JHR 95: 245-260 (2023) ger, JOURNAL OF eeertennscnn no
doi: 10.3897/jhr.95.98222 RESEARCH ARTICLE () Hymenopter a
https://jhr.pensoft.net The Inarational Society of Hymenoptersts, RESEARCH

Taxonomy of the genus Peucobius Townes
(Hymenoptera, Ichneumonidae, Sisyrostolinae)

Andrey I. Khalaim'’, Enrique Ruiz-Cancino', Juana Maria Coronado-Blanco!

| Facultad de Ingenieria y Ciencias, Universidad Auténoma de Tamaulipas, Ca. Victoria, Tamaulipas, Mexico
2 Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia

Corresponding author: Andrey I. Khalaim (akhalaim@gmail.com)

Academic editor: Gavin Broad | Received 1 December 2022 | Accepted 8 February 2023 | Published 24 February 2023
https://zoobank. org/99C6279A-FA04-4E86-8AC6-ED33C9FD87B3

Citation: Khalaim AI, Ruiz-Cancino E, Coronado-Blanco JM (2023) Taxonomy of the genus Peucobius Townes
(Hymenoptera, Ichneumonidae, Sisyrostolinae). Journal of Hymenoptera Research 95: 245-260. https://doi.
org/10.3897/jhr.95.98222

Abstract

The genus Peucobius Townes previously comprised two species occurring in the Nearctic region: P fulvus
Townes and P piceus Townes. In the current study we revise this genus, transfer it to the subfamily Sisyros-
tolinae (comb. nov.), and describe two new species — P bennetti Khalaim & Ruiz-Cancino, sp. nov. from
Central Mexico and P shimizui Khalaim, sp. nov. from Japan. The genus Lygurus Kasparyan occurring in
Russian Far East and Taiwan is morphologically similar to Peucobius; characters for distinguishing these
two genera are provided for the first time with the use of colour photographs. Identification keys to four
world species of Peucobius, and to species of Lygurus and Peucobius occurring in the East Palaearctic region,
are provided. We suggest that species of Peucobius are associated with xyelid sawflies (Xyelidae) whose

larvae feed in staminate pine cones.

Resumen

El género Peucobius Townes previamente incluia dos especies en la regidn Neartica: P fulvus Townes y
P. piceus Townes. En el presente articulo se revisa el género, se transfiere a la subfamilia Sisyrostolinae
(comb. nov.) y se describen dos especies nuevas — P bennetti Khalaim & Ruiz-Cancino, sp. nov. de la zona
central de México y P shimizui Khalaim, sp. nov. de Japon. El género Lygurus Kasparyan que ocurre en el
Lejano Oriente Ruso y en Taiwan es similar morfoldgicamente a Peucobius; se sehalan por primera vez las
caracteristicas que los distinguen, incluyendo fotografias a color. Se elaboraron las claves para las cuatro
especies de Peucobius del mundo, y las de las especies de Lygurus y Peucobius que ocurren en la regién
Paleartica Oriental. Se sugiere que las especies de Peucobius estan asociadas con moscas sierra (Xyelidae),

cuyas larvas se alimentan en conos estaminados de pinos.

Copyright Andrey I. Khalaim et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

246 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Keywords

Japan, key, Lygurus, Mexico, Nearctic region, new combination, new species, North America, parasitoids

Introduction

The genus Peucobius Townes was described in the subfamily Phrudinae for two Nearctic
species (Townes 1971: 29), and no further works on this genus were published for almost
the following forty years (Yu et al. 2016), until a phylogenetic revision of the family
Ichneumonidae by Quicke with co-authors (Quicke et al. 2009: 1354) in which the
genus Peucobius and six other “microphrudine” genera (Astrenis Forster, Earobia Townes
& Townes, Notophrudus Porter, Phaestacoenitus Smits van Burgst, Phrudus Forster and
Pygmaeolus Hellén) were transferred to Tersilochinae s.l. on the basis of a combined mo-
lecular and morphological analysis. Five other genera previously treated in Phrudinae
(Brachyscleroma Cushman, Erythrodolius Seyrig, Icariomimus Seyrig, Lygurus Kasparyan
and Melanodolius Saussure) were placed within the resurrected subfamily Brachysclero-
matinae Townes (Quicke et al. 2009: 1354), and one more genus, Laxiareola Sheng &
Sun, was described afterwards from Oriental China (Sheng and Sun 2011). Subsequently,
Bennett with co-authors (Bennett et al. 2013) revised the genus Evythrodolius and estab-
lished the subfamily name Sisyrostolinae Seyrig instead of Brachyscleromatinae Townes
due to the priority of Seyrig’s name. They also pointed out that not all former phrudine
genera were included in the analysis of Quicke et al. (2009), and therefore some of the
omitted genera (e.g., Notophrudus and Peucobius) could end up being more closely related
to Sisyrostolinae than the Phrudus group of genera (Bennett et al. 2013: 425-426).

Recently, Bennett with co-authors (Bennett et al. 2019) performed a combined
morphological and molecular phylogenetic analysis of Ichneumonidae, and in both
combined analyses Peucobius fulvus Townes was sister to Erythrodolius calamitosus Sey-
rig (Sisyrostolinae), not Phrudus sp. (Tersilochinae s.l.) which would support the move
of Peucobius to Sisyrostolinae (Bennett et al. 2019: 116-118). However, the mono-
phyly of the subfamily Sisyrostolinae was not confirmed as Brachyscleroma did not
cluster with Peucobius+ Erythrodolius.

The aims of this study are to revise new material of Peucobius, describe two new
species from Mexico and Japan, and discuss the relationships of Peucobius to Sisyros-
tolinae and the Phrudus group of Tersilochinae. Identification keys to world species of
Peucobius, and to East Palaearctic species of Peucobius and the morphologically similar

genus Lygurus will be provided.

Materials and methods

The specimens examined in this study were borrowed from or deposited in the fol-
lowing collections: Instituto de Biologia, Universidad Nacional Auténoma de México,

Taxonomy of Peucobius 247

D.E, México (UNAM), the National Institute for Agro-Environmental Sciences,
Tsukuba, Japan (NIAES), Canadian National Collection of Insects, Ottawa, Ontario,
Canada (CNC), and the Zoological Institute of the Russian Academy of Sciences, St.
Petersburg, Russia (ZISP). Photographs of Lygurus spp. (Figs 21-26) were taken from
non-type females from the Russian Far East deposited in ZISP.

Morphological terms follow Broad et al. (2018). Wings of P shimizui sp. nov.
(Fig. 18) were slide-mounted using Solakryl BMX. Layer photographs were taken in
ZISP, with a Canon EOS 70D digital camera attached to an Olympus SZX10 stereom-
icroscope. Partly focused images were assembled with Helicon Focus Pro 6 software.
Contour map of North America (Fig. 27) was taken from D-maps (2018).

Results and taxonomy

The genus Peucobius is found to belong to the subfamily Sisyrostolinae (comb. nov.) as it
shares the following important morphological features (see Quicke et al. 2009; Bennett
et al. 2013): antenna with cylindrical scape, proboscidial fossa strongly narrowed, hind
wing with vein M+Cu long relative to vein 1-M, metasoma with large laterotergites
and mostly sclerotized sternites, and thin and long ovipositor which is slightly swollen
before the apex and has neither notch nor nodus (Figs 11, 20).

Unlike Tersilochinae s.l., Peucobius possesses unspecialized flagellomeres (in Ter-
silochinae almost all species possess finger-shaped structures at least on several flagel-
lomeres, see Vikberg, Koponen 2000; Khalaim pers. obs.), maxillary and labial palp
formula 5+4 (in Tersilochinae this formula is usually 4+3, though in microphrudines
genera it is 5+4) and fore tibia with a tooth on the distal outer side (in Tersilochinae
distal end of fore tibia is unspecialized, i.e. without tooth).

Within Sisyrostolinae, Peucobius is very similar to the small East Palaearctic and
Oriental genus Lygurus Kasparyan from which it can be distinguished by the following
characters: laterotergite 2 not separated by a crease; clypeus weakly convex and without
a transverse ridge (Fig. 15); and short second metasomal tergite which is about 0.7
times as long as anteriorly broad (Fig. 19). Further taxonomic study of these two gen-
era is required to clarify their generic limits and phylogenetic relationships.

Thus, the subfamily Sisyrostolinae currently comprises seven genera:
Brachyscleroma Cushman (Afrotropical and Oriental regions), Erythrodolius Seyrig
(Afrotropical and Neotropical regions), cariomimus Seyrig (Afrotropical region),
Laxiareola Sheng & Sun (Oriental region), Lygurus Kasparyan (Eastern Palaearctic
and Oriental regions), Melanodolius Saussure (Afrotropical) and Peucobius Townes
(Holarctic region) (Yu et al. 2016).

Genus Peucobius Townes, 1971

Type species. Peucobius fulvus Townes, 1971, by original designation.

248 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Comparative diagnosis. 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 Lygu-
rus; 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).

Description. Small insects with fore wing length 2.5-3.0 mm. Head and meso-
soma mostly finely granulate to subpolished, impunctate or partly with fine punc-
tures. 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, unspe-
cialized; maxillary and labial palp formula 5+4. Mandible bidentate, with teeth sub-
equal 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 mesopleu-
ron 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 (cul &cu-a) inter-
cepted 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; thyri-
dum (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).

Remarks. 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

Taxonomy of Peucobius 249

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.

Key to world species of Peucobius

1

Frons with short but distinct ridge between antennal sockets. Propodeum
with area basalis substituted by a single, longitudinal, median carina; areola
pointed anteriorly (Fig. 10). Mesopleuron entirely black (Fig. 8). Mexico.....
eR Stats U0 SAA SR vaceltn' Sacee alin SM Mane e Se esas aa aS und a P. bennetti sp. nov.
Frons without longitudinal ridge between antennal sockets. Propodeum with
area basalis distinct and more or less contiguous with areola (Fig. 3). Meso-
pleuron with subtegular ridge and area below sternaulus yellow or reddish
Oran (HSS, Dae ese nceaseteemas gates se been pauisnuie tte Siteeiens <seelacdtmtewa Sedoca peaihuen dete 2
Metacarpus (R1) of fore wing ending significantly behind radial cell (Fig. 18).
Metasoma predominantly brownish black (Fig. 12). East Palaearctic region
Eo cn Pevere pe es Oe eee ies a bene nin ie eran taco eri a ete ye P. shimizui sp. nov.
Metacarpus (R1) of fore wing ending just beyond radial cell (Figs 1, 2). Meta-
soma predominantly reddish orange (Fig. 1) or brown (Fig. 2). Nearctic re-
(SAL OTE AG RA ce ARREST Te APIS RN ANG REL i a NEA AEA UOT ah RS 3
Mandible with lower tooth subequal to, or slightly longer than the upper
tooth. Mesoscutum centrally dull. Hind coxa yellow or pale brown (Fig. 1)....
Mold Stench an act Hae tei atetcetl op bet cvstus, Mlatlaebetnald cine ebiuw tia Sekar P. fulvus Townes
Mandible with lower tooth distinctly longer than the upper tooth. Mesoscu-
tum centrally polished. Hind coxa darkened with brown or black (Fig. 2) ....
epee hae ere er rere ieee RETO NRT POE HM NOR TART P. piceus Townes

Key to Lygurus and Peucobius species occurring in East Palaearctic region

1

Second tergite very short, 0.65 times as long as anteriorly broad (Fig. 19); lat-
erotergite 2 not separated by crease (as in Fig. 8). Flagellum of female with 15
flagellomeres (Fig. 13). Clypeus weakly convex, without transverse ridge (Fig.
15). Ovipositor sheath 0.7 times as long as body (Fig. 12). Body yellowish orange
and black (Fig. 12). Fore wing length about 2.6 mm............ P. shimizui sp. nov.
Second tergite distinctly elongated, about 1.5 times as long as anteriorly
broad; laterotergite 2 separated by sharp crease (Fig. 24). Flagellum of female
with 19-24 flagellomeres. Clypeus with transverse ridge (Fig. 22). Ovipositor
sheath longer than body (Fig. 21). Body almost entirely black (Fig. 21). Fore
inealeno the: OH. Uriii seat eoae eee oats eter t sn asten wakct amateur 2
Propodeum with areola distinctly transverse. Ovipositor sheath 1.4 times as long
as body. Russian Far East (Kasparyan 1983).......... L. townesi Kasparyan, 1983
Propodeum with areola somewhat elongated. Ovipositor sheath 1.1 times as
long as body (Fig. 21). Russian Far East and Taiwan (Chiu and Wong 1987:
4; Kasparyan and Khalaim 2007: 564)... L. marjoriae Chiu, 1987

250 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Peucobius fulvus Townes, 1971
Fig. 1

Remarks. ‘The specimens from Maryland were swept from Pinus virginiensis [P virgini-
ana Mill.] with staminate cones (Townes 1971: 31).

Material examined. 1 female (CNC), Canapa, 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.

Distribution. Canada (Ontario) (new country and provincial record for genus),

USA (Maryland, Michigan, North Carolina) (Townes 1971).

Figures 1-3. Peucobius fulvus, female (Canada, Ontario) (I) and P piceus, female (USA, Colorado) (2,

3). 1, 2 habitus, lateral view 3 propodeum, dorsal view.

Taxonomy of Peucobius 251

Peucobius bennetti Khalaim & Ruiz-Cancino, sp. nov.
https://zoobank.org/8AC4CA3C-0 DE3-4CF3-899C-D9CF76BD0730
Figs 4-11

Comparison. 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).

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 ra-
dial cell (Fig. 9), while in P shimizui sp. nov. the metacarpus (R1) extends well beyond
the radial cell (Fig. 18).

Description. 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 punc-
tures 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. Flagel-
lum 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 me-
dian swelling. Frons with short and sharp longitudinal carina between antennal sock-
ets (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 medi-
odorsally, and obliterated in lower part (completely absent below level of eye midline).

Mesoscutum polished, centrally almost impunctate, with scattered very fine punc-
tures anteriorly and laterally (Fig. 7). Notaulus present on anterolateral side of mes-
oscutum, short and deep. Scutellum polished, almost impunctate. Mesopleuron sub-
polished, 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

252 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Figures 4-I 1. 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 II apex of ovipositor, lateral view.

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 in-
distinct; 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 be-
tween 2rs-m and 2m-cu. Metacarpus (R1) very short, ending just behind the distal end

Taxonomy of Peucobius 259

of radial cell. Hind wing with nervellus (cul &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 glym-
ma 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; propleu-
ron 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 (fe-
mur apically yellowish). Mid leg predominantly brownish yellow with coxa extensively
darkened with brown and tarsus infuscate. Hind leg with coxa almost entirely brown-
ish 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.

Etymology. The species is named in honour of the Canadian expert in Ichneumo-
nidae, Andrew M.R. Bennett (CNC).

Material examined. Holotype female (UNAM), Mexico, Tlaxcala, Nanacamilpa,
Ejido Los Bufalos, 19°28'N, 98°35'W, bosque pino-encino (Pinus + Quercus forest),
2830-2900 m, Malaise trap, 4.1V—3.V.2016, coll. Y. Marquez & A. Contreras.

Distribution. Mexico (Tlaxcala).

Peucobius piceus Townes, 1971

Figs!23 3

Remarks. ‘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).

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

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

254 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Peucobius shimizui Khalaim, sp. nov.
https://zoobank.org/98ACA320-45 15-4FAA-9419-B542B04C0154
Figs 12-20

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

Comparison. ‘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).

Description. 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; flag-
ellomeres 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 back-
ground, smooth and impunctate centrally on median swelling. Frons without ridge
between antennal sockets, with very fine (partly indistinct) punctures on smooth back-
ground, 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 pre-
sent on anterolateral side of mesoscutum, weak, with more or less distinct longitudinal
wrinkle. Mesopleuron scabrous, impunctate and dull in upper part; with fine punc-
tures 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 (cul &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.

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

Taxonomy of Peucobius 255

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.

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

256 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Figures | 8-20. Peucobius shimizui sp. nov., holotype female 18 wings 19 metasoma, dorsal view 20 ovi-
positor, lateral view.

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.

Male. Unknown.

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

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

Taxonomy of Peucobius 257

eel 26
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.

Material examined. Holotype female (NIAES), Japan, Honshu I., Kanto Reg.,
Ibaraki Pref., Kasama City, Hizawa, 36°24'39.3"N, 140°15'6.8"E, ca. 90 m, sweeping
on Pinus densiflora, 28.1V.2017, coll. So Shimizu.

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

Distribution. Japan (Honshu I.).

258 Andrey I. Khalaim et al. / Journal of Hymenoptera Research 95: 245—260 (2023)

Figure 27. Distribution map of P fulvus (red), P bennetti sp. nov. (blue) and P piceus (green) in
North America.

Discussion

The two Nearctic species described by Townes were collected by sweeping branches of
pines bearing staminate cones (Townes 1971: 29), and P bennetti from Mexico was
collected in pine-oak forest on the same dates and at the same locality as two other
parasitoids, Gelanes horstmanni Khalaim (Tersilochinae) and /diogramma elbakyanae
Khalaim (Tryphoninae), were collected (Khalaim and Ruiz-Cancino 2017). The fourth
species of the genus, P shimizui from Japan, was also collected on Pinus in spring to-
gether with a large quantity of individuals of Gelanes spp. In the body habitus, yellow/
orange and black colour pattern of the body, and possession of a long and thin oviposi-
tor, P bennetti and P shimizui resemble species of Gelanes and Idiogramma very much.

There is no direct host record for any Peucobius species, but genera Gelanes Horst-
mann and /diogramma Forster are typical parasitoids of xyelid sawfly larvae (Xyelidae)
developing in staminate pine cones, and therefore we suggest that the genus Peucobius,

Taxonomy of Peucobius 259

being frequently collected together with Gelanes and Idiogramma species on their host
plants, and being morphologically very similar to these taxa, quite possibly parasitizes
the same host.

Acknowledgements

We are thankful to Alejandro Zaldivar-Riveron (UNAM), So Shimizu (Kobe Univer-
sity, Japan) and Andrew M.R. Bennett (CNC) for loaning specimens, to Dmitri R.
Kasparyan (ZISP) for his comments on the taxonomy of Lygurus, Yulia V. Astafurova
(ZISP) for her assistance in taking colour photographs of Lygurus spp., and to Andrew
M.R. Bennett (CNC), Rikio Matsumoto (Osaka Museum of Natural History, Osaka,
Japan) and Alexandra Viertler (Institute of Ecology and Evolution, University of Bern,
Bern, Switzerland) for reviewing the paper. Sincere thanks to A.M.R. Bennett for his
hard work on the review of the manuscript, valuable remarks and suggestions on the
taxonomy and structure of the paper. The work of the senior author was partly sup-
ported by the Russian State Research Project no. 122031100272-3.

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