rows of ac microsetae on suture; medial prescutellar ac pair somewhat prolonged and thickened but shorter than anterior dc; 2 strong sc, basal slightly longer than scutellum, apical (longest thoracic seta) ~ 1.5 × as long as basal; only 1 stpl because anterior stpl reduced to hardly discernible microseta.

Legs dark brown, coxae, trochanters, knees and tarsi brown to pale brown. f1 with sparse and relatively short setae in posterodorsal and posteroventral rows. f2 with a row of 4-6 curved but relatively short ventral setae in basal third (Fig. 5 ) in addition to the usual fine basal seta; t2 ventrally with a long row of small dense spines terminated by a strongly reduced va seta (markedly shorter than anteroapical seta), see Fig. 5 ; dorsal chaetotaxy of t2 as in congeners including relatively variable-in-length posterodorsal seta in apical fourth (Fig. 4 ). t2: mt2 = 1.91-2.02.

Wing (Fig. 2 ) with pale brownish membrane and pale brown to blackish brown veins. C hardly produced beyond apex of R4+5. R2+3 slightly sinuate to straight but apically distinctly upcurved to C; R4+5 sinuate but with apical half almost straight. Discal cell (dm) variable, relatively short to medium long, distally more or less tapered, usually with small process of M beyond dm-cu (venal fold of M continuing this process usually well visible); posterior outer corner of dm cell obtuse-angled, often with small to minute process of CuA1 beyond dm-cu, rarely rounded (1 specimen). A1 slightly sinuate; anal lobe well developed; alula narrow but not acute. Wing measurements: length 1.88-2.32 mm, width 0.77-0.97 mm, C-index = 0.87-1.17, rm\dm-cu: dm-cu = 2.87-3.67. Haltere with dirty yellow stem and dark brown knob.

Abdomen blackish brown to black, with only some postabdominal sclerites brown. Preabdominal terga (Figs 1 , 3 ) large, shining, with only scarce greyish microtomentum, mostly sparsely and shortly setose (but with setae more numerous than in H. erymantha ). T1+2 longest abdominal tergum. T4 distinctly longer than T3; T5 enlarged, although less than that of H. bequaerti , and postabdomen strongly down-curved (Fig. 3 ). T4 with 1 long seta in each posterior corner; T5 with 4-6 long setae at posterior margin (Fig. 3 ). Preabdominal sterna modified similarly as in relatives but differing in detail (Figs 3 , 6 ): S1+2 strongly bulging (Fig. 3 ) and anteromedially narrowly desclerotised, appearing incised (Fig. 6 ); S3 and S4 deeply anteriorly emarginate due to enlarged posterolateral lobes (Fig. 6 ); however, these lobes can be smaller (weakly developed) in the smallest specimens; S1+2, S3 and S4 with sparse setae, largely at posterior and lateral margins; S1+2 and S3 with only 1 medial pair of setae long; S4 with 2 pairs of long setae at posterior margin. S5 (Fig. 7 ) reduced (shortened) and transversely strip-shaped, with pale-pigmented setose lateral parts as in relatives but with darker medial part provided with a long, somewhat flattened (in lateral view slightly bent, see Figs 3 , 36 ) and deeply forked process carrying 2 or 3 setulae on apex of each digitiform lobe (Fig. 7 ). S6 and S7 coalesced to a complex asymmetrical sclerite hidden under T5 and S8 on left side of postabdomen, narrow ventrally and dorsally but laterally dilated and provided with several flat, keel-like internal lobes (Fig. 3 ). S8 as long as T5, somewhat tapered posteriorly, with 2 pairs of setulae and with a distinct slit left laterally, the margins of which terminate in 2 slender dark-pigmented digitiform lobes (see Fig. 3 ).

Genitalia. Epandrium (Figs 8 , 9 ) slightly longer but narrower than that of H. erymantha although also angular dorsolaterally (see Fig. 9 ), with a group of longer and stronger setae laterally and lateroventrally (posterior seta longest and most robust) and also dorsolaterally with 1 longer seta (as in H. bequaerti ). Anal fissure narrower than high (Fig. 9 ), suboval, thus more resembling that of H. bequaerti . Cerci fused with epandrium, each posteroventrally projecting in 2 processes most similar to those of H. erymantha : one (more anterior) robust, almost as long as gonostylus and distally slightly dilated and bearing 1 long seta in addition to series of microsetulae, the other (posterior and more medial) short, lengthwise conical, and bare (Figs 8 , 9 ). Anterior process of cercus differing from that of H. erymantha in having distal half distinctly bent out (see Fig. 9 ). Medandrium low, somewhat reduced and connected by long internal arms with gonostyli (Fig. 9 ), and posteromedially fused with cerci. Hypandrium with long (though shorter than in H. bequaerti and H. erymantha ) and slender anteromedial rod-like apodeme (Fig. 8 ). Gonostylus (Figs 8 , 9 , 10 ) sub-oblong in lateral view, most resembling that of H. erymantha but wider, posterodorsally bearing a distinct tooth (Fig. 10 ) and its slender dorsal internal process (visible on Fig. 9 ) short, slightly curved. Aedeagal complex (Figs 11-13 ) with large and long phallapodeme (as in both relatives) normally provided by large dorsal keel (as in H. bequaerti ). However, size of phallapodeme and its keel can be reduced in small specimens. Aedeagus most similar to that of H. bequaerti because distiphallus is short, with both lateral lobes and an unpaired ventral process short (Figs 11 , 12 ). Postgonite short and robust as that of H. bequaerti , differing mainly by robust and non-curved apex (Fig. 13 ). Phallophore resembling those of both relatives, anteriorly rod-like but dorsoventrally flattened (cf. Figs 11 and 12 ), posteriorly projecting ventrally and hence epiphallus-like. A minute, pale-pigmented ejacapodeme can be seen close to base of postgonites (Fig. 13 ).

Female (Fig. 14 ). Similar to male unless mentioned otherwise below. Total body length 2.10-2.78 mm. f2 ventrally without curved setae, with only 1 fine basal seta; t2 ventrally finely setulose and with 1 long va seta (Fig. 16 ); anteroapical seta and all setae on dorsal surface of t2 somewhat longer (Fig. 15 ) than in male. t2: mt2 = 1.63-1.95. Wing measurements: length 1.83-2.46 mm, width 0.77-1.05 mm, C-index = 0.87-1.06, rm\dm-cu: dm-cu = 2.85-3.75. Preabdominal terga shorter, more transverse and becoming narrower posteriorly, T1+2 widest and longest and with some microtomentum, while T3-T5 almost glabrous and strongly shining; T1+2-T4 similarly setose as in male; T5 unmodified, simply trapezoidal, with setae at posterior margin shorter. Preabdominal sterna unmodified, simple, sparsely and shortly setose and distinctly brownish grey microtomentose, subshiny. S1+2 smallest and dark pigmented only in posterior half; S3-S5 subequal in length but becoming wider posteriorly or S4 as broad as S5; S3 trapezoidal (wider posteriorly); S4 and S5 transversely sub-oblong; all these sclerites blackish brown and shining.

Postabdomen (Figs 17-19 ) telescopically retractable, basally (6th segment) markedly narrower than preabdomen at 5th segment. 6th segment (both T6 and S6) distinctly wider than 7th segment in contrast to those of H. bequaerti . T6 wide and short, transversely trapezoidal, with pale-pigmented anterior and (wider) posterior marginal stripe (Fig. 17 ), setose at lateral and posterior margins, with longest setae in posterior corners; T7 distinctly narrower than T6 and reaching farther onto lateral side (Fig. 19 ), with small unpigmented anteromedial area and setosity restricted to posterior margin (Fig. 17 ). T8 as long as T7 but dorsomedially narrowly depigmented and appearing divided into two dark sclerites (Fig. 17 ), in contrast to T8 of both H. bequaerti and H. erymantha . T10 transversely subtriangular (Fig. 17 ), shorter than those of H. bequaerti and H. erymantha ), pigmented (darkest anterolaterally) except for posterior corner, with a pair of long setae, some fine setulae and micropubescent on almost entire surface. S6 somewhat wider, shorter (more transverse), slightly paler and more setulose than S7 (Fig. 18 ). S7 dark-pigmented except for posterior marginal stripe and with 4 longer and several short setae at posterior margin. S8 (Figs 18 , 19 ) reduced, short but wider than those of H. bequaerti and H. erymantha , strikingly convex at anterior margin where densely micropubescent (cf. Fig. 19 ), otherwise with only 6-8 short setae. S10 reduced to distinctive transverse (in ventral view sinuous) sclerite, being medially depigmented (Fig. 18 ) but laterally blackish brown and posterodorsally rectangularly incised (Fig. 19 ), which is also visible in dorsal view (Fig. 17 ). S10 densely micropubescent and with a few setae including 1 long pair. Spermathecae 2+1 (Fig. 20 ) blackish brown, pyriform with conical bases, most resembling those of H. erymantha , sharing with the latter distally ringed conical bases, dark thickened apex and terminal parts of ducts of paired spermathecae connected rather far from their bodies; however, spermathecae of H. calabra are more robust, with wider basal conical parts. Cerci (Figs 17-19 ) more robust than those of H. bequaerti but much longer and narrower than those of H. erymantha , each bearing 1 dorsal preapical and 1 apical setae, both very long and sinuate, apart from other shorter setosity and dense micropubescence.

Remarks.

Herniosina calabra sp. nov. seems to be morphologically intermediate between H. bequaerti and H. erymantha . Although seemingly more similar to H. erymantha (smaller body size, shorter male T5 and S8, male S5 with deeply forked medial process, anterior process of male cercus long and robust, gonostylus ventrally rounded, not emarginate, spermathecae with conical basal part distally ringed) it is probably most closely related to H. bequaerti . Sister-species relationship of H. calabra and H. bequaerti seems to be particularly demonstrated by the following putative synapomorphies: very similar construction of the male aedeagal complex, including the short distiphallus (with both lateral lobes and unpaired ventral process short) and surprisingly similarly formed, short and robust postgonite. In the female postabdomen there is also a shared synapomorphy: the modified (posterodorsally more or less incised) lateral part of S10 (cf. Fig. 19 and Fig. 42 ).

The new species can be easily separated from all known congeners only by postabdominal characters. The most species-specific are as follows: the long, slender and deeply forked medial process of male S5 (Fig. 7 ); the male S8 with digitiform lobes on both sides of lateral slit (Fig. 3 ); the gonostylus with a posteromedial tooth (Fig. 10 ), the male cercus with anterior (more lateral) lobe with apex bent outwards (Fig. 9 ); the postgonite short and with robust apex (Fig. 13 ); the lateral part of female S10 dark-pigmented and with posterodorsal rectangular incision (Fig. 19 ). Moreover, the combination of female T8 medially narrowly depigmented with short T10 and relatively long slender cerci (see Fig. 17 ) is also very characteristic.

Biology.

The entire type series of H. calabra sp. nov. (21 specimens) was collected (aspirated by a pooter) in May under Juncus tufts (Fig. 22 ) growing under alder trees surrounding a small creek in a montane meadow (Fig. 21 ). The sphaerocerid community co-occurring with H. calabra in and under these tufts of rush (based on collected specimens) proved to be relatively rich and contained the following 15 species: Copromyzinae : Lotophila atra (Meigen, 1830) 2♂3♀, Sphaerocerinae : Sphaerocera curvipes Latreille, 1805 2♂2♀, Limosininae : Gigalimosina flaviceps (Zetterstedt, 1847) 2♂, Limosina silvatica (Meigen, 1830) 5♂3♀, Opacifrons coxata (Stenhammar, 1855) 1♀, Pteremis fenestralis ( Fallén, 1820), 4♂4♀, Pullimosina (Pullimosina) heteroneura (Haliday, 1836) 2♀, P. (P.) pullula (Zetterstedt, 1847) 3♀, P. (P.) vulgesta Roháček, 2001 1♂, Puncticorpus cribratum (Villeneuve, 1918) 1♂1♀, Spelobia clunipes (Meigen, 1830) 2♂, S. palmata (Richards, 1927) 1♀, S. talparum (Richards, 1927) 1♂1♀, S. sp. cf. talis Roháček, 1983 1♂ and Terrilimosina schmitzi (Duda, 1918) 1♀. This assemblage included largely saprophagous terricolous species (such as H. calabra , G. flaviceps , Limosina silvatica , Pteremis fenestralis , Pullimosina species, Puncticorpus cribratum , T. schmitzi ) but also a few microcavernicolous species ( Spelobia talparum , S. sp. cf. talis ) and some ubiquitous, predominantly coprophagous, species ( Lotophila atra , Sphaerocera curvipes , Spelobia clunipes ). The presence of the latter two groups indicates that there could also be some droppings of small mammals in the detritus. This is for the first time that a species of Herniosina has been found under tufts of a graminoid plant. However, rotting leaves of alder were also present under tufts of Juncus sp. examined (see Fig. 22 ), which indicate more resemblance to a leaf-litter association as known in most other Herniosina species (cf. Roháček 2016).

Distribution.

Hitherto only known from S. Italy (Calabria).

Figures

Figure 1. Herniosina calabra sp. nov., male laterally (holotype). Body length ~ 2.3 mm.

Figure 2. Herniosina calabra sp. nov., wing (male paratype). Wing length ~ 2.1 mm.

Figure 14. Herniosina calabra sp. nov., female laterally (paratype). Body length ~ 2.2 mm.

Figures 3 - 7. Herniosina calabra sp. nov. (male paratype). 3 Abdomen, laterally 4 mid tibia, dorsally 5 mid femur and tibia, anteriorly 6 preabdominal sterna, ventrally 7 S 5, ventrally. Abbreviations: ce - cercus, ep - epandrium, gs - gonostylus, S - sternum, T - tergum. Scale bars: 0.2 mm (3, 6); 0.3 mm (4, 5); 0.1 mm (7).

Figures 8 - 13. Herniosina calabra sp. nov. (male paratype). 8 Genitalia, laterally 9 external genitalia, caudally 10 gonostylus, laterally 11 aedeagus, dorsally 12 ditto, laterally 13 aedeagal complex, laterally. All scale bars 0.1 mm. Abbreviations: ce - cercus, dp - distiphallus, ea - ejacapodeme, ep - epandrium, gs - gonostylus, hy - hypandrium, ma - medandrium, pg - postgonite, pha - phallapodeme, pp - phallophore.

Figures 15 - 20. Herniosina calabra sp. nov., female paratypes. 15 Mid tibia, dorsally 16 ditto, anteriorly 17 postabdomen, dorsally 18 ditto, ventrally 19 ditto, laterally 20 spermathecae. Abbreviations: ce - cercus, S - sternum, T - tergum. Scale bars: 0.3 mm (15, 16); 0.1 mm (17 - 20).

Figures 33 - 41. Herniosina species, comparison of male characters. 33 H. bequaerti, S 5, ventrally, 34 same species, process of S 5, laterally 35 H. calabra sp. nov., S 5, ventrally 36 same species, process of S 5, laterally 37 H. erymantha, S 5, ventrally 38 same species, process of S 5, laterally 39 H. bequaerti, gonostylus, laterally 40 H. calabra sp. nov., gonostylus, laterally 41 H. erymantha, gonostylus, laterally. All scale bars 0.1 m.

Figures 42 - 44. Herniosina bequaerti (Villeneuve, 1917), female (Czech Republic: Bohemia). 42 Apex of postabdomen, laterally 43 ditto, dorsally 44 spermathecae. Scale bars: 0.1 mm (42, 43); 0.05 mm (44).

Figures 21 - 22. Habitat of Herniosina calabra sp. nov. 21 General view of the habitat in Serre Calabresi at Mongiana, alder trees and herbaceous undergrowth surrounding a small creek (25. v. 2018) 22 Juncus tuft, a microhabitat of the species.