Peucobius fulvus Townes, 1971, by original designation.

Peucobius can be distinguished from all other genera of Sisyrostolinae by the combination of the following characters: 1) fore wing without areolet, i.e. vein 3rs-m absent (Fig. 18) (areolet present in Brachyscleroma); 2) tarsal claws simple (pectinate in Laxiareola); 3) anterior transverse carina of propodeum present (Fig. 3) (carina absent in Melanodolius and some species of Erythodolius); 4) clypeus unspecialized, evenly rounded in profile, without a transverse ridge, medial point or multiple or medial crenulations (Figs 5, 15) (transverse ridge present in Lygurus; medial point present in some species of Erythrodolius; medial crenulations present in some species of Erythrodolius and Icariomimus).

Within Sisyrostolinae, Peucobius has the smallest species with fore wing length 2.5–3.0 mm, while the genus with the next smallest species, Lygurus, has fore wing length 4.0–5.0 mm, and some other genera are much larger (e.g., 7.0–19.0 mm in Erythrodolius and 17.0–30.0 mm in Melanodolius).

Small insects with fore wing length 2.5–3.0 mm. Head and mesosoma mostly finely granulate to subpolished, impunctate or partly with fine punctures. Head, in dorsal view, with gena strongly rounded posterior to eyes. Clypeus wide, 2.5–3.5 times as broad as long, lenticular, weakly convex, more or less flat medially, with a row of long fine setae on lower margin. Mouthparts short, unspecialized; maxillary and labial palp formula 5+4. Mandible bidentate, with teeth subequal by length or either upper or lower tooth somewhat longer than other. Malar space 0.8–1.0 times as long as basal mandibular width, with scabrous area between eye and mandibular base. Flagellum filiform, with 14–17 flagellomeres. Epomia absent. Notaulus short or absent. Scutellum with lateral longitudinal carinae very short. Sternaulus absent or as weak impression ventrolaterally in anterior part of mesopleuron. Epicnemial carina present. Posterior transverse carina of mesopleuron absent. Propodeum more or less fully carinate (as in Fig. 3), sometimes carinae partly obliterated. Fore wing as in Fig. 18; areolet absent, pterostigma relatively large, vein 2m-cu with one large bulla. Hind wing with nervellus (cu1&cu-a) intercepted below centre. Legs slender; fore tibia with a tooth-like projection on distal outer side; tarsal claws not pectinate. First metasomal tergite 1.8–2.5 times as long as posteriorly broad, with large glymma at base. Second tergite transverse; thyridum (if discernible) very small, oval, at base of tergite 2. Laterotergites 2 and 3 not separated by crease. Ovipositor long and slender, weakly upcurved, slightly swollen before apex (Fig. 11).

In addition to two previously known Nearctic species of Peucobius, one species from Central Mexico and one from Japan are described. A distribution map (Fig. 27) of three North American species and identification key to the four species of Peucobius occurring in the world are given below. We also provide a key to a new species of Peucobius discovered from the East Palaearctic region and two species of the morphologically similar genus Lygurus.

The new species from Mexico differs well from two other North American species, P. fulvus and P. piceus (see the key below). Peucobius fulvus and P. piceus are known to us from their original descriptions (Townes 1971) and several specimens from USA and Canada. The length of mandibular teeth is found to work well for distinguishing these morphologically very similar species from each other, while the two features provided by Townes (1971), i.e. sculpture of mesoscutum and colouration of hind coxa, are less reliable and therefore must be used with caution.

The specimens from Maryland were swept from Pinus virginiensis [P. virginiana Mill.] with staminate cones (Townes 1971: 31).

Figures 1–3. 

Peucobius fulvus, female (Canada, Ontario) (1) and P. piceus, female (USA, Colorado) (2, 3). 1, 2 habitus, lateral view 3 propodeum, dorsal view.

1 female (CNC), Canada, Ontario, Spencerville, Limerick Forest, 29.V.1956, coll. W.R.M. Mason (det. V. Vikberg, 2004). 1 female (paratype, ZISP), USA, Maryland, Takoma Park, 25.IV.1942, coll. H. & M. Townes.

Canada (Ontario) (new country and provincial record for genus), USA (Maryland, Michigan, North Carolina) (Townes 1971).

Peucobius bennetti sp. nov. differs from the two other North American species, P. fulvus and P. piceus, by having the frons with a sharp longitudinal carina between the antennal sockets (weakly convex or with rounded longitudinal swelling in P. fulvus and P. piceus), the occipital carina completely absent in the lower half of the head (complete, or sometimes indistinct near the hypostomal carina in P. fulvus and P. piceus), deep notaulus (absent or very shallow in P. fulvus and P. piceus), area basalis of propodeum substituted by a longitudinal keel (Fig. 10) (distinct in P. fulvus and P. piceus, see Fig. 3), and black and yellow body (Fig. 4), while in P. fulvus and P. piceus the body is paler with yellowish markings less contrasting (Figs 1, 2).

Figures 4–11. 

Peucobius bennetti sp. nov., holotype female 4 body, lateral view 5 head, front view 6 clypeus and mandibles, antero-ventral view 7 head and mesoscutum, dorsal view 8 mesosoma and base of metasoma, lateral view 9 fore wing 10 propodeum, dorsal view 11 apex of ovipositor, lateral view.

Peucobius bennetti sp. nov. also differs from the Eastern Palaearctic P. shimizui sp. nov. by having a shorter metacarpus (R1) of the fore wing, ending just behind the radial cell (Fig. 9), while in P. shimizui sp. nov. the metacarpus (R1) extends well beyond the radial cell (Fig. 18).

Female. Body length 4.1 mm. Fore wing length 3.0 mm.

Head with gena strongly rounded posterior to eyes (Fig. 7); gena in dorsal view 0.75 times as long as eye width. Clypeus 3.5 times as broad as long (Fig. 6), more or less flat medially and with rounded transverse ridge laterally, smooth, with fine punctures in upper half, with a row of long fine setae on lower margin. Mouthparts short; maxillary palp with 5 palpomeres, palpomeres 4 and 5 short, distinctly shorter than palpomeres 2 and 3; labial palp with 4 short palpomeres. Mandible with lower tooth slightly longer than the upper (Fig. 6). Malar space about 0.8 times as long as basal mandibular width, with broad scabrous area between eye and mandibular base. Flagellum with 17 flagellomeres, filiform; three basal flagellomeres 2.5–2.8 times as long as broad; subapical flagellomeres subsquare. Face with conspicuous median swelling, with short and narrow longitudinal furrow on this swelling, with fine and sharp punctures on smooth background laterally, and smooth and almost impunctate centrally on median swelling. Frons with short and sharp longitudinal carina between antennal sockets (just above groove on median swelling); polished and impunctate medially, with fine and sharp punctures laterally. Vertex and gena polished, with very fine setiferous punctures. Occipital carina thin and sharp in upper half of head, evenly convex mediodorsally, and obliterated in lower part (completely absent below level of eye midline).

Mesoscutum polished, centrally almost impunctate, with scattered very fine punctures anteriorly and laterally (Fig. 7). Notaulus present on anterolateral side of mesoscutum, short and deep. Scutellum polished, almost impunctate. Mesopleuron subpolished, dull, with very fine inconspicuous punctures in lower part. Sternaulus as weak impression ventrolaterally in anterior part of mesopleuron. Epicnemial carina extending somewhat above level of lower corner of pronotum, with upper end not reaching anterior margin of mesopleuron and slighty curved backwards. Propodeal spiracle separated from pleural carina by almost one times its own maximum diameter. Propodeum almost entirely covered with weak irregular wrinkles, its carinae partly indistinct; area basalis substituted by a single, longitudinal carina; areola about as long as broad, pointed anteriorly, contiguous with area petiolaris posteriorly (Fig. 10).

Fore wing as in Fig. 9. Vein 2rs-m long, somewhat longer than abscissa of M between 2rs-m and 2m-cu. Metacarpus (R1) very short, ending just behind the distal end of radial cell. Hind wing with nervellus (cu1&cu-a) intercepted in lower 0.45. Legs moderately slender. Fore tibia with long tooth on distal outer side. Hind tibia with two short spurs which are slightly curved at apex.

First metasomal tergite 1.8 times as long as posteriorly broad, with large glymma in basal half (Fig. 8); dorsally tergite 1 polished, finely striate in basal half. Second tergite distinctly transverse, 0.65 times as long as anteriorly broad. Tergites 2 to 6 dorsally highly polished and almost glabrous (with row of fine setae at hind margins), laterally tergites 2 and 3 with rather dense setae and following tergites laterally with sparse setae. Ovipositor slightly swollen before apex and tapered to a point posterior to swelling (Fig. 11); sheath as long as fore wing, or 3.0 times as long as hind tibia.

Head predominantly black; clypeus, face, frontal orbits (extending above to level of hind end of lateral ocelli) and lower third of gena yellow (Figs 4, 5, 7); median third of gena brownish. Mouthparts and mandible (except brownish black teeth) yellow. Antenna black, scape and pedicel ventrally brownish yellow. Mesosoma black; propleuron and front margin of pronotum dark brown (Fig. 8). Tegula yellow. Pterostigma brown with yellowish spot at base (Fig. 9). Fore leg with coxa and trochanters yellow (coxa slightly darkened at extreme base); femur, tibia and tarsus brownish yellow (femur apically yellowish). Mid leg predominantly brownish yellow with coxa extensively darkened with brown and tarsus infuscate. Hind leg with coxa almost entirely brownish black (except pale brown extreme apex), trochanters and femur brownish yellow with extensive dark brown markings on dorsal side, and tibia and tarsus more or less entirely brownish yellow. Tergite 1 black. Metasoma posterior to first tergite dorsally and laterally dark brown (anteriorly) to brown and yellow (posteriorly), ventrally and on hind margins of tergites yellow (Fig. 4). Ovipositor sheath dark brown basally to black apically.

Male. Unknown.

The species is named in honour of the Canadian expert in Ichneumonidae, Andrew M.R. Bennett (CNC).

Holotype female (UNAM), Mexico, Tlaxcala, Nanacamilpa, Ejido Los Búfalos, 19°28'N, 98°35'W, bosque pino-encino (Pinus + Quercus forest), 2830–2900 m, Malaise trap, 4.IV–3.V.2016, coll. Y. Marquez & A. Contreras.

Mexico (Tlaxcala).

The specimens from Utah were swept from Pinus contorta Douglas bearing staminate cones, and the specimens from California were probably swept from Pinus monophylla Torr. & Frém. (Townes 1971: 30).

1 female (CNC), USA, Colorado, Nederland, 8500 ft (= 2590 m), 18.VI.1961, coll. W.R.M. Mason (det. V. Vikberg, 2004).

USA (California, Colorado, New Mexico, Utah).

The species was collected on Pinus densiflora in spring period together with a large quantity of individuals of Gelanes spp. (Tersilochinae).

This species differs from the three Nearctic species in having a longer metacarpus (R1) of the fore wing (Fig. 18) (ending just behind the radial cell in all other species, see Figs 1, 2, 9).

Figures 12–17. 

Peucobius shimizui sp. nov., holotype (11, 13–15) and paratype (12, 16) females 12 habitus, lateral view 13 antenna 14 head, dorsal view 15 head, front view 16 head and mesosoma, lateral view 17 propodeum, dorsal view.

Female. Body length 2.8 mm. Fore wing length 2.6 mm.

Head with gena strongly rounded posterior to eyes (Fig. 14); gena in dorsal view 0.65 times as long as eye width. Clypeus 3.3 times as broad as long (Fig. 15), very weakly convex, smooth, with fine punctures in upper 0.4, with a row of long fine setae on lower margin. Mouthparts short; maxillary palp with 5 palpomeres, palpomeres 4 and 5 short, distinctly shorter than palpomeres 2 and 3; labial palp with 4 short palpomeres. Mandible with lower tooth distinctly broader and somewhat longer than upper (Fig. 15); both teeth in holotype and paratype very obtuse (rounded apically), possibly abraded. Malar space as long as basal mandibular width, with broad scabrous area between eye and mandibular base. Flagellum with 15 flagellomeres, filiform; flagellomeres 2 to 4 about 2.6 times and subapical flagellomeres 1.1–1.3 times as long as broad. Face with weak median swelling and small median tubercle in upper part of this swelling, without longitudinal furrow; face with very fine punctures on smooth background, smooth and impunctate centrally on median swelling. Frons without ridge between antennal sockets, with very fine (partly indistinct) punctures on smooth background, laterally slightly scabrous. Vertex and gena polished, with very fine setiferous punctures. Occipital carina thin, complete, evenly convex mediodorsally.

Mesoscutum and scutellum subpolished, with very fine punctures. Notaulus present on anterolateral side of mesoscutum, weak, with more or less distinct longitudinal wrinkle. Mesopleuron scabrous, impunctate and dull in upper part; with fine punctures on more or less smooth background in lower part. Sternaulus absent. Epicnemial carina extending to about level of lower corner of pronotum, with upper end not reaching anterior margin of mesopleuron. Propodeal spiracle adjacent to pleural carina in holotype and separated from this carina by half diameter of spiracle in paratype. Propodeum scabrous, weakly shining; area basalis small, confluent with areola; areola separated posteriorly from area petiolaris by very weak wrinkle (Fig. 17).

Wings as in Fig. 18. Vein 2rs-m long, much longer than abscissa of M between 2rs-m and 2m-cu. Metacarpus (R1) short, projecting somewhat behind distal end of radial cell. Hind wing with nervellus (cu1&cu-a) intercepted in lower 0.35. Legs moderately slender. Fore tibia with distal outer end pointed (this tooth-like projection shorter than in P. bennetti). Hind tibia with two short straight spurs.

Figures 18–20. 

Peucobius shimizui sp. nov., holotype female 18 wings 19 metasoma, dorsal view 20 ovipositor, lateral view.

First metasomal tergite twice as long as posteriorly broad, with large glymma in basal half and spiracle in basal 0.4 (Fig. 19). Second tergite distinctly transverse, 0.7 times as long as anteriorly broad. All metasomal tergites dorsally polished and almost glabrous (with a row of fine setae at hind margins), tergite 2 and following tergites with setae laterally. Ovipositor slightly swollen before apex and tapered to a point posterior to swelling (Fig. 20); sheath 0.65–0.7 times as long as fore wing, or about 3.5 times as long as hind tibia.

Head predominantly yellow; face and frons medially, vertex and upper part of gena yellowish orange; interocellar area, vertex medially and upper part of occiput blackish (Figs 14, 15). Mouthparts and mandibles (except dark reddish-brown teeth) yellow. Antenna dark brown, scape and pedicel ventrally pale brown. Mesosoma predominantly yellowish orange (Fig. 16); metanotum and propodeum dark reddish brown to black; scutellum laterally and metapleuron darkened with reddish brown; mesoscutum with more or less distinct reddish brown or dark brown marks anteriorly, centrally and posteriorly. Tegula yellow. Pterostigma pale brown (Fig. 18). Legs rather uniformly yellowish orange to brownish orange, hind coxa somewhat darker (with more intense brownish orange colouration). Tergite 1 dark brown. Metasoma posterior to first tergite dark brown dorsally, brown laterally and yellow ventrally; tergites with pale yellow bands on posterior margins dorsally, pale band very narrow on tergite 2 and broader on following tergites (Fig. 19). Ovipositor sheath blackish.

Figures 21–26. 

Lygurus marjoriae (21–24) and L. townesi (25, 26), females 21 habitus, lateral view 22 lower part of head, antero-ventro-lateral view 23, 25 head, dorsal view 24 metasoma, lateral view 25 ovipositor, lateral view 26 head, front view.

Male. Unknown.

The two specimens are almost identical in size, structure and colouration.

The species is named in honour of the collector of the type material, Japanese expert in Ichneumonidae, So Shimizu (Kobe University, Japan).

Holotype female (NIAES), Japan, Honshu I., Kantō Reg., Ibaraki Pref., Kasama City, Hizawa, 36°24'39.3"N, 140°15'6.8"E, ca. 90 m, sweeping on Pinus densiflora, 28.IV.2017, coll. So Shimizu.

Paratype. 1 female (NIAES), same data as holotype.

Japan (Honshu I.).

Figure 27. 

Distribution map of P. fulvus (red), P. bennetti sp. nov. (blue) and P. piceus (green) in North America.