Polynema (Doriclytus) vitripenne ( Foerster, 1847 )

Triapitsyn, Serguei V. & Fidalgo, Patricio, 2006, Definition of Doriclytus, stat. rev. as a subgenus of Polynema and redescription of its type species, P. (Doriclytus) vitripenne (Hymenoptera: Mymaridae), Zootaxa 1362, pp. 55-68 : 61-66

Polynema (Doriclytus) vitripenne ( Foerster, 1847)

( Figs 1–5, 7 )

Doriclytus vitripennis Foerster 1847: 227 –228. Type locality: environs of Aachen, Nordrhein-Westfalen, Germany.

Polynema euchariformis Haliday : Bakkendorf 1933: 71 –77 (misidentification).

Doryclytus [sic] vitripennis Förster : Soyka 1956: 15 –16.

Doriclytus vitripennis Förster : Graham, 1973a: 48 –49.

Type material

Holotype female [ NHMW, examined], on slide labeled: 1. " Doryclytus vitripennis Förster [female symbol] Ur-Type"; 2. " Type "; 3 "842"; 4. " Dor. vitripennis Förster, Type. Collect. G. Mayr prep. W. Soyka in Canadabal."). It is in fair condition but was rather poorly remounted (without clearing) from a minuten pin by W. Soyka. The specimen has one antenna and one pair of wings separated but under the same coverslip as the rest of the body. The mesosoma is mounted more or less dorsoventrally (at an angle) while the gaster is mounted laterally. The head and petiole are difficult to observe. The two?original (printed) labels are glued onto the fourth label; all other labels were made by W. Soyka, who also erroneously labeled a non-type NHMW specimen from Denmark, collected by O. Bakkendorf, as a "Co-Type".

Additional material examined

BELGIUM. Brabant, Ottignies, 25.x–1.xi.1980, P. Dessart [1 female, CNCI]. DENMARK. Praestevangen, 1928 or 1929, O. Bakkendorf ("Ex. Idiocerus confusus Flor in Salix cinerea L. O. Bakkendorf ...") [1 female, NHMW, locality and year of collection data given according to Bakkendorf (1933)]. RUSSIA. Moscow Region, Pushkino District, Mamontovka, Sosnovka, 16.viii.2003, S.V. Triapitsyn (on Salix sp. near Vetelka Stream) [1 female, UCRC]. SWEDEN: Gävleborg, Los, 1948 [1 female, MZHF]. Örebro: Örebro, x.1938 [1 female, MZHF]. Oset: 17.viii.1939 [1 female, MZHF]; 10.ix.1939, A. Jansson [1 female, MZHF]; x.1939 [1 female, MZHF]; iii.1941 [1 female, MZHF]. Uppsala, Vallentuna, 17.viii.1974, K.-J. Hedquist [1 female, MZLU].

Diagnosis

The combination of a very short mesosoma, a long ovipositor with a large basal loop, and a relatively short, flattened, and wide petiole is unique among the known European species of Polynema s. l. Neverthless, P. (Doriclytus) vitripenne was misidentified by Enock (1909) and then Bakkendorf (1933) who, however, provided a good illustration of this species under a different name (as P. euchariformis Haliday ). The species is indeed similar to P. (Doriclytus) euchariforme Haliday but also resembles some unidentified species collected recently. Three females of the similar, unidentified species were swept from willows, Salix spp., in Fryazevo, Moscow Region, Russia by SVT in August 2003 (UCRC). Another, especially similar, undetermined species was collected (1 female, UCRC) on a willow in Mamontovka, Moscow Region, Russia by SVT together with the female of P. (Doriclytus) vitripenne . This undetermined species also belongs to P. ( Doriclytus ) but, like P. (Doriclytus) euchariforme , differs from P. (Doriclytus) vitripenne in having a relatively shorter, but still distinctly exserted, straight, ovipositor without a large basal loop. Its petiole is not as short and dorso-ventrally flattened as in P. (Doriclytus) vitripenne but is still rather short for the genus and notably dilated basally. Likely the same species was mentioned by Graham (1973a) from Britain as being closely related to P. (Doriclytus) vitripenne . In both P. (Doriclytus) vitripenne and this undetermined species, the scutellum is notably wider than long whereas it is about as wide as long in P. (Doriclytus) euchariforme . The three species are also related to those misidentified by Bakkendorf (1933) as P. a t r a t u s Haliday and P. p u s i l l u s Haliday, one or both of which may in fact represent P. (Doriclytus) woodi Hincks or a very similar species, perhaps P. albitarse Kieffer. The latter is also a member of P. ( Doriclytus ), based on the study of its lectotype (in BMNH) by SVT. Bakkendorf (1933) reared one of these species in Denmark from the same leafhopper and plant hosts as P. (Doriclytus) vitripenne and provided an illustration of its habitus (misidentified as P. a t r a t u s). Apparently a complex of several closely related species of P. ( Doriclytus ) exists in Europe that parasitize leafhopper eggs on Salix spp. and Populus spp., likely those laid by various Idiocerinae associated with species of Salicaceae .

Redescription

FEMALE (n=4, including the holotype). Body mostly dark brown to black except petiole light brown to brown and basal metasomal terga brown. Appendages brown except distal funicle segments, clava, and apical tarsomeres dark brown; eyes dirty pink, ocelli pink.

Antenna ( Fig. 2 ) sparsely setose, clava more densely so. Scape excluding radicle about 2.5 x as long as wide and smooth; pedicel smooth, slightly longer than F1; F2 the longest funicle segment, a little longer than F3; F4 about as long as F6 and slightly longer than F5; F6 with 1 longitudinal sensillum; clava about 3.5 x as long as wide, a little longer than combined length of two preceding segments, with 7 longitudinal sensilla.

Mesosoma ( Fig. 3 ) very short (almost as broad as long, length/width about 8:7), and smooth, except for traces of very inconspicuous cellulate sculpture anteriorly on mesoscutum. Pronotum short, divided mediolongitudinally, each lobe with 6 or 7 pairs of short setae, all but one of them on the lateral margin; mesoscutum much wider than long; axillar seta short and weak; scutellum much wider than long (about 1.7:1); propodeum short, without a median carina.

Wings. Forewing ( Fig. 4 ) 3.2–3.3 x as long as wide; blade mostly hyaline except for a slight infumation behind base of venation, densely setose with rather short microtrichia beyond venation; longest marginal seta a little less than 1/2 greatest width of blade (0.40–0.47:1). Hind wing 23–32 x as long as wide; blade hyaline, with 3 complete rows of setae; longest marginal seta 4– 5 x as long as maximum width of blade.

Metasoma much longer than mesosoma. Petiole ( Fig. 5 ) about 1.8 x as long as wide, notably dilated and flattened, with inconspicuous transverse wrinkles medially. Ovipositor very long (its length varies a great deal, that is a common phenomenon among the Mymaridae with very long ovipositors), occupying almost entire length of gaster ( Fig. 7 ), with a very large basal loop, and usually greatly, but sometimes less so, exserted beyond gastral apex (by about 1/3–1/2 of total length of ovipositor); ovipositor sheaths not reaching tip of ovipositor (almost reaching in one specimen from Denmark with a relatively shorter ovipositor); ovipositor length/metatibia length ratio 2.0–2.7:1.

Measurements (holotype). Body: 1076; mesosoma: 400; gaster: 585; ovipositor: 1138. Antenna: scape: 91; pedicel: 61; F1: 52; F2: 133; F3: 114; F4: 84; F5: 70; F6: 85; clava: 170. Forewing: length/width: 1353/412; longest marginal seta: 166. Hind wing: length/ width: 1021/32; longest marginal seta: 145. Legs (given as coxa, femur, tibia, tarsus): fore: 130, 302, 285, 321; middle: 112, 233, 373, 373; hind: 161, 303, 479, 576.

MALE. Unknown. According to Bakkendorf (1933), this species is parthenogenetic (reproduces by thelytoky). One specimen [MZHF] from Småland, Skillingaryd, Jönköping, Sweden, collected by Anton Jansson, may represent a male of either P. (Doriclytus) vitripenne or, more likely, of a closely related species mentioned in the diagnosis above.

Hosts

Populicerus ? confusus (Flor) ( Hemiptera : Cicadellidae : Idiocerinae ) on Salix cinerea L. in Denmark ( Bakkendorf 1933); also was swept by SVT from a willow (determined by SVT as possibly S. cinerea ) together with a specimen of P. confusus in Mamontovka, Moscow Region, Russia. The biology of P. (Doriclytus) vitripenne was discussed by Bakkendorf (1933) (as P. euchariformis Haliday ).

Figures

FIGURES 1 – 4. Polynema (Doriclytus) vitripenne, female (from Oset, Örebro, Sweden except Fig. 4 from Mamontovka, Moscow Region, Russia). 1. Head, frontal view. 2. Antenna. 3. Mesosoma. 4. Forewing.

FIGURES 5 – 7. Polynema (Doriclytus) spp. 5, 7. P. (D.) vitripenne, female (from Oset, Örebro, Sweden), 5. petiole, 7. gaster. 6. P. (D.) euchariforme (from Glamorgan Co., Wales, UK), female prosternum and propleura.