Pteromalus janstai, Baur, Hannes, 2015

Baur, Hannes, 2015, Pushing the limits - two new species of Pteromalus (Hymenoptera, Chalcidoidea, Pteromalidae) from Central Europe with remarkable morphology, ZooKeys 514, pp. 43-72 : 52-58

Taxon classification Animalia Hymenoptera Pteromalidae

Pteromalus janstai sp. n. Fig. 3

Type material.

Holotype ♀ Switzerland, Canton Wallis, Kippel, Zend, 2100 m, 46.4069°N, 7.7494°E, 15.07.2005, leg. P. Jansta & H. Baur, 15-vii-2005, on Larch ( Larix decidua Mill.), NMBE (Baur 2410). Paratype 1 ♀, same data as holotype, BMNH (Baur 2411). Paratype 1 ♂ Switzerland, Canton Grisons, Samedan, Blais Granda, 2100 m, 46.4412°N, 9.86456°E, 10-viii-1998, leg. H. Baur, NMBE (Baur 2412).

Description, female.

Color: Head and mesosoma: green to blue-green with metallic luster; setae on head and mesosoma: fuscous, inconspicuous; tegula: green; setae on callus of propodeum: whitish.

Scape: fuscous with basal third testaceous; pedicel: fuscous; flagellum: fuscous.

Fore wing: hyaline; fore wing venation: brownish; setae on fore wing: fuscous; hind wing: hyaline.

Coxae: green; trochanters: slightly greenish, testaceous at tips; pro- and mesofemur: green, testaceous in apical quarter, metafemur: green, testaceous in apical sixth; protibia: testaceous, meso- and metatibia: testaceous, medially slightly infuscate; tarsi: testaceous, apical segments slightly infuscate; pretarsi: slightly infuscate.

Petiole: dark purplish; gaster: green to blue-green with metallic luster; gastral terga: one to five with strong purplish tinge.

Sculpture: Head in frontal view: finely reticulate with moderately high septae; clypeus: striate; area between clypeus and malar sulcus: finely reticulate.

Mesoscutum: finely reticulate, meshes moderately high, areoles small and not enlarged in posterior part of sclerite; scutellum: reticulate, meshes about as strong and coarse as on posterior part of mesoscutum; frenum: reticulate, meshes larger than those on scutellum; axilla: reticulate, about as strong as on central part of scutellum; prepectus upper triangular area: weakly reticulate; upper mesepimeron: anteriorly smooth, posterior corner distinctly alutaceous; upper mesepisternum: reticulate, about as strong than on mesoscutum; metapleuron: weakly reticulate, less strong as on mesepisternum.

Coxae: weakly reticulate.

Median area of propodeum: uniformly reticulate, as strong as on mesoscutum; inner corner of anterior plica: with a smooth depression and transverse carinae; nucha: reticulate, as strong as on median area of propodeum; callus of propodeum: weakly reticulate; paraspiracular sulcus: smooth with few transverse costulae.

Petiole in dorsal view: smooth; gastral terga: smooth and shining, third to fifth tergum anteriorly, sixth tergum and syntergum wholly alutaceous.

Shape and structure: Head in frontal view: subtrapezoid (Fig. 3A); gena in frontal view: buccate; temple in dorsal view: obtuse (Fig. 3B); forming an angle with occiput of: 110 degrees; occipital carina: absent; torulus position with respect to lower ocular line: above; lower face in lateral view: weakly curved, receding with respect to upper face: weakly, forming an angle of: 35 degrees; scrobe: narrow, moderately deep; malar sulcus: superficial, but traceable; clypeus, anterior margin: widely and shallowly emarginate, medially slightly inclined above anterior edge (Fig. 3A); gena near mouth: terete; tentorial pit: indistinct (Fig. 3A); mouth extension: not conspicuously enlarged (Fig. 3A); mandibular formula: 3-4.

Antenna (Fig. 3C). Antennal formula: 11263; scape reaching: middle of anterior ocellus; flagellum: almost filiform; first anellus: strongly transverse; second anellus: strongly transverse; first funicular segment: very slightly constricted at base; setae on flagellum: moderately thickly clothed with setae standing out at an angle of 10-20 degrees, length of setae less than half the breadth of flagellar segments; number of rows of longitudinal sensilla on first funicular segment: 2, on sixth: 1-2.

Mesosoma in lateral view: rather flattened; propodeum in lateral view sloping with respect to dorsal plane of mesoscutum and scutellum at an angle of: 20 degrees (Fig. 3D); pronotum breadth with respect to mesoscutum breadth: distinctly narrower; pronotum collar: horizontal, well defined, its length with respect to mesoscutum length: one sixth, its anterior margin: finely carinate; pronotum posterior margin: thin, shiny strip; notaulus: superficial, reaching: two thirds along mesoscutum; scutellum in lateral view: almost flat; scutellum in posterior view: almost flat medially; scutellum posterior margin projection: level of anterior margin of dorsellum; scutellum posterior margin in posterior view: straight; frenal line: finely indicated, especially on sides; prepectus upper triangular area: separated by a strong carina; upper mesepimeron: strongly narrowing below, not reaching base of mesopleuron; propodeum (Fig. 3F): anterior plica: present, almost straight in anterior part; posterior plica: present, joining or almost joining anterior plica; orientation of posterior plicae: almost parallel; median carina of propodeum: mostly effaced; nucha: elevated but not clearly differentiated from median area of propodeum; spiracle: oval, size: small, separated from anterior margin of propodeum by: shortest diameter; callus pilosity: relatively sparsely setose; paraspiracular sulcus: narrow and deep.

Fore wing (Fig. 3E). Fore wing apex with respect to apex of gaster when folded back: just reaching; basal cell number of setae: 9-12 setae in distal part; basal setal line: complete, with: 11-12 setae; cubital setal line: incomplete, with: 4-8 setae; costal cell pilosity on dorsal side: bare; costal cell pilosity on lower side: with numerous setae in distal half and one setal line extending to base; speculum on upper side: bare, widely open below; fore wing disc: moderately thickly pilose; marginal setae: present, short; stigma: subrectangular, small; uncus: short.

Femora: slender; metatibia: gradually widening towards apex; metacoxa pilosity, dorsally: bare.

Petiole in dorsal view: conical, in ventral view: open; gaster in dorsal view: very elongate and acuminate; gastral terga: strongly convex; posterior margin of first gastral tergum: entire; first gastral tergum reaching: one fourth of gaster; tip of hypopygium reaching: almost three fifths of gaster (Fig. 3G); ovipositor sheath: distinctly protruding.

Length and body ratios: Body length: 3.9-4 mm; mesoscutum breadth: 815-829 µm.

Head breadth to height: 1.35-1.39; head breadth to length: 2.08-2.1; head breadth to mesoscutum breadth: 1.18; lower face height to head height: 0.42-0.44; POL to OOL: 1.19-1.2; eye height to breadth: 1.54-1.65; eye distance to height: 1.4-1.46; temple length to eye length: 0.36-0.45; malar space to eye height: 0.45-0.48.

Pedicel plus flagellum length to head breadth: 1.05-1.07; scape length to eye height: 0.81-0.86; scape length to breadth: 6.05-6.39; pedicel length to breadth: 1.51; pedicel length to first funicular segment length: 0.64-0.68; first funicular segment length to breadth: 1.77-1.83; sixth funicular segment length to breadth: 1.06-1.1; first funicular segment breadth to clava breadth: 0.8-0.84; clava length to breadth: 2.09-2.24.

Mesosoma length to mesoscutum breadth: 1.7-1.71; mesoscutum breadth to length: 1.44-1.52; mesoscutum length to scutellum length: 1.13-1.22; propodeum length to scutellum length: 0.59-0.61; plica distance to propodeum length: 1.2-1.36.

Fore wing length to breadth: 2.24-2.3; marginal vein length to stigmal vein length: 1.7-1.78; postmarginal vein length to stigmal vein length: 0.93-0.99.

Metafemur length to breadth: 3.88-4.47; metatibia length to breadth: 7.19-7.29; metatarsus length to metatibia length: 0.8.

Gaster length to breadth: 5.04-5.35; gaster length to mesosoma length: 1.51-1.52.

Description, male.

Color: Head and mesosoma: bright green to blue-green with metallic luster; setae on head: whitish, inconspicuous, on mesosoma: whitish, inconspicuous; tegula: green; setae on callus of propodeum: whitish.

Scape: fuscous with basal two fifths testaceous; pedicel: fuscous; flagellum: brown.

Fore wing: hyaline; fore wing venation: brownish testaceous; setae on fore wing: fuscous; hind wing: hyaline.

Coxae: green; pro- and mesotrochanter: slightly infuscate, metatrochanter: fuscous; pro- and mesofemur: infuscate, testaceous in apical third, metafemur: green, testaceous on tips; tibiae: testaceous; protarsus: slightly infuscate, meso- and metatarsus: testaceous, apical segments slightly infuscate; pretarsi: slightly infuscate.

Petiole: dark purplish; gaster: green; gastral terga: basal terga with large dark yellow spot.

Sculpture: Head in frontal view: finely reticulate with moderately high septae; clypeus: striate; area between clypeus and malar sulcus: finely reticulate.

Mesoscutum: finely reticulate, meshes moderately high, areoles small and not enlarged in posterior part of sclerite; scutellum: weakly reticulate, meshes less strong and coarse than on posterior part of mesoscutum; frenum: weakly reticulate, meshes larger than those on scutellum; axilla: reticulate, about as strong as on lateral part of scutellum; prepectus upper triangular area: weakly reticulate; upper mesepimeron: anteriorly smooth, posterior corner distinctly alutaceous; upper mesepisternum: reticulate, about as strong as on mesoscutum; metapleuron: weakly reticulate, less strong than on mesepisternum.

Pro- and mesocoxa: finely alutaceous, metacoxa: finely reticulate.

Median area of propodeum: uniformly reticulate, as strong as on mesoscutum but with smaller meshes; inner corner of anterior plica: with a smooth depression and transverse carinae; nucha: reticulate, as strong as on median area of propodeum; callus of propodeum: weakly reticulate; paraspiracular sulcus: smooth with few transverse costulae.

Petiole in dorsal view: smooth; gastral terga: smooth and shining, second to sixth tergum and syntergum alutaceous.

Shape and structure: Head in frontal view: subtrapezoid; gena in frontal view: buccate; temple in dorsal view: obtuse; occipital carina: absent; torulus position with respect to lower ocular line: distinctly above; lower face in lateral view: rather flat, receding with respect to upper face: weakly, forming an angle of: 35 degrees; scrobe: narrow, moderately deep; malar sulcus: superficial, but traceable; clypeus, anterior margin: widely and shallowly emarginate, medially slightly inclined above anterior edge; gena near mouth: terete; tentorial pit: indistinct; mouth extension: not conspicuously enlarged; mandibular formula:?3-4 (the mandibles are in the single male concealed, but the mandibular formula is most likely the same as in females).

Antenna (Fig. 3H). Antennal formula: 11263; scape reaching: posterior edge of anterior ocellus; flagellum: filiform; first anellus: strongly transverse; second anellus: strongly transverse; first funicular segment: slightly conical; setae on flagellum: thickly clothed with setae standing out at an angle of 50-60 degrees, length of setae slightly shorter than half the breadth of flagellar segments; number of rows of longitudinal sensilla on first funicular segment: 1, on sixth: 1.

Mesosoma in lateral view: rather flattened; propodeum in lateral view sloping with respect to dorsal plane of mesoscutum and scutellum at an angle of: about 25 degrees; pronotum breadth with respect to mesoscutum breadth: distinctly narrower; pronotum collar: horizontal, well defined, its length with respect to mesoscutum length: one sixth, its anterior margin: slightly elevated edge, medially carinate; pronotum posterior margin: thin, shiny strip; notaulus: superficial, reaching: two thirds along mesoscutum; scutellum in lateral view: almost flat; scutellum in posterior view: almost flat medially; scutellum posterior margin projection: level of anterior margin of dorsellum; scutellum posterior margin in posterior view: narrowly emarginate in the middle; frenal line: finely indicated, especially on sides; prepectus upper triangular area:? (the lower part of the prepectus is concealed in the single male, but the character state is likely to be the same as for the females); upper mesepimeron: strongly narrowing below, not reaching base of mesopleuron; anterior plica: present, almost straight in anterior part; posterior plica: present, joining anterior plica; orientation of posterior plicae: almost parallel; median carina of propodeum: anteriorly indicated, effaced posteriorly; nucha: elevated but not clearly differentiated from median area of propodeum; spiracle: oval, size: small, separated from anterior margin of propodeum by: shortest diameter; callus pilosity: relatively sparsely setose; paraspiracular sulcus: narrow and deep.

Fore wing apex with respect to apex of gaster when folded back: not exceeding; basal cell number of setae: with up to 10 setae in distal part; basal setal line: complete, with: 11 setae; cubital setal line: incomplete, with: 4 setae; costal cell pilosity on dorsal side: bare; costal cell pilosity on lower side: with numerous setae in distal half and a complete setal line extending to base; speculum on upper side: bare, widely open below; fore wing disc: moderately thickly pilose; marginal setae: present, short; stigma: subrectangular, small; uncus: short.

Femora: slender; metatibia: gradually widening towards apex; metacoxa pilosity, dorsally: bare.

Petiole in dorsal view: conical, in ventral view: open; gaster in dorsal view: elongate, obtuse; gastral terga: weakly sunken; posterior margin of first gastral tergum: entire; first gastral tergum reaching: slightly less than one third of gaster.

Length and body ratios: Body length: 3.1 mm; mesoscutum breadth: 732 µm.

Head breadth to height: 1.44; head breadth to length: 2.06; head breadth to mesoscutum breadth: 1.17; lower face height to head height: 0.51; POL to OOL: 1.33; eye height to breadth: 1.39; eye distance to height: 1.46; temple length to eye length: 0.38; malar space to eye height: 0.44.

Pedicel plus flagellum length to head breadth: 1.3; scape length to eye height: 0.84; scape length to breadth: 5.42; pedicel length to breadth: 1.28; pedicel length to first funicular segment length: 0.54; first funicular segment length to breadth: 2.08; sixth funicular segment length to breadth: 1.41; first funicular segment breadth to clava breadth: 0.97; clava length to breadth: 3.25.

Mesosoma length to mesoscutum breadth: 1.65; mesoscutum breadth to length: 1.44; mesoscutum length to scutellum length: 1.23; propodeum length to scutellum length: 0.64; plica distance to propodeum length: 1.1.

Fore wing length to breadth: 2.11; marginal vein length to stigmal vein length: 1.75; postmarginal vein length to stigmal vein length: 0.91.

Metafemur length to breadth: 4.3; metatibia length to breadth: 7.04; metatarsus length to metatibia length: 0.79.

Gaster length to breadth: 3.38; gaster length to mesosoma length: 1.19.

Comment.

The dorsoventrally compressed mesosoma and the shape of the propodeum allowed an easy association of the females with the male even though they were collected in separate localities (about 160 km as the crow flies).

Diagnosis.

Pteromalus janstai sp. n. is distinguished from all known species of Pteromalus species by the following combination of characters: mesosoma strongly flattened; female gaster elongate, laterally strongly compressed, more than 5 times as long as broad.

The female keys out in Graham (1969) via couplets 1, 2, 7-9, 11, 12, 14, 49, 52-56, 58, 59, 60, 62 to couplet 63, where it fits neither of the two species, Pteromalus dispar (see below) and "H. sp. indet. C". The male keys out via couplets 1-3, 5, 7, 10, 11, 14-19, 40, 44, 50, 52, 53, 54, 55, 56, 57, and 59 where both options don’t match well.

Most similar are the following species but they differ - among many other characters mentioned in the description - by a rather more strongly bent mesosoma and a much less elongate female gaster:

Pteromalus cyniphidis (Linnaeus, 1758) (syn. Pteromalus capreae (Linnaeus, 1761)), Pteromalus dispar (Curtis, 1827), Pteromalus dolichurus (Thomson, 1878), Pteromalus fasciatus (Thomson, 1878), Pteromalus pontaniae (Askew, 1985) and Pteromalus tereus Walker, 1839. Source of information, beside the keys of Graham (1969) and Askew (1995): Pteromalus dispar 2 ♀ 1 ♂ from Denmark and Switzerland in NMBE (Baur 2542-2544); specimens compared with material identified by Graham and Bouček as well as lectotypes of synonyms of Pteromalus dispar , that is, ♀ Pteromalus mesochlorus Walker, 1835, ♀ Pteromalus saravus Walker, 1845, ♀ Pteromalus basalis Walker, 1835, and ♂ Pteromalus cabarnos Walker, 1839 in BMNH. Lectotype ♀ of Pteromalus dolichurus and of Pteromalus fasciatus in LUZM, and lectotype ♂ of Pteromalus tereus in BMNH. Furthermore, Veli Vikberg kindly compared photographs of Pteromalus janstai sp. n. with specimens of Pteromalus cyniphidis in VVC. Some of these specimens belong to the same reared series from which the neotype ♂ of Pteromalus cyniphidis was selected by Vikberg and Askew (2006). Vikberg (pers. comm.) confirmed that the two species are clearly separated by the mentioned characters.

Etymology.

Pteromalus janstai sp. n. is named after Petr Jansta, who collected the female specimens. The name “janstai” is a noun in the genitive case and need not agree in gender with the generic name.

Biology.

Host unknown. The females of Pteromalus janstai sp. n. were swept on some isolated Larch trees ( Larix decidua ) in an Alpine meadow. The male was swept in a similar habitat, but it cannot be determined whether it was swept from trees.