Herniosina erymantha Rohacek , 2016

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 erymantha Rohacek, 2016

Figs 23 , 24 , 25-30

Herniosina erymantha Roháček, 2016: 80 [male only, phylogenetic notes, illustr.]. Type locality: Greece, Peloponnese, Alepochori 0.5 km SE.

Type material.

Holotype ♂ labelled: "GREECE: NW Peloponnese: Alepochori 0.5 km SE 37°58'57"N, 21°48'10"E ", "590 m, 27.5.2015, sifting leaves under Platanus , J. Roháček leg.", "Holotypus ♂ Herniosina erymantha sp. n., J. Roháček det. 2016" (red label). The specimen is dry-mounted on pinned triangular card, with left wing and abdomen detached, genitalia dissected and all removed parts preserved in glycerine in coalesced plastic tube pinned below the specimen (SMOC).

Other material examined.

Greece: SW Peloponnese: Taygetos Mts, Nedousa 0.5 km W, 37°08'35"N, 22°12'17"E, 390 m, sweeping riverside vegetation, 5.x.2017, 2♂ (1♂ genit. prep.); Taygetos Mts , Artemisia 1 km E, 37°05'47"N, 22°14'27"E, 655 m, sweeping vegetation along brook, 7.x.2017, 1♂, 9.x.2017, 1♀ (genit. prep.); Taygetos Mts , Saidona 1.5 km NE, 36°53'16"N, 22°17'59"E, 820 m, sweeping vegetation along brook, 8.x.2017, 1♂ (genit. prep.), all J. Roháček leg. (SMOC) .

Supplementary description.

Male (Fig. 23 ). Total body length 1.79-2.46 mm. Head. Cephalic chaetotaxy: 3 or 4 relatively short ifr, subequal in length or the middle pair longer. Gena high, usually reddish-brown only anteriorly, sometimes on most of genal surface. Third antennal segment with ciliation on apex as long as longest cilia on arista.

Thorax. Scutellum relatively large and long (1.5 ~ as wide as long), rounded triangular, with dense fine microsculpture on flat dorsal surface. Thoracic chaetotaxy: 1 or 2 stpl, posterior long, anterior reduced to microseta or absent.

Legs. f2 with a long row of 6-8 curved but relatively short ventral setae in basal half to two-thirds. t2: mt2 = 1.83-1.90.

Wing. Discal cell (dm) variable, relatively short to medium long, distally usually less tapered than in most relatives, with small process of M beyond dm-cu being continued by a venal fold; posterior outer corner of dm obtuse-angled to rounded, sometimes with small remnant of CuA1. Wing measurements: length 1.87-2.38 mm, width 0.77-1.01 mm, C-index = 0.88-1.09, rm\dm-cu: dm-cu = 2.62-3.15.

Abdomen. Male S5 (Fig. 37 ) with medial forked process in lateral view knob-like, distinctly shorter but much more robust (Fig. 38 ) than that of H. calabra (Fig. 36 ).

Genitalia. Epandrium besides a group of longer and stronger setae laterally and lateroventrally usually also with 1 longer dorsolateral seta which can sometimes be reduced (as is in the holotype, see Roháček 2016: figs 20, 21). Gonostylus (Fig. 41 ) with posterodorsal corner broadly rounded, never tooth-like and projecting.

Female (Fig. 24 ). Similar to male unless mentioned otherwise. Total body length 2.06-2.52 mm. f2 ventrally without thicker curved setae, simply setose including 1 long fine basal seta; also t2 ventrally finely setulose but with 1 long va seta and anteroapical seta longer than in male (Fig. 25 ) and longer than in female C. calabra ; setae on dorsal surface of t2 (Fig. 26 ) also longer than in male, particularly as regards distal posterodorsal seta. t2: mt2 = 1.71-1.80. Wing measurements: length 1.91-2.34 mm, width 0.83-0.99 mm, C-index = 0.94-1.07, rm\dm-cu: dm-cu = 2.92-3.46. Preabdominal terga shorter, more transverse and becoming narrower posteriorly, similarly setose as in male. T1+2 widest and longest, covered by sparse but distinct microtomentum apart from posterior marginal stripe; T3-T5 subequal in length, strongly shining because T3 and T4 are glabrous and T5 has microtomentum reduced. Preabdominal sterna unmodified, simple, sparsely and shortly setose and distinctly brownish grey microtomentose, hence less shining than in male. S1+2 smallest, less transverse than S3-S5, darker pigmented only in posterior two-thirds (one fourth to half); S3 and S4 becoming slightly wider posteriorly (S4 largest) and both slightly trapezoidal (wider posteriorly); S5 transversely suboblong, somewhat narrower and shorter than S4; all these sclerites dark brown.

Postabdomen (Figs 27-29 ) telescopically retractable but broader than in H. bequaerti or H. calabra , particularly as regards 7th and 8th segments when compared with width of 5th abdominal segment. T6 wide and short, transversely oblong, with pale-pigmented posterior marginal stripe (Fig. 27 ), sparsely setose at posterior and lateral margin, with 1 long seta in each posterior corner; T7 only slightly narrower than T6 (Fig. 27 ) but reaching farther onto lateral side (Fig. 29 ), sparsely setose only at posterior margin and with very narrowly unpigmented posterior margin. T8 shorter and narrower than T7, all dark-pigmented or only narrowly paler at posterior margin medially (Fig. 27 ). T10 shortly pentagonal, rounded laterally, less transverse than that of H. calabra but shorter than that of H. bequaerti , pale-pigmented only anteriorly and laterally, and dorsally with a pair of long setae, a few fine setulae and entirely covered by micropubescence (Fig. 27 ). S6 wider, more transverse and more densely setulose than S7, dark-pigmented except for posterior margin (Fig. 28 ), with 4 or 6 long posterior setae. S7 also dark but with narrowly unpigmented anterior margin (Fig. 28 ) and with 4 long (those in medial pair close to each other) setae in addition to sparse short setae in posterior half. S8 (Figs 28 , 29 ) small, narrower than that of H. calabra , having posterior half tapered, with several fine setae (4 longer) and distinctive micropubescence, particularly anteromedially. S10 reduced to short, V-shaped, micropubescent and setose sclerite being medially depigmented to interrupted (Fig. 28 ), with lateral pigmented parts simple (Fig. 29 ) in contrast to those of H. calabra . Spermathecae 2+1 (Fig. 30 ) blackish brown, elongate pyriform, most resembling those of H. calabra but with basal conical parts narrower. Cerci (Figs 27-29 ) markedly different from those of both H. calabra and H. bequaerti , unusually short and robust (more so than in H. hamata Roháček, 2016), apically conical and dorsoventrally somewhat flattened, each with 1 dorsal preapical and 1 apical seta long sinuate and 1 ventral preapical seta curved (apart form a number of shorter setae), and with dense micropubescence.

Remarks.

Herniosina erymantha sp. nov. has only been known from the male holotype ( Roháček 2016). A series of specimens recorded here enabled the description of the male to be supplemented and to add the first description of the female. As mentioned above (see Remarks under H. calabra ), H. erymantha seems to be most closely allied to the sister-pair H. bequaerti - H. calabra . This relationship can now also be confirmed by the female postabdominal characters, including the similar formation of female S8 and, particularly, by the medially depigmented (to almost interrupted) S10 (cf. Fig. 28 ).

On the other hand, female H. erymantha can be easily distinguished from females of both its relatives (and also from all other congeners) by the unusually robust cerci (Fig. 27 ) and the detailed shape of S8 and S10 (Fig. 28 ).

Biology.

Almost all newly obtained specimens of H. erymantha were swept from above decaying leaf-litter and sparse vegetation under Platanus trees in valleys of montane brooks in the Taygetos Mts (Figs 31 , 32 ), usually mostly in humid places (shores of brooks, springs). Because the holotype was sifted from dead leaves of Platanus in a similar montane habitat in the Erimanthos Mts (see Roháček 2016) it is very probable that its larvae develop in this microhabitat. Adults are now known to occur in May ( Roháček 2016) and October (present data).

Distribution.

Hitherto only known from Greece: Peloponnese.

Figures

Figure 23. Herniosina erymantha Rohacek, 2016, male laterally (Greece: Peloponnese). Body length ~ 2.4 mm.

Figure 24. Herniosina erymantha Rohacek, 2016, female laterally, with a mite on thoracic pleuron (Greece: Peloponnese). Body length ~ 2.2 mm.

Figures 25 - 30. Herniosina erymantha Rohacek, 2016, female (Greece: Peloponnese). 25 Mid tibia, anteriorly 26 Ditto, dorsally 27 postabdomen, dorsally 28 ditto, ventrally, 29 ditto, laterally, 30 spermathecae. Scale bars: 0.3 mm (25, 26); 0.1 mm (27 - 30).

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 31 - 32. Habitat of Herniosina erymantha Rohacek, 2016. 31 valley of montane brook surrounded by Platanus trees near Nedousa village in Taygetos Mts (Greece: Peloponnese) (5. x. 2017) 32 Platanus growth near brook near Artemisia village in Taygetos Mts with the Czech dipterists J. Stary (on left) and M. Vala (on right) in foreground (9. x. 2017).