Pteromalus briani, 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 : 45-52

Taxon classification Animalia Hymenoptera Pteromalidae

Pteromalus briani sp. n. Figs 1, 2A, B

Type material.

Holotype ♀ Switzerland, Canton Bern, Köniz, Niederwangen, 570 m, 46.92361°N, 7.37266°E, leg. Jacqueline Grosjean, 28-ii-2004, ex pupa 16-iii-2004, host Vanessa atalanta (Linnaeus, 1758) ( Lepidoptera : Nymphalidae ), deposited in NMBE (Baur 2129). The host pupa was collected in sheltered cavity of a pedestrian underpass beneath the highway and railway line in Niederwangen. Paratypes 46 ♀ 2 ♂, emerging from the same host pupa as the holotype, deposited in: 2 ♀ BMNH, 2 ♀ CNC, 2 ♀ ETHZ, 5 ♀ JGC, 2 ♀ LUZN, 2 ♀ MHNG, 2 ♀ NHMV, 19 ♀ (Baur 2408, 2414, 2416, 2418-2421, 2423-2426) 2 ♂ (Baur 2139, 2415) NMBE, 2 ♀ SMNS, 2 ♀ UCR, 2 ♀ USNM, 2 ♀ VVC, 2 ♀ ZFMK. Paratypes 6 ♀ Switzerland, Canton Bern, Reichenbach, Kien, 560 m, 46.6132°N, 7.6854°E, v-2008, leg. Rahel Schnidrig, reared from pupa of Aglais urticae (Linnaeus, 1758) ( Lepidoptera : Nymphalidae ), deposited in: 1 ♀ CNC, 5 ♀ NMBE. According to Schnidrig (pers. comm.), the host was collected as a larva (size about 2.5 mm) and afterwards reared under protected conditions. A total of 40-50 specimens emerged from the pupa but only the paratypes were preserved.

Description, female.

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

Scape: testaceous; pedicel: testaceous, slightly infuscate dorsally; flagellum: brown.

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

Coxae: green; trochanters: testaceous; femora: testaceous; tibiae: testaceous; tarsi: testaceous with fifth segment slightly infuscate; pretarsi: slightly infuscate.

Petiole: green with purplish tinge; gaster: green; gastral terga: one to five with strong purplish tinge.

Sculpture: Head in frontal view: finely reticulate with relatively high dividing septa; clypeus: finely striate (Fig. 1A); area between clypeus and malar sulcus: meshes of reticulation conspicuously enlarged (Fig. 1A).

Mesoscutum: finely reticulate, meshes rather high, areoles small and only moderately enlarged in posterior part of sclerite (Fig. 1D); scutellum: reticulate, meshes about as strong and coarse as on posterior part of mesoscutum, but with a narrow band of smaller areoles in anterior half of median longitudinal line; frenum: reticulate, meshes of similar size to those on scutellum; axilla: reticulate, about as strong as on central part of scutellum; prepectus upper triangular area: reticulate; upper mesepimeron: anteriorly smooth, posterior corner distinctly alutaceous; upper mesepisternum: reticulate, about as strong as on mesoscutum; metapleuron: reticulate, about as strong as on mesepisternum.

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

Median area of propodeum: evenly reticulate, as strong as on mesoscutum (Fig. 1G); inner corner of anterior plica: with a depression, weakly reticulate; nucha: reticulate, as strong as on median area of propodeum; callus of propodeum: reticulate; paraspiracular sulcus: reticulate with few transverse costulae.

Petiole in dorsal view: smooth; gastral terga: smooth and shining, sixth tergum and syntergum alutaceous (Fig. 1H).

Shape and structure: Head in frontal view: subtrapezoid; gena in frontal view: rounded; temple in dorsal view: obtuse (Fig. 1B); forming an angle with occiput of: 120 degrees; occipital carina: absent; torulus position with respect to lower ocular line: distinctly above; lower face in lateral view: flat, receding with respect to upper face: weakly, forming an angle of: 35 degrees; scrobe: narrow, rather shallow; malar sulcus: superficial, but traceable; clypeus, anterior margin: widely and shallowly emarginate, without a slight depression above emarginate edge; gena near mouth: terete; tentorial pit: distinctly visible (Fig. 1A); mouth extension: not conspicuously enlarged; mandibular formula: 4-4.

Antenna (Fig. 1C). Antennal formula: 11263; scape reaching: distinctly above level of vertex; flagellum: filiform; first anellus: strongly transverse; second anellus: strongly transverse; first funicular segment: cylindrical; setae on flagellum: moderately thickly clothed with setae standing out at an angle of 30 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: moderately strongly bent; propodeum in lateral view sloping with respect to dorsal plane of mesoscutum and scutellum at an angle of: 45 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: rounded edge; pronotum posterior margin: thin, shiny strip; notaulus: extremely superficial, hardly traceable, reaching: about half along mesoscutum (Fig. 1D); scutellum in lateral view: moderately convex; scutellum in posterior view: moderately convex; 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: not separated by oblique carina; upper mesepimeron: strongly narrowing below, not reaching base of mesopleuron; propodeum (Fig. 1G): anterior plica: bent inwards in anterior two fifths and strong; posterior plica: present, joining or almost joining anterior plica; orientation of posterior plicae: almost parallel; median carina of propodeum: weakly indicated, irregular; 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: numerous long setae; paraspiracular sulcus: narrow and deep.

Fore wing (Fig. 1E). Fore wing apex with respect to apex of gaster when folded back: distinctly exceeding; basal cell number of setae: 7; basal setal line: complete, with: 6 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: rather thickly pilose; marginal setae: present, short; stigma: subcircular, small; uncus: short.

Femora: moderately slender; metatibia: quite abruptly expanded before the middle (Fig. 1F); metacoxa pilosity, dorsally: bare.

Petiole in dorsal view: conical, in ventral view: open; gaster in dorsal view: ovate, obtusely pointed (Fig. 1G); gastral terga: weakly sunken; posterior margin of first gastral tergum: slightly curved backwards medially; first gastral tergum reaching: two fifths of gaster; tip of hypopygium reaching: slightly beyond middle of gaster; ovipositor sheath: slightly protruding.

Length and body ratios: Body length: 2.3-2.9 mm; mesoscutum breadth: 591-806 µm.

Head breadth to height: 1.2-1.41; head breadth to length: 2.02-2.08; head breadth to mesoscutum breadth: 1.26-1.34; lower face height to head height: 0.5-0.58; POL to OOL: 0.76-0.87; eye height to breadth: 1.3-1.36; eye distance to height: 1.74-1.88; temple length to eye length: 0.35-0.44; malar space to eye height: 0.68-0.76.

Pedicel plus flagellum length to head breadth: 0.72-0.87; scape length to eye height: 0.99-1.04; scape length to breadth: 5.24-5.82; pedicel length to breadth: 1.22-1.54; pedicel length to first funicular segment length: 0.84-1.13; first funicular segment length to breadth: 0.91-1.33; sixth funicular segment length to breadth: 0.85-1.04; first funicular segment breadth to clava breadth: 0.85-1.06; clava length to breadth: 2.01-2.57.

Mesosoma length to mesoscutum breadth: 1.5-1.6; mesoscutum breadth to length: 1.57-1.76; mesoscutum length to scutellum length: 1.03-1.1; propodeum length to scutellum length: 0.57-0.62; plica distance to propodeum length: 1.21-1.31.

Fore wing length to breadth: 2-2.18; marginal vein length to stigmal vein length: 1.51-1.68; postmarginal vein length to stigmal vein length: 0.78-1.01.

Metafemur length to breadth: 3.27-4.47; metatibia length to breadth: 5.61-7.82; metatarsus length to metatibia length: 0.65-0.89.

Gaster length to breadth: 1.17-1.62; gaster length to mesosoma length: 0.82-1.11.

Description, male.

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

Scape: testaceous; pedicel: testaceous, slightly infuscate dorsally; flagellum: testaceous, slightly infuscate dorsally.

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

Coxae: green; trochanters: testaceous; femora: testaceous; tibiae: testaceous; tarsi: testaceous with fifth segment slightly infuscate; pretarsi: slightly infuscate.

Petiole: green with purplish tinge; gaster: green; gastral terga: one to three with an indistinct yellowish spot.

Sculpture: Head in frontal view: finely reticulate with relatively high septae; clypeus: finely striate; area between clypeus and malar sulcus: meshes conspicuously enlarged (Fig. 2A).

Mesoscutum: finely reticulate, meshes rather high, areoles small and only moderately enlarged in posterior part of sclerite; scutellum: reticulate, meshes about as strong and coarse as on posterior part of mesoscutum, but with a narrow band of smaller areoles in anterior half of median longitudinal line; frenum: reticulate, meshes of similar size to those on scutellum; axilla: reticulate, about as strong as on central part of scutellum; prepectus upper triangular area: reticulate; upper mesepimeron: anteriorly smooth, posterior corner distinctly alutaceous; upper mesepisternum: reticulate, about as strong as on mesoscutum; metapleuron: reticulate, about as strong as on mesepisternum.

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

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

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

Shape and structure: Head in frontal view: subtrapezoid; gena in frontal view: rounded; temple in dorsal view: obtuse; forming an angle with occiput of: 120 degrees; occipital carina: absent; torulus position with respect to lower ocular line: distinctly above; lower face in lateral view: flat, receding with respect to upper face: weakly, forming an angle of: 35 degrees; scrobe: narrow, rather shallow; malar sulcus: superficial, but traceable; clypeus, anterior margin: widely and shallowly emarginate, without a median depression above emarginate edge; gena near mouth: terete; tentorial pit: distinctly visible; mouth extension: not conspicuously enlarged (Fig. 2A); mandibular formula: 4-4.

Antenna (Fig. 2B). Antennal formula: 11263; scape reaching: distinctly above level of vertex; flagellum: filiform; first anellus: strongly transverse; second anellus: strongly transverse; setae on flagellum: thickly clothed with setae standing out at an angle of 40 degrees, length of setae less 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: moderately strongly bent; propodeum in lateral view sloping with respect to dorsal plane of mesoscutum and scutellum at an angle of: 50 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: rounded edge; pronotum posterior margin: thin, shiny strip; notaulus: extremely superficial, hardly traceable, reaching: about half along mesoscutum; scutellum in lateral view: moderately convex; scutellum in posterior view: moderately convex; 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: separated by a fine oblique carina; upper mesepimeron: strongly narrowing below, not reaching base of mesopleuron; anterior plica: bent inwards in anterior two fifths and strong; posterior plica: present, joining anterior plica; orientation of posterior plicae: almost parallel; median carina of propodeum: weakly indicated, irregular; 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: numerous long setae; paraspiracular sulcus: narrow and deep.

Fore wing apex with respect to apex of gaster when folded back: distinctly exceeding; basal cell number of setae: 6; basal setal line: complete, with: 8 setae; cubital setal line: incomplete, with: 4 setae; costal cell pilosity on dorsal side: bare; costal cell pilosity on lower side: numerous setae in distal half and a complete setal line extending to base; speculum on upper side: bare, widely open below; fore wing disc: rather thickly pilose; marginal setae: present, short; stigma: subcircular, small; uncus: short.

Femora: moderately slender; metatibia: quite abruptly expanded before the middle; metacoxa pilosity, dorsally: bare.

Petiole in dorsal view: conical, in ventral view: open; gaster in dorsal view: ovate; gastral terga: weakly sunken.

Length and body ratios: Body length: 2.7 mm; mesoscutum breadth: 682-684 µm.

Head breadth to height: 1.46-1.47; head breadth to length: 2.02-2.03; head breadth to mesoscutum breadth: 1.3; lower face height to head height: 0.59-0.6; POL to OOL: 0.89-0.96; eye height to breadth: 1.29-1.3; eye distance to height: 1.78; temple length to eye length: 0.39-0.43; malar space to eye height: 0.58-0.61.

Pedicel plus flagellum length to head breadth: 0.84; scape length to eye height: 0.97-0.98; scape length to breadth: 4.89-5.15; pedicel length to breadth: 1.37; pedicel length to first funicular segment length: 0.85-0.96; first funicular segment length to breadth: 1.27-1.57; sixth funicular segment length to breadth: 1.02-1.05; first funicular segment breadth to clava breadth: 0.91-0.98; clava length to breadth: 2.44-3.13.

Mesosoma length to mesoscutum breadth: 1.63-1.64; mesoscutum breadth to length: 1.48-1.5; mesoscutum length to scutellum length: 1.08-1.12; propodeum length to scutellum length: 0.55-0.59; plica distance to propodeum length: 1.21-1.39.

Fore wing length to breadth: 2-2.02; marginal vein length to stigmal vein length: 1.39-1.56; postmarginal vein length to stigmal vein length: 0.84-0.93.

Metafemur length to breadth: 4.23-4.62; metatibia length to breadth: 7.16-7.35; metatarsus length to metatibia length: 0.72-0.74.

Gaster length to breadth: 1.68-1.71; gaster length to mesosoma length: 1-1.01.

Comment.

Close examination of the expanded metatibia under a stereomicroscope did not reveal any distinctive characteristics compared to the “normal”, i.e. unexpanded, metatibia of the other Pteromalus species. It should be noted that for some of the specimens reared from Aglais urticae the expansion is slightly less abrupt than shown in Fig. 1F.

Diagnosis.

The female of Pteromalus briani sp. n. keys out in Graham (1969) via couplets 1, 2, 7-9, 11, 12, 14, 49, 52-57, 88-90 (alternatively couplets 49, 70, 72, 74, 78, 79, 84, 88-90) to Pteromalus smaragdus Graham. The male keys out via couplets 1-3, 5, 7, 10, 11, 14-19, 40, 44, 45, 54-56, 65 to Pteromalus semotus and Pteromalus varians [sub Pteromalus grandis ]. The species belongs to a group of species with 4 teeth in both mandibles and a large reticulate nucha (i.e., to Pteromalus sensu stricto of Graham 1969). In this group it is most similar to Pteromalus puparum and Pteromalus squamifer , especially in the structure of the propodeum (compare Figs 1G and 2G). It is distinguished from those and all other species by the following combination of characters: female legs except coxae bright testaceous (Fig. 1F); reticulation between clypeus and malar sulcus with enlarged meshes (Fig. 1A, 2A); POL distinctly less than OOL (Fig. 1B); tentorial pit distinctly visible (Fig. 1A); antenna inserted high on face, lower edge of torulus above the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite (Fig. 1D); scutellum in lateral view moderately convex; metatibia quite abruptly expanded before the middle (Fig. 1F); female gaster obtusely pointed (Fig. 1H), usually less than 1.6 times as long as broad.

Below the most important differences are given for those species with which Pteromalus briani sp. n. might be most easily confounded. Because of the difficulty to identify some of them, a rather large number of taxa either related to Pteromalus puparum or with similar hosts ( Lepidoptera : Papilionidae , Nymphalidae or Pieridae ) has been considered.

Pteromalus apum (Retzius, 1783): female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL greater than OOL; tentorial pit indistinct; antenna inserted less high on face, lower edge of torulus below the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view flattened; metatibia gradually widening towards apex; female gaster acuminate, often more than 1.6 times as long as broad. Source of information: 2 ♀ 2 ♂ from Switzerland in NMBE (Baur 2517-2520), also compared with the key by Askew and Shaw (1997).

Pteromalus bifoveolatus ( Förster, 1861): female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL slightly greater than OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, often more than 1.6 times as long as broad. In addition, the male of Pteromalus bifoveolatus is special in that the mouth is very wide, so that the malar space is much less than 0.1 times as long as eye height (0.58-0.61 in Pteromalus briani sp. n.). Source of information: syntype ♂ in NHMV, 2 ♀ 2 ♂ (Baur 2521-2524) from Switzerland in NMBE.

Pteromalus cassotis Walker, 1847 (syn. Pteromalus archippi Howard, 1889: 1891): female legs except coxae testaceous; reticulation between clypeus and malar sulcus without enlarged meshes; POL about as great as OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, about 1.25 times as long as broad. Source of information: photographs of lectotype ♀ in BMNH, provided by N. Dale-Skey Papilloud; lectotype ♀ of Pteromalus archippi in USNM.

Pteromalus fuscipes (Provancher, 1881): The lectotype is deposited in the Laval University, Quebec, Canada ( Noyes 2015; Huber, pers. comm.), but was not available for examination. The original description (see Provancher 1881: 295) suggests a species with dark legs ("Pattes brunes" = legs brown), which naturally excludes an identity with Pteromalus briani sp. n. Burks (1963: 1262) suggested that Pteromalus fuscipes might be the same as Pteromalus puparum vanessae (see also below).

Pteromalus luzonensis Gahan, 1925: female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL about as great as OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster obtusely pointed, 1.4-1.6 times as long as broad. Source of information: photographs of a syntype ♀ from Luzon, Mount Makiling, provided by the USNM Chalcidoidea type catalog. 5 ♀ 5 ♂ from Assam and Nepal, in BMNH, compared with the original description by Gahan (1925: 99-100).

Pteromalus melitaeae Dzhanokmen, 1998: female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL greater than OOL; tentorial pit indistinct; antenna less high on face, lower edge of torulus slightly below the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, about 2.3 times as long as broad. Source of information: 2 ♀ from Switzerland in NMBE (Baur 2525, 2526), compared with a paratype 1 ♀ in BMNH and the English version of the original description by Dzhanokmen (1998).

Pteromalus platensis Brèthes in Massini, 1913 (syn. Pteromalus caridei Brèthes, 1913: 93, synonymized by De Santis 1967: 197): The name-bearing types are not available for examination ( Noyes 2015). The descriptions of Pteromalus platensis and Pteromalus caridei (see Massini 1913: 517, Brèthes 1913: 93, and Massini and Brèthes 1918, 2. plate), suggest a species with dark femora close to Pteromalus puparum , which thus excludes it from being the same as Pteromalus briani sp. n.

Pteromalus platyphilus Walker, 1874: female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL greater than OOL; tentorial pit indistinct; antenna less high on face, lower edge of torulus distinctly below the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster obtusely pointed, about 1.3 times as long as broad. Source of information: 1 ♀ from Morocco in NMBE (Baur 2527), det. Z. Bouček 1996.

Pteromalus puparum (Linnaeus, 1758): female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL slightly greater than OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster obtusely pointed, rarely more than 1.6 times as long as broad. Source of information: 3 ♀ 2 ♂ from Switzerland in NMBE (Baur 2528-2531, 2549).

Pteromalus puparum vanessae Howard, 1889: Harris (1841: 220-221) originally proposed the specific name "Pteromalus vanessae" but without accompanying description. Hence it has to be considered as a nomen nudum ( Noyes 2015). Howard (1889: 1891-1892) who gave a brief description based on material reared from Nymphalis antiopa (Linnaeus, 1758) (sub Euvanessa antiopa ) and Polygonia interrogationis (Fabricius, 1798) (both Lepidoptera : Nymphalidae ), eventually made the name available. The whereabouts of the syntypes is unknown ( Noyes 2015) and they thus could not be checked. However, Howard (1889) evidently considered Pteromalus puparum vanessae to be only a larger and darker variety of Pteromalus puparum , of which he gave a redescription (p. 1890). The latter is said to have dark legs, which differentiates the species from Pteromalus archippi (= Pteromalus cassotis , see above) with pale legs described by Howard in the same paper (p. 1891). Therefore, Pteromalus puparum vanessae also must have dark legs, which clearly separates it from Pteromalus briani sp. n.

Pteromalus semotus (Walker, 1834): female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL distinctly greater than OOL; tentorial pits indistinct; antenna less high on face, lower edge of torulus slightly below the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, distinctly more than twice as long as broad. Source of information: 1 ♀ from Switzerland in NMBE (Baur 2532), compared with the lectotype ♀ in BMNH.

Pteromalus smaragdus Graham, 1969: female legs except coxae bright testaceous [this is in contrast to the original description, where it is stated on p. 494 that the legs have the same color as Pteromalus procerus (Graham, 1969) which is said to have the femora infuscate (p. 493)]; reticulation between clypeus and malar sulcus without enlarged meshes; POL slightly greater than OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, about 1.3 times as long as broad. Source of information: photographs of holotype ♀ in BMNH, provided by N. Dale-Skey Papilloud.

Pteromalus squamifer (Thomson, 1878): female legs except coxae testaceous (Fig. 2F); reticulation between clypeus and malar sulcus without enlarged meshes (Fig. 2C); POL slightly less than OOL (Fig. 2D); tentorial pit indistinct (Fig. 2C); antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles large and rather strongly enlarged in posterior part of sclerite (Fig. 2E); scutellum in lateral view moderately convex; metatibia gradually widening towards apex (Fig. 2F); female gaster acuminate (Fig. 2H), 1.55-1.6 times as long as broad. As in Pteromalus bifoveolatus , the male has the mouth very large (see Graham 1969: 399, figure 338) and malar space much less than 0.1 times as long as eye height (0.58-0.61 in male Pteromalus briani sp. n., Fig. 2A). Source of information: photographs of lectotype ♀ in LUZM, provided by C. Hansson; 1 ♀ from Italy in NMBE (Baur 2533) and 4 ♀ from Sweden in BMNH (Baur 2545-2548). It should be noted that in the key of Graham (1969: 513-514) couplet 91 to Pteromalus squamifer might be misleading, in that he stated "temples about two thirds as long as eyes". In fact, my measurements on a photograph as well as on the other specimens showed that the temple is at most 0.6 times as long as the eye (Fig. 1C). This value is also strongly depending on how the head is positioned. In another photograph after re-positioning of the same specimen, the ratio was only 0.5!

Pteromalus varians (Spinola, 1808): female femora varying from infuscate to testaceous; reticulation between clypeus and malar sulcus without enlarged meshes; POL distinctly greater than OOL; tentorial pits indistinct; antenna high on face, lower edge of torulus at about the middle between anterior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, distinctly more than twice as long as broad. Source of information: 4 ♀ 1 ♂ from France, Moldavia, and Switzerland in NMBE (Baur 2534-2539), compared with lectotypes of synonyms of Pteromalus varians , that is, ♀ Pteromalus grandis Walker, 1835 and ♀ Pteromalus latipennis Walker, 1835 in BMNH.

Pteromalus vopiscus Walker, 1839: female femora infuscate; reticulation between clypeus and malar sulcus without enlarged meshes; POL slightly greater than OOL; tentorial pit indistinct; antenna high on face, lower edge of torulus at about the middle between an terior margin of clypeus and anterior edge of anterior ocellus; mesoscutum with areoles small and only moderately enlarged in posterior part of sclerite; scutellum in lateral view moderately convex; metatibia gradually widening towards apex; female gaster acuminate, often more than 1.6 times as long as broad. Source of information: 2 ♀ from Switzerland, in NMBE (Baur 2540, 2541). Identification originally based on Graham’s (1995) redescription of the species, however, the specimens were later also compared with specimens from Southern France in BMNH identified by Graham himself.

Etymology.

Following the suggestion of the collector of the new species, Jacqueline Grosjean, Pteromalus briani sp. n. is named after Brian Jones, since the Vanessa atalanta pupa was collected on his birthday. The name “briani” is a noun in the genitive case and need not agree in gender with the generic name.

Biology.

Pteromalus briani sp. n. is a gregarious, primary endoparasitoid of pupae of Nymphalidae ( Lepidoptera ). Currently, Vanessa atalanta and Aglais urticae are known as hosts but the species is likely to attack pupae of other nymphalids or possibly of related families. About 58-60 specimens emerged from the overwintering pupa of Vanessa atalanta (only 51 ♀, 2 ♂ preserved). According to Rahel Schnidrig (pers. com.) about 40-50 specimens emerged from the pupa of Aglais urticae but only 6 ♀ were preserved. The investigation of Schnidrig suggests a koinobiont life history strategy, because the host was collected in an early larval stage (body length 2.5 mm), which was afterwards protected from further parasitization during captive rearing.