Thoron metallicus Haliday

JOHNSON, NORMAN F. & MASNER, LUBOMIR, 2004, The Genus Thoron Haliday (Hymenoptera: Scelionidae), Egg-Parasitoids of Waterscorpions (Hemiptera: Nepidae), with Key to World Species, American Museum Novitates 3452, pp. 1-16 : 11-13

Thoron metallicus Haliday

Figures 2–5 , 10, 11 Thoron metallicus Haliday, 1833: 272 . Original description, keyed. Walker, 1836: 355 (description); Thomson, 1858: 420 (description); Kieffer, 1926: 171 (description, keyed); Hellén, 1971: 19 (description); Masner, 1972: 837 (synonymy); Kozlov, 1978: 622 (description); Masner and Huggert, 1979: 917 (diagnosis); Kozlov and Kononova, 1990: 322 (description).

Teleas (Thoron) metallicus: Blanchard, 1840: 290 . Not seen: reference from Dalla Torre (1898 b).

Thoron Metallicus: Kieffer, 1912: 104 . Description.

Teleas fornicatus Nees von Esenbeck, 1834: 292 . Original description. Walker, 1836: 355 (junior synonym of Thoron metallicus Haliday ); Walk­ er, 1874: 7 (figured).

Teleas solidus Nees von Esenbeck, 1834: 291 . Original description. Walker, 1836: 355 (junior synonym of Thoron metallicus Haliday ); Herrich­Schäffer, 1840: 58 (diagnosis);

Thoron gibbus Ruthe, 1859: 121 . Original description. Kieffer, 1926: 171–172 (description, keyed); Masner, 1972: 836 (taxonomic status); Masner and Huggert, 1979: 917 (taxonomic status). NEW SYNONYMY.

Thoron Gibbus : Kieffer, 1912: 106 (description).

Anteris nepea Ferrière, 1916: 71 . Original description, incorrect original spelling. Masner, 1972: 837 (junior synonym of Thoron metallicus Haliday ).

DESCRIPTION: Length 2.4 mm. Female A4 subequal A3, just barely longer than A5 (fig. 2); clava robust, 2.9 times longer than wide; apex of A1 well below top of vertex; female A2–A7 dark brown; male A11 1.6–1.8 times as long as wide; ocelli small, lateral ocellus separated from inner orbit by at least slightly less than twice its diameter (figs. 4, 5); central portion of mesoscutum and scutellum at most with minute setigerous punctures; notaulus long, almost percurrent (fig. 3), extending anteriorly beyond level of posterior margin of tegula, simple, without crenulae; mesoscutum with both long bristles and shorter underlying pilosity; metapleuron and lateral face of propodeum uniformly covered with long, silvery hairs (figs. 2, 11); marginalis thickened, and surrounding membrane deeply pigmented; postmarginal vein extremely short or absent, much shorter than length of stigmal vein; dorsellum spinose medially, short, subtriangular; dorsal surface of propodeum excavate medially; all coxae dark brown to black; hindfemur light brown, lighter in color than dark coxa; T1 with strong, smooth hump, sometimes low, not strongly raised; costae on T2 reaching at least to posterior third of tergite; T2 distinctly shorter than T3; T3 wider than long.

DIAGNOSIS: Thoron metallicus is distinguished from all other species by its pilose metapleuron, the small ocelli (POL 1.5–2 × OD), the short postmarginalis, and the enlarged area of pigmentation around the marginal vein.

MATERIAL EXAMINED: 660♀, 1923. Nearctic Region: CANADA: Québec: Gatineau Pk., Ridge Rd., 300 m, Ridge Rd. , 7.viii.1982, L. Masner, 2♀, 13 ( OSUC 77496 ) . Lac Jean­Venne , 45 ° 41 ̍ N, 76 ° 03 ̍ W, 20–25.vi.1995, yellow pan traps, sphagnum bog, 2♀ ( OSUC 77462 ) . Old Chelsea , 30.VI.1961, J.R. Vockeroth, 1♀ ( OSUC 77494 ) . Pontiac, Ft­Coulonge , 28.X.1992, Le­ Sage­Masner, Sift. berl. Selix [sic], 1♀ ( OSUC 77489 ) . Ontario: Essex Co., Pt. Pelee National Park, wooded area by west beach, 10–23.ix.1999, O. Lonsdale, Malaise / pan traps, debu00012571, 1♀. Fanshaw , 17.v.1982, A. Tomlin, 1♀ ( OSUC 77498 ) . Flamborough , 43 ° 23 ̍ 02 ̎ N, 80 ° 03 ̍ 10 ̎ W, 20–25.vi.1995, L. Masner, yellow pan traps, creek, 4♀, 23 ( OSUC 77470 , OSUC 77471 ) . Flint Hill nr. Kemptville , 12.vi.1983, L. Dumochel, 1♀ ( OSUC 77497 ) . Hess creek , 10 km S Kemptville, 18.vii.2001, L. Masner, yellow pan trap, 4♀ ( OSUC 77500 ) . London , 14.v.1982, interception trap, onion field, A. Tomlin, 1♀ ( OSUC 77495 ) . Mississippi Lake , 2–23.x.1991, BRC HYM TEAM, floating malaise trap, 1♀ ( OSUC 77490 ) . Mississippi Lake, McEwen’s Bay , 22– 29.v.1991, float pan trap, L. Dumochel, 1♀ ( OSUC 77499 ) . Ottawa, 22–26.ix.1998, J.R. Vockeroth, yellow pan trap, dry Typha / Carex marsh, 13. Outlet Beach , Prince Edward Co., 14.viii.1968, J. R. Vockeroth, 1♀. Oxford Mills, 29.v­1–vi.1973, L. Masner, 1♀; 12.vii.1984, 1♀ ( OSUC 59206 ) ; 25.vii.1979, 1♀; 8.viii.1984, 13; 15.viii.1984, 23 ( OSUC 59207 ) ; 10.ix.1971, L. Masner, taken on water weeds, 13 ( OSUC 77491 ) ; 13–20.vii.1973, G. Gibson, yellow pan trap, 13; 4.viii.1978, 13 ( OSUC 77492 ) ; 17.viii.1978, 13; 17–24.viii.1973, 23; 27.vii.1978, 23; 27.vii–3.viii.1973, 13; 20– 27.viii.1973, 13; 31.viii–7.ix.1973, 1♀. UNITED STATES: Indiana: Tippecanoe Co., iv.1977, J.F. MacDonald, malaise trap, 1♀ ( OSUC 77466 ) . Maryland: Prince Georges Co., Patuxent Res. Sta. , 22–26.vi.1980, pan trap, 1♀ ( OSUC 77469 ) . Massachusetts, Cape Cod, Eastham , 8.ix.1988, J.R. Vockeroth, pan trap, pool margin, Typha, Juncus , 2♀, 13 ( OSUC 77463–77465 ) . Ohio: Pickaway Co., Deer Creek St. Pk., 18– 19.viii.2002, 21–22.viii.1999, E. Dotseth, yellow pan trap, 13, 4♀. Virginia: Clarke Co. , Blandy Exp. Farm , 2 mi S Boyce, 23–31.v.1991, D.R. Smith, malaise trap, 2♀ ( OSUC 77467–77468 ) .

Palearctic Region: CZECH REPUBLIC: Čelákovice, Lipovka res., 6.iv.1993, J. Macek, 3♀; 20.vii–3.viii.1993, J. Macek, 13 ( OSUC 77479 ) ; 2–6.vi.1993, malaise trap, 1♀ ( OSUC 77480 ) ; 2– 19.vi.1994, malaise trap, 1♀; 8–16.vi.1993, pan trap, 1♀. Mer. Lanzhot Ranspurk , climax hardwood forest, 9–12.viii.1991, L. Masner, pan trap, 20♀, 143 ( OSUC 77478 ) . Lednice , 7–9.viii.1991, L. Masner, pan trap, riparian forest, 490♀, 833 ( OSUC 77457 , 77458 ) . Orlicke Hory, Dolni Cerna , 28.viii–12.ix.1993, J. Jezek, 243 ( OSUC 77488 ) . Praha­Stromovka , 18–19.viii.1999, 12♀, 183 ( OSUC 77459 , 77460 ) . Řevnice , env., 10– 12.ix.1999, L. Masner, yellow pan trap, 2♀ 13 ( OSUC 77486 ) . Šarka , creek, 8.ix.1999, L. Masner, yellow pan trap, 63 ( OSUC 77485 ) . Slapy, env., 22.viii.1999, L. Masner, yellow pan trap, pond, 3♀, 93. FRANCE: Dordogne, Couze St. Front, 27.vi–11.vii.1993, H. Tussac, malaise trap, 1♀ ( OSUC 77441 ) . Hérault, Montferrier sur Lez , 3 ° 51 ̍ E, 43 ° 40 ̍ N, 6.vi.1994, P.G. Mason, malaise trap, 1♀ ( OSUC 77481 ) . Dép. Var, Tanneron , env., 27–29.viii.1999, L. Masner, yellow pan trap, creek, 50♀, 43 ( OSUC 77455 , 77456 ) . HUN­ GARY: K ozseg ̎, 16–19.v.2001, L. Masner, yellow pan trap, sphagnum bog, 26♀ ( OSUC 77461 ) . IRELAND: Co. Dublin, Gollierstown , 25.vii.1945, A.W. Stelfox, 1♀, 13, A.W. Stelfox collecion ( OSUC 77443 ) ; 3.viii.1947, 13 ( OSUC 77445 ) ; 11.ix.1946, 1♀ ( OSUC 77444 ) . RUSSIA: Khakassia Rep. , 80 km N Shira, 460 m, 54 ° 59 ̍ N, 89 ° 32 ̍ E, 26.vii.2003, J. Peck, yellow pan traps near streamside, 03–112, 43 ( OSUC 749465– 79468 ) . SWEDEN: Halland, Lunna, Bolg , 19.viii.1973, L. Huggert, 1♀, 13 ( OSUC 77453 , 77454 ) . Västmanland, Kärrbo s:n, Solbacken, shore of Lake Mälaren , 15.iii–1.v.1989, G.E. Nilsson, malaise trap, 7♀ ( OSUC 43330 , 43318 , 43311 , 43284 , 43273 , 43253 , 43245 ) . TUNISIA: 1 km S Toborka , 8.iv.1994, M. Soderlund, 13 ( OSUC 77442 ) . UNITED KINGDOM: Buckinghamshire, Burnham Beeches , 26.viii.1984, L. Masner, screen sweeping, vegetation on sphagnum bed creek, 2♀, 33 ( OSUC 77448–77452 ) . Oxford , 25.v.1953, J.R. Vockeroth, 1♀ ( OSUC 77447 ) . Oxon; Barrow Farm Fen , NCC, 18.viii– 14.ix.1987, malaise trap, 23 ( OSUC 77482 ) . Oxon, Woodstock , 23.x.1952, 2♀ ( OSUC 77484 ) .

MATERIAL CITED IN LITERATURE ( Kozlov and Kononova 1990; O’Connor et al., 2004; Walker, 1836): IRELAND: Down, Holywood, at the edges of ponds, among roots of aquatic plants, and on the water, A.H. Haliday. Dublin, Gollierstown, 6.x.1946, 3.xiii.1947, A.W. Stelfox; Royal Canal, Luttrellstown, 28.ix.1986, J.M. O’Connor, 1♀. Kildare, Landenstown, 25.ix.1949, A.W. Stelfox. UNITED KINGDOM: near London, iii­x, at the roots of grass, moss, &c. Devonshire, by the edges of brooks and ponds. UKRAINE: Cherkasskaya obl., Kanyev, flood plain of Dnepr R., oak forest, 8.ii.1949, Kryshtal’, 1♀. Kievskaya obl., Fastov area, 11.vii.1972, S.V. Kononova, 13. AZERBAIJAN, Lenkoran’, area of Shakhagach, 22.v.1975, S.V. Kononova, 1♀.

COMMENTS: The gena in the males are quite variable, even within the same population. Some specimens (fig. 4) have the gena subparallel or even slightly bulging so that the head is widest across the genae and not across the compound eyes. In contrast, other specimens, collected at the same time and place (e.g., in the Czech Republic), have the genae distinctly receding immediately behind the compound eyes (fig. 5). All specimens from Britain and from the Nearctic region have expanded temples. Extreme dimorphism in male morphology is known in the Scelionidae (e.g., Johnson, 1984), and this variation may be a more subtle expression of the same phenomenon.

We have not been able to locate specimens of Thoron gibbus described by Ruthe. He distinguished his species from T. metallicus based on differences in the antennal clava. In all respects, as far as we can tell from the published data, the description is consistent with T. metallicus . Ruthe’s material was collected near Berlin, in moist habitats, and the species was not uncommon. Because the extensive material of Thoron from Europe consists of only a single species, we propose that Thoron gibbus is a junior synonym of T. metallicus (new synonymy).

Figures

Figs. 2–8. 2, Thoron metallicus Haliday, lateral habitus; 3, T. metallicus, dorsal habitus; 4, T. metallicus, head of male with expanded genae; 5, T. metallicus, head of male with receding genae; 6, T. rivalis, n.sp., antennal clava; 7, T. garciai, n.sp., antennal clava; 8, T. longicornis Masner and Huggert, head and antenna, lateral view (from Masner and Huggert, 1979).

Figs. 9–14. 9, Thoron lautus (Masner), head, dorsal view; 10, T. metallicus Haliday, head, frontal view; 11, T. metallicus, female, lateral view of mesosoma and base of metasoma; 12, T. rivalis, n.sp., lateral habitus; 13, T. spinifer, n.sp., dorsellum, lateral view; 14, T. spinifer, T2, dorsolateral view. Scale bar in millimeters.