Gonatocerus (Cosmocomoidea) oxypygus Foerster 1856

Gonatocerus (Cosmocomoidea) oxypygus Foerster, 1856

(Figs 283–303)

Gonatocerus oxypygus Foerster 1856: 118.

Female [lost from NHMW], type status not indicated. Type locality: unknown for both the lost type material and the neotype designated here (Europe, most likely Germany: Kirchner (1867) indicated Aachen as the original type locality).

Gonatocerus oxypygus Förster: Kirchner 1867: 201 (catalog); Kryger 1934: 503 (mentioned); Graham 1982: 224 (comments).

Gonatocerus ovicenatus Leonard & Crosby 1915: 545, 546 (illustrations). Type locality: Ithaca, Tompkins Co., New York, USA. Syn. n.

Lymaenon oxypygus (Förster): Debauche 1948: 81 (list).

Lymaenon ovicenatus (Leonard & Crosby): Burks 1958: 63 (catalog); Peck 1963: 25 (catalog); Viggiani 1969: 46 –48 (comments, records from Campania, Italy, host associations, redescription, illustrations); Viggiani 1988: 563 (host association); Viggiani & Jesu 1988: 1023 (host association).

Lymaenon tremulae Bakkendorf: Hincks 1960: 210 (in part, see “Material examined” below); Viggiani 1988: 562–564 (illustration of male genitalia, host association); Viggiani & Jesu 1988: 1023 (host association).

Lymaenon megalura Mathot 1969: 2 (list), 8–9, 10 (key).

Type locality: Leuven (Canal, as Louvain in the original description), Flemish Brabant, Belgium. Syn. n.

Gonatocerus tremulae (Bakkendorf): Matthews 1986: 222 (in part, misidentification of non-type specimens from England, see “Material examined” below); Donev 2001: 31 (record from Turkey); Donev 2005: 383 –384 (diagnosis, distribution); Pricop 2010b: 114 –116 (illustrations), 117 (valid species, diagnosis, distribution – but see comments under G. tremulae about misidentification).

Gonatocerus ovicenatus Leonard & Crosby: Huber 1988: 59 –60 (member of the ater species group, subsequent references, lectotype designation, diagnosis, redescription, host associations, records from Iran); Baquero & Jordana 2003: 16 –18 (synonymy, diagnosis, redescription, distribution, host associations); Pricop 2009a: 73 –74 (records from Romania); Pricop 2009b: 123, 125 (records from Romania, illustration); Huber et al. 2009: 271 (list); Pricop 2010a: 81 (records from Romania); Pricop 2010b: 113, 117 (diagnosis, distribution), 114–116 (illustrations).

Gonatocerus megalura (Mathot): Donev 1988d: 194 –195 (distribution).

Type material examined. Gonatocerus oxypygus Foerster: neotype female [MHNG], here designated in accordance with Article 75.3 ([ICZN] 1999) to avoid ambiguity regarding the identity of this species, to define the nominal taxon objectively and clarify its taxonomic status, and because the original type material of this species is lost. The neotype is on a slide (Fig. 283) labeled (the original label in?A. Foerster’s handwriting): “ Gonatocerus caudatus Frst. ” [Foerster’s manuscript name]. The neotype of G. oxypygus was remounted in Canada balsam at UCRC from an A. Foerster-style original mount on a minuten pin, one of two that were inserted in the same small balsa wood piece on a pin also labeled more recently in blue ball pen ink: “ Gonatocerus caudatus F.”. The neotype lacks F6–F8 and clava of one antenna (Fig. 285) and approximately apical halves of both ovipositor sheaths (Fig. 286), which are broken off, and also one fore leg and the apical part of one fore wing, but otherwise is in fair condition: it cleared surprisingly well considering that it is probably at least 150 years old. I searched for the type specimen(s) of G. oxypygus in A. Foerster’s collection during a visit to the NHMW in June 2007 and confirm that this (or these) has (have) been lost, hence the neotype designation.

Gonatocerus ovicenatus Leonard & Crosby: lectotype female on point [CUIC], designated by Huber 1988: 59. Label data of the lectotype as indicated by Huber (1988) plus a red label “ LECTOTYPE Gonatocerus ovicenatus Leonard & Crosby Des. Huber 1987 ”. Also 1 male paralectotype on point (originally labeled as an “allotype”) and 1 female and 1 male paralectotypes on slides [all CUIC]; the slides are labeled as follows: 1. “ Cornell University No. [443 (male) or 444 (female), followed by 3 or Ƥ symbols, respectively] SUB. SL. Gonatocerus ovicenatus Leonard & Crosby. Reared from eggs of Idiocerus gemmisimulans Leonard & Crosby Ithaca N. Y. DATE May 20, 1915 Paratype ”; 2. “ PARATYPE Cornell U. No. 443” (male) or “444” (female).

Gonatocerus megalura (Mathot): holotype female of Lymaenon megalura [ISNB] on slide (Fig. 288) labeled: 1. “Louvain (Canal) 12.VIII.43 (Roseaux). no296”; 2. “Dr. H. Debauche det. Lymaenon megalura Deb. Ƥ Type”. The holotype (Fig. 289) is in poor condition: insufficiently cleared, almost complete (lacking F2–F8 and clava of one antenna and also some leg segments), and mounted laterally, with one fore wing and both hind wings folded and mostly obscured.

Material examined. BULGARIA. BLAGOEVGRAD, Rila Mt., Bodrost, 1200 m, 27.vii.1984, A. Donev [1 Ƥ, PUPB] (det. by A. Donev as G. tremulae). SOFIA, Bankya, 26.v.1980, D. Kostadinov [1 Ƥ, PUPB] (det. by A. Donev as G. tremulae). GERMANY. BAVARIA, Munich, 23.vii.1958, E. Schmitscheck (“ ex. Idiocerus decimaquartus ”) [1 Ƥ, 1 3, and 2 damaged specimens of unknown sex, BMNH]. NORTH RHINE-WESTPHALIA:? Aachen [1 Ƥ, NHMW] (paralectotype of G. ater, Figs 290–292). Cologne, M. Boness: 30.vii.1962 [3 Ƥ, 3 3, NHMW]; 6.viii.1962 [1 Ƥ, NHMW]; 20.ix.1962 [1 Ƥ, NHMW]. Leverkusen, M. Boness: 16.x.1962 (on Rumex obtusifolius at Rhine River bank) [2 Ƥ, NHMW]; 16.x.1962 (on Salix sp. at Rhine River bank) [2 Ƥ, NHMW]. GREECE. CENTRAL MACEDONIA, Lake Kerkini, Kerkini Marsh, 41°13’32.8’’N 23°05’04.2’’E, 45 m, G. Ramel: 28.iii–3.iv.2007 [1 Ƥ, UCRC]; 1–17.iv.2007 [1 Ƥ, BMNH]. HUNGARY. BÁCS-KISKUN, Kelebia, 3.v.1949, J. Erdös [1 Ƥ, NHMW / HNHM]. IRAN. ZANJAN, 30 km W of Zanjan on Tabriz road, 9.vi.1978, J.T. Huber (sweeping understory in poplar grove) [2 Ƥ, BMNH, UCRC] (det. by J.T. Huber as G. ovicenatus).

ITALY. PIEDMONT, Turin Prov., Pessione, 21.viii.1984, Tronellini (“ ex. Rhytidodus decimusquartus on Populus euroamericana”) [2 Ƥ, DEZA] (det. by G. Viggiani as Lymaenon tremulae). ROMANIA. [MOLDOVA], Botoşani Co., Cucoräni, 2.ix.2006, E. Pricop [1 Ƥ, EPPC] (det. by E. Pricop as G. tremulae). RUSSIA. LENINGRADSKAYA OBLAST’, Radchenko [Railway Station], 10.ix.1978, V.A. Trjapitzin [1 Ƥ, ZIN]. STAVROPOL’SKIY KRAY, Prietokskiy, V.V. Kostjukov: 28.viii.2002 [5 Ƥ, UCRC]; 29.viii.2002 [1 Ƥ, 1 3, UCRC]; 14.vii.2003 [4 Ƥ, 1 3, UCRC]; 7.viii.2003 [3 Ƥ, UCRC]; 12.viii.2003 [15 Ƥ, 6 3, UCRC, ZIN]; 14.viii.2003 [2 Ƥ, UCRC]. TURKEY. SAKARYA, Karasu, 21.vii.1997, A. Donev [1 Ƥ, PUPB] (det. by A. Donev first as G. tremulae (Donev 2001) and then as G. ovicenatus). UK. ENGLAND: Buckinghamshire Co., Burnham Beeches, Z. Bouček (det. as G. tremulae by Z. Bouček and M.J. Matthews): 25.viii.1974 [5 Ƥ, BMNH]; 14.ix.1974 [6 Ƥ, BMNH]. East Riding of Yorkshire Co., Allerthorpe Common, 1.ix.1953, W.D. Hincks [1 Ƥ, MMUE] (det. as L. tremulae by W.D. Hincks and as G. tremulae by M.J. Matthews). Surrey Co., Dorking, Leith Hill, 26.viii.1984, J.S. Noyes [1 Ƥ, BMNH] (det. as G. tremulae by M.J. Matthews). Country or locality not indicated (most likely Aachen area, NORTH RHINE-WESTPHALIA, GERMANY): 1 Ƥ, potential paralectotype of G. ater Foerster [MHNG] (label information listed under G. ater). 1 Ƥ [MHNG] on minuten pin originally labeled: 1. [in?A. Foerster’s handwriting, the original label now glued onto the neotype slide] “ Gonatocerus caudatus Frst. ” [Foerster’s manuscript name]; 2. [in blue ball pen ink, recent label] “ Gonatocerus caudatus F.”. 1 Ƥ [MHNG] on a minuten pin inserted in a small balsa wood piece on a pin labeled: 1. [in?Foerster’s handwriting] “ Gonatocerus ecaudatus Frst. ” [Foerster’s manuscript name]; 2. [in blue ball pen ink] “ Gonatocerus ecaudatus F.” (mounted together, but on separate minuten pins, with 2 females of G. ater s. l.). 1 Ƥ [MHNG] on a minuten pin piece glued to a small balsa wood piece on a pin labeled: 1. [in Foerster’s handwriting] “ Cosmocoma diversicornis Frst. ” [Foerster’s manuscript name]; 2. [in blue ball pen ink] “ Cosmocoma diversicornis F”.

Extralimital records. USA. NEW YORK, Ontario Co., Geneva, 42°52’46’’N 77°00’40’’W, 185 m (on Lombardy poplar, Populus nigra, roadside of County Road 6): 3.viii.2010, S.V. Triapitsyn [2 Ƥ, 4 3, UCRC]; 23.ix.2010, S.V. Triapitsyn, G. Loeb [4 Ƥ, UCRC].

Distribution. PALAEARCTIC: Belgium *, Bulgaria (Donev 1988d [as G. megalura], 2005 [as G. tremulae]), Germany, Greece *, Hungary *, Iran (Huber 1988; Fallahzadeh & Huber 2011) [as G. ovicenatus], Italy (Viggiani 1969 [as Lymaenon ovicenatus]; Viggiani 1988 [also as Lymaenon tremulae]; Viggiani & Jesu 1988 [also as L. tremulae]), Netherlands (Noyes 2012 [as G. ovicenatus]), Romania (Pricop 2009a, 2010a, b [as G. ovicenatus and (2010b only) also as G. tremulae), Russia *, Spain (Baquero & Jordana 2003 [as G. ovicenatus]), Turkey (Donev 2001 [as G. tremulae]), and UK (England) (Hincks 1960 [as L. tremulae, in part]; Matthews 1986 [as G. tremulae]; Baquero & Jordana 2003 [as G. ovicenatus]). NEARCTIC: USA (New York). This Palaearctic species was apparently unintentionally introduced with poplars (hosts of the Idiocerinae) into the USA (Huber 1988); however, Baquero & Jordana (2003) later noted, without providing any data, that G. ovicenatus was probably not established there. Here I confirm establishment of G. oxypygus in North America (see “Extralimital records”). Populus nigra is an introduced species in North America; at the same time my attempts to collect G. oxypygus in upstate New York on Eastern cottonwood, Populus deltoides, which is native to North America, failed (Shackford 2012).

Redescription. FEMALE (neotype of G. oxypygus, holotype of Lymaenon megalura, paralectotype of G. ater, and non-type specimens from the Palaearctic region). Body length 930–1300 µm. Body (Figs 289, 291) dark brown to black, appendages mostly brown to dark brown.

Antenna (Figs 285, 290, 293, 297) with radicle 0.24–0.3× total length of scape, rest of scape 2.3–3.2× as long as wide; pedicel longer than F1; F1 the shortest funicle segment, F3 a little longer than F2 or F4, F5 the longest funicle segment, the following funicle segments usually each progressively slightly shorter than preceding one except F6 sometimes as long as or shorter than F7; mps on F3 (usually 0, rarely 1), F5 (usually 2, occasionally 1), F6 (1 or 2), F7 (2), and F8 (2); clava with 8 mps, 2.6.–3.4× as long as wide, at least a little (usually notably) shorter than combined length of F6–F8. In the extralimital female paratype of G. ovicenatus, F5 bears only 1 mps and F6 lacks mps.

Mesosoma (Figs 289, 291, 298) shorter than metasoma. Propodeum (Figs 284, 294) with fine, subparallel, submedian carinae close to each other and usually not extending to anterior margin of propodeum. Fore wing (Figs 287, 292, 296, 299) 2.7–2.9× as long as wide; longest marginal seta 0.18–0.23× maximum wing width; disc almost hyaline, bare behind venation except for 1–3 setae just behind stigmal vein. Hind wing (Figs 292, 296) 12–14× as long as wide; disc almost hyaline; longest marginal seta 1.4–2.0× maximum wing width.

Metasoma (Figs 289, 291, 298). Petiole about 0.3× as long as wide, narrower basally than apically. Ovipositor occupying from about 0.9× to entire length of gaster (Figs 286, 289, 291, 295, 298) and sometimes projecting forward under petiole and occasionally under posterior part of propodeum, and markedly exserted beyond gastral apex (by 0.2–0.4× own length), 2.6–3.1× as long as mesotibia; when very long, ovipositor and/or ovipositor sheaths often a little bent down apically (Figs 289, 295).

Measurements (µm) of the neotype. Head: 203; mesosoma 406; gaster 707; ovipositor 1070. Antenna: scape minus radicle 100; pedicel 55; F1 32; F2 47; F3 61; F4 53; F5 73; F6 61; F7 64; F8 51; clava 150. Fore wing 1218:437; longest marginal seta 100. Hind wing width 73; longest marginal seta 121.

MALE (specimens from the Palaearctic region). Body length 950–1140 µm. Similar to female including the shape of submedian carinae on the propodeum (Fig. 301) except for normal sexually dimorphic features and the following. Body brown to dark brown, antenna mostly brown, legs light to dark brown. Antenna (Fig. 300) with scape very short, about 1.8× as long as wide, pedicel very small. Fore wing (Fig. 303) 2.6–2.9× as long as wide; hind wing (Fig. 303) about as wide as in female. Genitalia (Fig. 302) large, about 0.75× length of gaster.

Diagnosis. Gonatocerus oxypygus is readily distinguishable from all other Palaearctic species of the subgenus by the combination of the fine, subparallel, submedian propodeal carinae that are close to each other and usually not extending to anterior margin of propodeum (Figs 284, 294, 301), and a markedly exserted ovipositor often a little bent down apically (Figs 286, 289, 291, 295, 298).

Also see Huber (1988) and Baquero & Jordana (2003) for the diagnoses of G. ovicenatus, as well as G. tremulae, below.

Hosts. Populicerus sp. [as Idiocerus sp.] in Italy (Viggiani 1969 [as Lymaenon ovicenatus]), and Rhytidodus decimaquartus (Schrank) in the USA (Leonard & Crosby 1915 [as G. ovicenatus]; Peck 1963 [as L. ovicenatus]; Huber 1988 [as G. ovicenatus]) [as Idiocerus gemmisimulans Leonard & Crosby, Idiocerus scurra (Germar), and Rhytidodus decimasquartus (Schrank), respectively] (Cicadellidae: Idiocerinae). Viggiani (1988) and Viggiani & Jesu (1988) also indicated R. decimaquartus [as R. decimusquartus] as the host of L. ovicenatus (also as the misidentified L. tremulae) in Italy. Also see Peck (1951) and Burks (1958).

Comments. Although the very short original diagnosis is not very helpful to determine the true identity of G. oxypygus, the indication (Foerster 1856, p. 118) that it differs from G. longicornis Nees ab Esenbeck “by its brownish legs and a strongly projecting ovipositor equaling almost to 1/3 of abdomen [i.e., gaster] length” (translation from German) makes it possible to determine beyond the reasonable doubt that G. oxypygus is conspecific with G. ovicenatus. Although Graham (1982) thought that G. oxypygus might be the same as G. novickyi and also G. fossarum (a synonym of G. novickyi), I consider the latter possibility much less likely because of its different, distinctive body color pattern; I found no specimens of G. novickyi (apparently an uncommon species in Europe) in the A. Foerster collection at NHMW. At the same time specimens of the species we know as G. ovicenatus are present among his mymarids both in NHMW and MHNG and fit the original diagnosis of G. oxypygus well. Therefore, as first reviser, I select a neotype of G. oxypygus from one of Foerster’s specimens in MHNG conspecific with G. ovicenatus and synonymize the latter under the earlier described G. oxypygus. Foerster’s specimens of Mymaridae found their way to MHNG via Gustav L. Mayr from Vienna (Huber & Fidalgo 1997) and very likely were collected in the Aachen area, North Rhine-Westphalia, Germany, the probable type locality of G. oxypygus. Most if not all of Foerster’s specimens from Aachen area were apparently collected by Foerster himself; although most of his specimens of Mymaridae in NHMW have printed labels “Coll. G. Mayr” on them, these were probably added later either by G.L. Mayr himself or, more likely, by a curator there simply because they came from Mayr’s collection but not necessarily because he collected them himself.

The holotype female of Lymaenon megalura is a typical G. oxypygus as treated here, a species which apparently was not known to H.R. Debauche and G. Mathot. Mathot’s confusion most likely was the result of how the holotype of L. megalura had been mounted: he apparently failed to recognize the correct shape of the dorsellum because of the lateral mount, and also one of its fore wings is folded in such a way that its apical part is positioned over the base of the other fore wing, thus creating a false impression that the fore wing disc is setose behind the marginal vein (Fig. 289). Therefore, in his key to species of Lymaenon, G. megalura can only be reached if one incorrectly assumes it does not have a rhomboidal dorsellum.