Reikosiella (Hirticauda) rostrata (Ruschka) Ruschka, 2013

Fusu, Lucian, 2013, A revision of the Palaearctic species of Reikosiella (Hirticauda) (Hymenoptera, Eupelmidae), Zootaxa 3636 (1), pp. 1-34 : 23-27

8. Reikosiella (Hirticauda) rostrata (Ruschka) comb. nov.

( Figs 1 , 10 , 17, 38, 41–42, 45–48)

Eupelmus rostratus Ruschka, 1921: 291 –293, Austria (Lectotype Ƥ, NHMW, present designation); Nikol’skaya, 1952: 497 (keyed); Erdỏs, 1960: 214, 219, 229 (keyed, biology, distribution); Suciu, 1961: 99, 101 (biology, description, figured); Bouček, 1968: 238 (distribution); Bouček, 1977: 64 (distribution, biology); Herting, 1977: 106–107 (catalogued); Trjapitzin, 1978: 232 (keyed); Kalina, 1988: 23, 25 (keyed, compared with Eupelmus bolivari Kalina ); Kalina, 1989: 111 (catalogued); Yang, 1996: 217, 326 (compared with Eupelmus curvator Yang ); Askew, 1999: 155 (distribution); Askew et al. 2001: 31 (distribution); Vidal S. 2001: 59 (distribution, catalogued); Melika et al., 2002: 78 (biology, distribution); Andriescu, 2003: 198 (distribution), Askew & Nieves-Aldrey, 2004: 37 (variability, identification needs confirmation); Moldovan, 2007: 269 (catalogued); Fusu 2008: 824, 826, 828 (cytogenetics, systematics).

Eupelmus (Eupelmus) rostratus: Askew & Nieves-Aldrey, 2000: 54 (keyed, distribution).

SPECIMENS EXAMINED. AUSTRIA: Lectotype Ƥ of Eupelmus rostratus (present designation): cerr./ april.; Eupelmus / rostratus Ƥ/ Ruschka Type; Eupelmus rostratus Rusch. / Lectotypus Ƥ/ Bouček det. 1966 [red label]. Paralectotypes 5Ƥ 13, all with the red label Eupelmus rostratus Ruschka 1921 / Paralectotypus Ƥ [or 3]/ Bouček det. 1966: 1Ƥ, Eupelmus / rostratus / Ruschka cotype. 1Ƥ, Hartigi / Brühl/ apr. 80; Eupelmus / rostratus / det. Ruschka. 1Ƥ, Eupelmus / rostratus / Ruschka cotype. 1Ƥ, cerr./april; Eupelmus / rostratus / det. Ruschka. 13, coriar/ marz; Eupelmus / rostratus 3/ Ruschka Type. 1Ƥ, cer-/ris; Eupelmus / rostratus / Ruschka cotype (NHMW). ROMANIA: 1Ƥ, Botoşani county, Leorda, from dead branches of Cornus mas , 20.IV.2006, L. Fusu (AICF). 1Ƥ, Iaşi, Bucium [forest], 06.VI.1956, I. Andriescu (ANCO). GREECE: Kerkini Lake N Park, Angistron Mts, glade in temperate forest, 3.V.2010, N 41˚19’33.0” E 23˚24’22.6”, 843 m, L. Fusu, O. Popovici & G. Ramel (AICF). HUNGARY: 1Ƥ, Izbég, 22.iv.1931, ex. Aphelonyx cerricola, G. Szelényi (HNHM). 1Ƥ, Tarján forest, 27.v.1959, road and open wood, J. B. Szabó [in Hungarian] (Hedqvist collection in BMNH). FRANCE: 13, Forêt de Chatillon, 1.vi.1974, J. Barbier (MNHN). THE NETHERLANDS: 1Ƥ, Hilversum, v.1963, ex. Biorhiza pallida, J. Troelstra (CNC).

DESCRIPTION. FEMALE. Length 1.9–3 mm. Head ( Fig. 1 ) with bright metallic green lustre, though with some bluish hue under some angles on scrobal depression and gena, sometimes with a bronze and coppery transverse band in front of anterior ocellus and similarly colored lower parascrobal region, to quite dark green with lower parascrobal region and frontovertex with purple, red, and golden-green lustres and a bronze hue on gena; maxillary palpi light-brown, labial palpi dirty-yellow. Antenna usually with scape yellow except slightly darkened dorsally at apex (light brown with brown dorsal margin and faint metallic lustre in one melanic specimen from The Netherlands); pedicel and flagellum brown with a faint metallic lustre (Fig. 17). Mesosoma ( Fig. 10 ) primarily brownish dorsally and ventrally, and yellow laterally; pronotum dorsally with faint coppery and bluish-green lustres under some angles of light to dark brown with metallic green lustre; mesoscutum with metallic lustre except yellowish-brown on sides of lateral lobes, convex median lobe bluish-green, lateral lobes green with bronze and median depressed area purple with blue in anterior half becoming dark brown with faint metallic lustre posteriorly; tegula brownish; scutellum dark bluish-green dorsally, sometimes with a violet median spot and brighter goldengreen on posteriorly sloping surface, axillae mostly yellowish to dark yellowish-brown with faint purple shine, contrasting at least slightly and usually strongly with scutellum; dorsellum mostly brown; propodeum with dark green and violet lustres on callar regions; prepectus light brown and contrasting with completely yellow acropleuron or prepectus, and acropleuron concolorous light to dark brown; mesepisternum dark brown. Fore wing with brown venation except median part of submarginal vein whitish; disc unevenly infuscate starting from parastigma and at base of basal cell, with three darker, fuzzy areas: one behind parastigma and basal third of marginal vein continuing along basal fold, one behind stigmal vein and apical third of marginal vein extending to median fold, and one distad stigmal vein at anterodistal angle of wing (Fig. 17, 45). In lighter specimens, legs brownish-yellow except coxae dark brown, the hind coxa darkest and with anterior coxa yellowish apically and middle coxa ventrally, and with following dark brown areas: fore leg with darker dorsal and posterior surfaces of femur, mid leg with a brown stripe in distal half of dorsal surface of femur and tibia slightly darkened in basal half, hind leg with femur mostly brown except a wide pale stripe dorsally and at base of ventral surface, and tibia with longitudinal brown stripes on anterior and posterior surfaces and with pale base and apex; last tarsomeres dark brown. In darker specimens mid and hind femora almost completely darkened except ventrally and tibiae pale only apically. Metasoma with Mt1 brownish, Mt2 and Mt3 translucent, whitish, except Mt2 with pale brown base, Mt4–Mt8 dark brown with faint multicolored metallic lustres under some angles of light; in darker specimens metasoma less conspicuously whitish basally but at least paler ventrobasally. Ovipositor sheath with a variably wide yellowish median ring, dark brown basally and apically.

Head with frontovertex polished with imperceptible coriaceous sculpture and sparse setiferous pinprick-like punctures, imbricate-alutaceous to coriaceous toward occipital area and upper limit of scrobal depression; lower face and gena alutaceous with area near malar sulcus smoother; scrobal depression shallow and wide, trapezoidal, imperceptibly merging into frons, in lateral view with slightly angular lower parascrobal region, polished except strongly imbricate-alutaceous on upper angles adjacent to orbit ( Figs 1 , 46 ); setation inconspicuous, dark and semierect on frontovertex, white on lower face and lower parascrobal region. Frontovertex 0.45–0.5× head width, with ocelli arranged in a right triangle. Eye microsetose with setae about as long as an ommatidium. Toruli with upper margin in line with lower orbit. Scape strongly curved in dorsal view, in outer view about 3.2–3.5× as long as wide, with an extremely narrow ventral lamina apically, wider mesally with dorsal margin evenly curved and ventral margin sinuously narrowed toward apex; in lateral view pedicel about 2× as long as wide, F1 quadrate, F2 1.6–1.8× as long as wide, and following segments all longer than wide, gradually shortened and broadened toward clava; clava 2.3–2.4× as long as wide, slightly longer than two and a half apical funiculars ( Fig. 48 ); pedicel plus flagellum 1.7–1.8× HW. Relative measurements: HW 28–44, FV 13.5–20, HL 16–23, HH 14–37, EL 13–21, EW 11–18, MS 9–13, LOL 3–5, OOL 3–4, POL 6–7.5, MPOD 2–3.5, SL 16–26, SW 5–7.5.

Pronotum divided medially, with alutaceous to imbricate-alutaceous sculpture and numerous long setae, mostly grouped in a line along posterior margin; mesoscutum with convex anterior lobe reticulate anteriorly and becoming imbricate-coriaceous toward median depressed area, with numerous translucent setae, lateral lobes sharply carinate in posterior third, finely alutaceous to coriaceous dorsally (mesh size very small) and becoming imbricate-alutaceous on sides, with numerous translucent setae, and median depressed area bare, smooth posteriorly with two short blunt carinae anterior to scutellum or slightly depressed medially. Axillae obliquely imbricate-alutaceous, appearing strigose, with anterior edge in same plane as scutellum base, convexly sloping posteriorly, with numerous dark, long setae; scutellum convex, dorsally circularly imbricate-alutaceous, becoming imbricate-coriaceous posteriorly, and with numerous dark, long setae. Dorsellum with a broadly rounded median lobe covering apex of scutellum. Propodeum without plical depression, with plical region narrow and anteriorly with V-shaped and posteriorly with Λ-shaped carinae touching medially; callar region slightly convex with long setae in outer half, with a moderately large spiracle smaller than a posterior ocellus and separated from anterior margin by distance equal to its own largest diameter. Acropleuron bare, alutaceous anteriorly and nearly polished posteriorly; cuticle very thin so that attachment site of mesotergal-mesopleural muscle clearly visible; mesepisternum with long white and erect setae, the setae denser in front of mid coxa. Hind coxa alutaceous to coriaceous, with dense white setae on anteroventral corner and along ventral margin of outer surface and with a few setae along dorsal edge. Mesotibia with 4 inconspicuous apical pegs. Fore wing 2.9–3× as long as wide; basal cell with uniformly distributed sparse setae; costal cell microsetose at base and apically, with about two lines of inconspicuous setae at front margin; parastigma with denser and darker setae than rest of disc which is evenly setose with long, brownish setae; venation with very long uncus and strongly enlarged stigma ( Figs 38 , 47 ), cc: mv: stv: pmv: uncus: u-pmv = 2.5–2.6: 2.9–3.1: 1: 1.7–1.8: 0.5: 0.2–0.33. Relative measurements: MSL 53–83, MSCL 23–38, MSCW 22–35, SCL 11–20, SCW 8–15, AXW 6–10, AXL 7–12, FWL 86–140, FWW 30–47, cc 24–39, mv 28–46, stv 9.5–15, pmv 17.5–25, uncus 5–7, u-pmv 2–5, HWL 74–120, HWW 15–31, MT 35–60, HT 31–55.

Metasoma with terga setose, smooth basally to finely alutaceous distally; Mt7 partially covering Mt8, Mt8 with a short dorsal surface anterior to emargination surrounding posteriorly facing anal sclerite; Mt2–Mt7 with nearly straight posterior margins. Ovipositor sheath 0.9–0.97× hind tibia length (0.8× in one specimen from The Netherlands). Relative measurements: MTL 61–110, MTW 24–45, OL 30–50.

MALE. Head ( Fig. 42 ) dark bluish-green with some golden lustre on lower face, scrobal depression with violet, blue, coppery, and golden lustres depending on viewing angle. Antenna brown with faint golden-green lustre under some angles. Mesosoma ( Fig. 42 ) dark with a faint blue hue and with median mesoscutal lobe and apex of scutellum with stronger bluish lustre; propodeum dark greenish-blue, shiny. Wings translucent with light brown venation. Legs brownish, with paler front femur and tibia. Metasoma brown with mainly violet and coppery lustres under some angles.

Head coriaceous-alutaceous except lower face finely coriaceous, with small setiferous pinprick-like punctures and numerous semierect setae, dark on parascrobal area and frontovertex and light on lower face (sculpture and setation more evident than in R. hungarica ); occiput imbricate-alutaceous; scrobal depression shiny, shallow, wide-ovoidal, without depression at apex of interantennal region, and delimiting a broad parascrobal region. Head 0.5× as long as wide in dorsal view, with ocelli arranged in an obtuse triangle. Eye microsetose, with setae conspicuous and longer than an ommatidium. In frontal view 1.4× as wide as high and toruli with ventral margin in line with lower orbit; scape imperceptibly curved in dorsal view, in outer view 2.2× as long as wide, ovoidal, widest mesally; in side view pedicel about 1.4× as long as wide, F1 inconspicuous, F2–F8 all petiolate and elongate, gradually shortened and widened toward last segment of clava, and all with long semierect setae; clava tapered to apex, about as long as combined length of apical two funiculars. Relative measurements: available specimens collapsed and variably fragmentary.

Thorax with long dark setae dorsally, 1.8× as long as wide; pronotum divided medially, imbricate-coriaceous; mesoscutum with deep notauli, 0.5× as long as wide, mid lobe reticulate anteriorly to imbricate-coriaceous toward median depression and lateral lobes, scutellar-axillar complex finely coriaceous, scutellum 1.4× as long as wide. Dorsellum narrow, linear. Propodeum smooth with a median carina and a few sparse setae laterally. Hind coxa smooth, finely coriaceous, with bare outer surface and sparse long setae along dorsal and ventral margins. Fore wing 2.5× as long as wide, entirely setose; venation with very long uncus and enlarged stigma ( Fig. 42 ), cc: mv: stv: pmv: uncus: u-pmv = 2.6: 2: 1: 2: 0.63: 0.2.

Metasoma petiolate in dorsal view ( Fig. 42 ), with first gastral segment compressed, about 2.6× as long as wide; terga finely coriaceous with long conspicuous setae.

VARIABILITY. Females seem to vary considerably in color from those with the scape and sides of the mesosoma yellow to those with these parts pale brown to brown (scape brown only in one specimen from The Netherlands).

RECOGNITION. Both sexes of this very distinct species have an extremely elongate uncus, and females have a characteristic fore wing infuscation pattern and the mesosoma with yellow to brownish sides and a metallic dorsum. Females are most similar to the Canarian endemic R. andriescui , but the ranges of the two species likely do not overlap and females can be separated using body color and sculpture (scrobal depression mostly smooth in females of R. rostrata ) as given in the key to females.

BIOLOGY. The syntypic series was reared in Austria from galls of Aphelonyx cerricola (Giraud) , Andricus hartigi (Hartig) , and A. coriarius (Hartig) (Ruschka 1921) , whereas in Romania and Czech Republic it was reared from galls of Biorhiza pallida (Olivier) (Suciu 1961; Bouček 1968), and in Hungary from Synophrus politus Hartig and Aphelonyx cerricola (Melika et al. 2002) ( Hymenoptera : Cynipidae ). Although the species has been reported several times from various cynipid galls on oak, Bouček (1977) presumed that the actual hosts are eggs of Orthoptera deposited on cynipid galls. There are two other records that cast doubt on R. rostrata as a parasitoid of cynipid gallmakers and suggest instead another host. In Hungary, it was reared from branches of Turkey oak and plum trees, supposedly parasitizing Eurytoma morio Boheman ( Hymenoptera : Eurytomidae ), a parasitoid of Scolytus rugulosus (Müller) ( Coleoptera : Curculionidae , Scolytinae ) (Erdös 1960). One specimen from Romania was also reared from a dead Cornus mas branch in an oak forest (AICF). Species of Reikosiella with known biology are parasitoids of Lepidoptera larvae (Yoshimoto 1969; Gibson 1995) and it is possible that R. rostrata is a parasitoid of inquiline caterpillars in oak cynipid galls [e.g. Pammene amygdalana (Duponchel) ] or some other Lepidoptera larvae associated with oak trees that pupate in hollow galls or under the bark. Suciu (1961) actually reared one specimen of R. rostrata from a large number of galls of Biorhiza pallida together with several moth specimens and Copidosoma truncatellum (Dalman) and C. terebrator Mayr ( Hymenoptera : Encyrtidae ), specialized parasitoids of Lepidoptera larvae.

DISTRIBUTION. Spain (Askew 1999; Askew & Nieves-Aldrey 2000; Askew et al. 2001; Askew & Nieves- Aldrey 2004), Germany (Vidal 2001), Austria (Ruschka 1921), Hungary (Erdös 1960; Melika et al. 2002), Czech Republic (Bouček 1968), Croatia, Montenegro (Bouček 1977), Romania (Suciu 1961; Andriescu 2003; Fusu 2008). Here newly reported for The Netherlands, France and Greece.

TAXONOMIC COMMENTS. The syntypes of Eupelmus rostratus are represented by 6 females and one male, all minuten pin-mounted to separate pith blocks. One female ( Fig. 41 ) has a lectotype label and the other 6 specimens have paralectotype labels by Zdenek Bouček (dated 1966). In order to preserve stability of nomenclature this previously unpublished lectotype designation is here validated. Ruschka (1921) stated that this species has affinities with both the urozonus species group (i.e. subgenus Eupelmus sensu Gibson, 1995 ) and the vesicularis species group (i.e. subgenus Macroneura sensu Gibson, 1995 ) but also some characters of Anastatus . He also suggested that it would be better to create a new genus for it, though he didn’t. A cytogenetic study of several Eupelminae genera has shown that E. rostratus has a different karyotype than Eupelmus species, but similar to Merostenus excavatus (Dalman) ( Fig. 2 a, b in Fusu 2008). Fusu (2008) also suggested that E. rostratus belongs to Reikosiella but did not formally propose a new combination pending a comprehensive revision of the genus. Gibson (1995) proposed that recognition of Merostenus as a separate genus could render Reikosiella paraphyletic, and this might explain the similarities in the chromosome complements of the two genera.

Askew & Nieves Aldrey (2000, 2004) treated this species in Eupelmus in the last published taxonomic work on European species of the genus, but several characters place it in Reikosiella (Hirticauda) . Though the flagellum is uniformly dark without white segments, the head in lateral view has the upper face under an angle with the lower face (lower parascrobal area and interantennal prominence protruding) and the scrobal depression is broad, shallow and extends to the inner orbits so that a differentiated parascrobal region is virtually absent; the fore wing is clearly elongate, with the marginal vein much longer than the costal cell and without a linea calva; and Mt7 (segment with spiracles) entire and not concealed under Mt6.

Figures

FIGURES 1 – 6. Reikosiella (Hirticauda) Ƥ heads: 1, R. rostrata. 2, R. andriescui. 3, R. gordoni. 4, R. cornuta. 5, R. hungarica. 6, R. tripotinorum. Scale bar 0.1 mm.

FIGURES 7 – 16. Reikosiella (Hirticauda) Ƥ: 7, R. andriescui dorsal habitus. 8, R. vanharteni head. 9, R. koreana head. 10, R. rostrata dorsal habitus. 11, R. hungarica dorsal habitus. 12, R. tripotinorum dorsal habitus. 13, R. gordoni dorsal habitus. 14, R. bolivari dorsal habitus. 15, R. graeca dorsal habitus. 16, R. cornuta dorsal habitus. Scale bar 0.5 mm for 7, 10 – 16 and 0.1 mm for 8 – 9.

FIGURES 45 – 54. Details of Reikosiella (Hirticauda) Ƥ. 45 – 48, R. rostrata: 45, dorsal body and wings; 46, head in frontal view; 47, detail of fore wing venation; 48, antenna. 49 – 52, R. gordoni: 49, dorsal body and fore wing; 50, head in frontal view; 51, detail of fore wing venation; 52, antenna. 53 – 54, R. hungarica: 53, detail of fore wing venation; 54, antenna. Scale bar 0.2 mm.

FIGURES 31 – 40. Reikosiella (Hirticauda) Ƥ fore wing venation: 31, R. andriescui (inverted image of left wing). 32, R. bolivari. 33, R. cornuta. 34, R. hungarica. 35, R. graeca. 36, R. gordoni (ventral side of left wing). 37, R. koreana. 38, R. rostrata. 39, R. tripotinorum. 40, R. vanharteni. Scale bar 0.2 mm.

FIGURES 41 – 44. Type specimens of Eupelmus rostratus (= Reikosiella rostrata) and a Merostenus excavatus 3: 41, lectotype Ƥ of E. rostratus (NHMW) with original labels (photo G. A. P. Gibson). 42, paralectotype 3 of E. rostratus (NHMW); insert: fore wing venation enlarged. 43, M. excavatus 3 head. 44, lateral M. excavatus 3 habitus. Scale bar 0.1 mm for 43 and 0.5 mm for 44.