Herniosina Rohacek , 1983

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 : 74-76

Taxon classification Animalia Diptera Sphaeroceridae

Genus Herniosina Rohacek, 1983

Herniosina Roháček, 1983: 18 (feminine). - Roháček 1983: 18-21 [diagnosis, key, revision of European species, illustr]; Roháček 1993: 186 [taxonomy, key, illustr.]; Roháček 1998: 487 [diagnosis in key, illustr.]; Roháček et al. 2001: 148 [catalog].

Herniosina Roháček, 1982: 221 [nomen nudum, phylogeny]. Type species. Leptocera ( Limosina ) Bequaerti Villeneuve, 1917, original designation.

Diagnosis.

pvt absent; 3-5 ifr; 2-5 minute ads inside and below ors; g small; 2 hu, the internal reduced to microseta; 2 postsutural dc, the anterior short; ac setulae in 6-10 rows on suture, the medial prescutellar ac pair more or less enlarged; 2 stpl, the anterior very small, hair-like or absent; scutellum large, rounded triangular to trapezoidal; t2 chaetotaxy as in Figs 16, 18, 57, 61, in male ventrally with a row of short spine-like setae and with reduced va, in female with anteroapical and va setae long (Fig. 18); male f2 ventrally with a row of more or less thickened setae (Figs 18, 54) in basal half; C not extended beyond apex of R4+5; R4+5 sinuate but apically almost straight; dm cell long and its posterior outer corner often rounded; alula relatively small and narrow; female postabdomen relatively (compared to preabdomen) narrow and telescopically retractile; male abdomen terminally strongly down-curved in consequence of enlarged T5 and S8 (Figs 1, 2, 15); male S1+2 protruding in a slightly (Figs 47, 51) to strongly convex bulge (Figs 1, 15); male S3 and S4 with anterior corners lobe-shaped (= sclerites anteromedially more or less deeply emarginate, Figs 17, 41); male S5 reduced, very transverse and band-shaped but posteromedially with a pair of projections (Figs 36, 65) which can be basally fused (Fig. 19) and/or prolonged (Fig. 11); epandrium with a row of robust long lateral setae at ventral margin and (usually) 1 longer dorsolateral seta (Figs 4, 28); male cerci modified to long, slender (usually doubled) processes (Figs 5, 21, 38, 50) below anal opening; gonostylus with a small (Fig. 5) to distinctive internal process (see Figs 22, 50); phallophore relatively long, anteriorly movably attached to dorsal side of distiphallus and projecting (epiphallus-like) posteroventrally (25, 26); distiphallus apically funnel-shaped and ventromedially projecting posteriorly in an unpaired process (Figs 26, 52); postgonite relatively robust, with small setulae only; ejacapodeme absent or strongly reduced (Fig. 53); female T8 dorsomedially compact, paler pigmented or divided; female T10 triangular, with a pair of long setae and some micropubescence; female S8 reduced to a small sclerite with a few setulae (Figs 8, 33, 62); female S10 short, strip-like, horseshoe- or V-shaped (Figs 33, 62, or medially divided into 2 sclerites (Fig. 8); female genital chamber membranous, lacking internal sclerites; spermathecae (2+1) pyriform (Fig. 10) to bulbous (Figs 59, 60); female cerci dark, long and slender, each with 2 long (apical and dorsopreapical) sinuous setae and a few shorter hairs.

Discussion.

The genus Herniosina can be identified by the key to European ( Roháček 1983) and/or Palaearctic Limosininae ( Roháček 1998). It seems to be best recognized by combination of apomorphic characters in the male abdomen and terminalia (postabdomen strongly down-curved, S1+2 bulging, S5 strongly reduced, cerci modified to peculiar projections, both distiphallus and phallophore projecting posteroventrally) and the plesiomorphic formation of the female postabdomen (relatively narrow and telescopic, no internal sclerites) having reduced S8. Although the diagnosis of the genus has to be somewhat modified (see above) with respect to the inclusion of the two new species described below, the genus remains to be a very compact monophyletic group if only Palaearctic species (reviewed here) are included.

However, Marshall (1987) described a very peculiar Limosinine species from USA (New Hampshire) and placed it as a tentative member of Herniosina on the basis of its bulging male S1+2 although this Herniosina voluminosa Marshall, 1987 differs very markedly from all other Herniosina species in many characters, lacking all other synapomorphies of the genus as originally delimited, including the modified male preabdominal sterna, reduced male S5, enlarged T5, projecting male cerci, form of phallophore, general shape of spermathecae etc. I have examined male and female paratypes of Herniosina voluminosa kindly donated by S. A. Marshall to SMOC (USA: New Hampshire: Coos Co., 3 mi. NE East Inlet Dam, Norton Pool, flight interception trap, 12.-24.vi.1986, 1♂, 25.vi.-9.vii.1986, 1♀, D. S. Chandler leg.) and found that the male S1+2 of Herniosina voluminosa is differently (posteromedially) protruding and somewhat bilobed (see also Marshall 1987: Fig. 1) suggesting that this modification of S1+2 evolved independently and hence cannot be a synapomorphy of this Nearctic species and Herniosina s. str. species. Also its extremely enlarged aedeagal complex (with enormous distiphallus, phallophore and postgonite being several times larger than epandrium) and quite differently formed female terminalia (with S8 large and transverse, internal spectacles-shaped sclerite developed, spermathecae elongate and transversely wrinkled and T10 fused with base of cerci) clearly demonstrate that these taxa cannot be congeneric. Inasmuch as it seems that both known Apteromyia species (cf. Marshall and Roháček 1982) are apparently more closely allied to the Palaearctic species of Herniosina than is Herniosina voluminosa (see below) the latter species is excluded from Herniosina here to render the genus monophyletic. It is therefore suggested to establish a new genus for the removed Herniosina voluminosa in the near future.

When describing the genus, Roháček (1982: 221, 1983: 18) placed Herniosina in the Limosina genera-group and discussed its affinity as being either a sister-group of the genus Apteromyia Vimmer, 1929 or sister-group of a clade comprising besides the latter genus also two other members of the Limosina genera-group, viz. Limosina Macquart, 1835 and Gigalimosina Roháček, 1983. Subsequently, Marshall & Roháček (1982) considered the former hypothesis to be more probable pointing out similarly modified (projecting) male cercus and setosity of epandrium in the Nearctic species Apteromyia newtoni Marshall & Roháček, 1982 and Herniosina species. Based on the present study the relationships of Herniosina and Apteromyia is supported by four supposedly synapomorphic characters (all in the male genitalia): epandrium with a series of robust ventral lateral setae; male cerci modified to compact processes below anal fissure, distiphallus with unpaired ventromedial lobe projecting posteriorly; phallophore anteriorly slender and elongately projecting, movably attached to dorsal side of distiphallus.

Species included.

Herniosina bequaerti (Villeneuve, 1917), Herniosina erymantha sp. n. (described here), Herniosina horrida ( Roháček, 1978), Herniosina pollex Roháček, 1993 and Herniosina hamata sp. n. (described here). Hitherto, Herniosina species are only known from the W. Palaearctic area, including that recorded as Herniosina sp. cf. horrida from Israel by Papp and Roháček (1988). The latter record, based on two females only, may belong to Herniosina horrida or, more probably, to an additional unnamed species but its description is pending further study of (hitherto unknown) males.