JHR 97: 229-239 (2024) ee JOURNAL OF Arevminrcrassen aa

doi: 10.3897/jhr.97.115524 RESEARCH ARTICLE () I Tymenopter a
>

https://jhr.pensoft.net ‘The International Society of Hymenopteriss RESEARCH

First discovery of Plutarchia (Hymenoptera,
Eurytomidae) in Palearctic region, with
description of a new species from South Korea

Duk-Young Park', Seunghwan Lee!”

I [nsect Biosystematics Laboratory, Department of Agricultural Biotechnology, Seoul National University, Seoul,
08826, Republic of Korea 2 Research Institute of Agricultural and Life Sciences, Seoul National University,
Seoul, 08826, Republic of Korea

Corresponding author: Seunghwan Lee (seung@snu.ac.kr)

Academic editor: Petr Jansta | Received 14 November 2023 | Accepted 5 March 2024 | Published 26 March 2024
Attps://zoobank.org/22D 7AF5B-7B43-4136-A6CF-1EE84016E25C

Citation: Park D-Y, Lee S (2024) First discovery of Plutarchia (Hymenoptera, Eurytomidae) in Palearctic region,
with description of a new species from South Korea. Journal of Hymenoptera Research 97: 229-239. https://doi.
org/10.3897/jhr.97.115524

Abstract

The genus Plutarchia is discovered in the Palearctic region for the first time. In this study, we report a
newly described and newly recorded species from South Korea: P fuscipennata sp. nov., and P malabarica
Narendran & Padmasenan, 1990, respectively. The host association of Plutarchia malabarica reared from
leaf-miner flies (Diptera: Agromyzidae) attacking the seeds of Pueraria lobata (Willd.) Ohwi (Fabaceae)
has been unknown until now. A key to the South Korean species and descriptions of the new species are

also provided.

Keywords

Agromyzidae, East Asia, Fabaceae, new species, parasitoid

Introduction

The genus Plutarchia is a relatively small group within the family Eurytomidae and
comprises 13 known species (Noyes 2019). Girault (1925) described this genus
based on P bicarinativentris from Australia. Subsequent species were recorded in the
Palaeotropical region, with one in the Afrotropical region and the others in the Oriental
region. However, this is not known in the Palearctic region.

Copyright Duk-Young Park & Seunghwan Lee. 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.

230 Duk-Young Park & Seunghwan Lee / Journal of Hymenoptera Research 97: 229-239 (2024)

This genus concept has undergone several morphological revisions, with new species
added by Subba Rao (1974), Bougek (1988), Narendran (1994), and Lotfalizadeh et
al. (2007). According to Lotfalizadeh et al. (2007), it has been placed within the genus
Philolema clade based on morphological characters. However, owing to their unique char-
acteristics, such as the projection of the mesopleuron, a procoxa with a large depression,
and the fusion of 1* and 2” gastral tergites with large basal pits, they have maintained an
independent generic name.

The host of Plutarchia is not well known, but Boucéek (1988) suggested that this
genus is a parasitoid of dipterous puparia, particularly Agromyzidae. He pointed out
that P indefensa (Walker) was reared from Melanagromyza sp. (Diptera: Agromyzidae)
in India, P bicarinativentris was found in the pods of Glycine clandestina (Fabaceae)
in Australia, and undescribed species were reared from Ophiomyia phaseoli (Diptera:
Agromyzidae) in Papua New Guinea.

In this study, we report the genus Plutarchia in the Palearctic region for the first
time by the new species and new record from South Korea.

Materials and methods

Adult specimens of Plutarchia fuscipennata, sp. nov., were collected using sweeping
nets, and P malabarica were reared from the puparia of Agromyzidae in the pods
of Pueraria lobata (Willd.) Ohwi (Fabaceae). Most of the specimens were deposited
at the Laboratory of Insect Biosystematics, Seoul National University, and one
specimen of each species was deposited at the National Institute of Biological Re-
sources. [he abbreviations for the depositories of the specimens used in this study
are as follows:

NIBR National Institution of Biological Resources;
SNU Laboratory of Insect Biosystematics, Seoul National University;
ZSIC = Zoological Survey of India, Calcutta, India.

Specimens were examined with an Olympus SZ61 stereomicroscope and photo-
graphed with a DMC 5400 digital camera attached to a Leica Z16 APO motorized
macroscope. Serial images were combined using Zerene Stacker and digitally retouched
using Adobe Photoshop CS6. Most morphological terms follow Lotfalizadeh et al.
(2007) and Delvare et al. (2019).

Morphological abbreviations used in this paper as follows: F1-FX, funiculars 1—X;
MPS, multiporous plate sensilla(e); POL, the distance between posterior ocelli; LOL,
distance between anterior and posterior ocellus; OOL, minimal distance between pos-
terior ocellus and inner orbit; OD, maximum diameter of posterior ocellus; cc, costal
cell; mv, marginal vein; pmv, postmarginal vein; stv, stigmal vein; GT1-GTX, gastral
tergites 1 to X.

First discovery of Plutarchia in Palearctic region, with description of a new species 231

Taxonomy

Plutarchia Girault, 1925

Plutarchia Girault, 1925: 3. Type species: Plutarchia bicarinativentris Girault, 1925.

Key to South Korean species of Plutarchia Girault

1

Head (Fig. 1D) with OOL more than 1.5x OD. Antenna with F2-5 slightly
longer than wide and F6 almost square (Fig. 1B). Propodeum (Fig. 1E) areolate-
rugose to reticulate medially with shallow medial depression. Fore wing (Fig. 1G)
dark infuscate basal half; vein dark brown............. eee P. fuscipennata sp. nov.
Head (Fig. 3D) with OOL less than 1.5x OD. Antenna with F2—F5 distinct-
ly longer than wide and F6 slightly longer than wide. Propodeum (Fig. 3G)
areolate without medial depression. Fore wing (Fig. 3H) hyaline; vein pale
DEO Wa sect scutterse ve. ieee cmaeeheeue cee P. malabarica Narendran & Padmasenan
Head (Fig. 2C) with POL less than 3.5x as long as OD. Antenna (Fig. 2B)
stout having funicle with short petiole; clava at most 3.0x as long as wide. Pro-
podeum (Fig. 2D) simply carinate to areolate-rugose with interspace some-
what reticulate. Petiole (Fig. 2D) almost smooth with inconspicuous sculp-
ture; 3.2—-3.4x as long as wide. Fore wing dark infuscate basal half; vein dark
ICON sce de OR tN oe i P. fuscipennata sp. nov.
Head (Fig. 4C) with POL more than 3.5x as long as OD. Antenna (Fig. 4B)
slender having funicle with distinctly long petiole; clava at least 4.0x as long as
wide. Propodeum (Fig. 4D) mixed with areolate-rugose and carinate-punctate.
Petiole (Fig. 4D) reticulate-imbricate; 3.09-3.11x as long as wide. Fore wing
hyaline; vein pale brown ................ P. malabarica Narendran & Padmasenan

Plutarchia fuscipennata sp. nov.
https://zoobank.org/7F772ABA-90DA-44EB-AAB7-ED2C4E3 23832
Figs LA-H, 2A—D

Etymology. The species is named after the Latin fusci (dark) and pennata (wing), from

the basally infuscate wing of the new species.

Type material. Holotype SoutH Korea: 9, San 1-6, Sujeom-dong, Gumi-

si, Gyeongsangbuk-do, 36°07'40.6"N, 128°18'05.1"E, 23.vi.2015, Duk-Young
Park (deposited in SNU). Paratypes SourH Korea: 23, Irwolsan-gil, Galsan-ri,
Jaesan-myeon, Bonghwa-gun, Gyeongsangbuk-do, 36°49'21.7"N, 129°05'05.3"E,
14.vii.2015, Duk-Young Park (each 1¢ in SNU and NIBR).

232 Duk-Young Park & Seunghwan Lee / Journal of Hymenoptera Research 97: 229-239 (2024)

Figure |. Plutarchia fuscipennata, holotype female A habitus, lateral view B antenna, dorsal view C head,
frontal view D head, dorsal view E mesosoma, lateral view F mesosoma, dorsal view G propodeum, dorsal

view H forewing.

Diagnosis. Plutarchia fuscipennata is easily distinguished from others by dark in-
fuscate anterior half of the fore wing.
Description. Holotype female (habitus: Fig. 1A). Body length 2.49 mm, including

ovipositor sheath. Body black except as follows: radicle and scape brownish-yellow with

First discovery of Plutarchia in Palearctic region, with description of a new species 233

Figure 2. Plutarchia fuscipennata, paratype male A habitus, lateral view B antenna, lateral view C head,

dorsal view D propodeum and petiole, dorsal view.

dark spot on dorsoapical region, funicle and clava dark brown except tip of clava slightly
brightened; trochanter, basal and apical region of femora and tibiae, protarsus brownish-
yellow, meso- and metatarsus whitish-yellow; fore wing with dark infuscate on basal half;
vein and setae dark brown; ovipositor sheath dark with extreme apex reddish-brown.

Head (Fig. 1C—D) 1.3x as wide as high in frontal view, 1.7x as wide as long in
dorsal view. Vertex areolate-reticulate to occiput regularly areolate; frons similar with
vertex in sculpture, but lower face carinate gathered to lower margin; with lanceolate
white setae. OOL: POL: LOL: OD = 1.6: 3.1: 1.4: 1.0. Preorbital carina weakly pre-
sented. Scrobal depression smooth with distinct carina laterally; scrobe not reaching
to anterior ocellus. Malar space 0.47x as long as height of eye; malar sulcus deep and
oviform connected with malar depression. Gena with two deep puncture groove lines,
lower punctures larger than the ones above; lateral outline of gena almost straight in
frontal view; genal carina present.

Antenna (Fig. 1B) with scape minutely swollen anteromedially; 3.4x as long as
wide. Pedicel square. Anellus thin and smoothly connected with pedicel. Flagellum
with six funiculars; Fl 1.7x as long as wide; F2—F5 slightly longer than wide and F6
square; each funicular with single row of MPS; all setae subdecumbent. Clava with two
visible clavomeres; 1.8x as long as wide.

Mesosoma (Fig. 1E—G) 1.6x as long as wide and 1.4x as long as high; prono-
tum 2.2x and mesoscutum 2.0x as wide as long respectively; mesoscutellum 1.3x as
long as wide. Dorsal surface of mesosoma punctate with interspace reticulate, except
medial region of pronotum with smaller punctures and mesoscutellum with larger

234 Duk-Young Park & Seunghwan Lee / Journal of Hymenoptera Research 97: 229-239 (2024)

punctures. Notauli shallow. Anterior half of axilla fused with mesoscutellum, but
distinguished by deep axillar groove posteriorly. Prepectus smooth with deep groove
transversely. Tegula shallowly imbricate except smooth medially. Epicnemium well
developed and double-hump shaped; adscrobal region areolate with interspace fine
reticulate; femoral depression and mesepimeron variously carinate-areolate, but me-
dial region of mesepimeron smooth. Metepimeron areolate with bearing long and
lanceolate setae. Propodeum in approximately 95° angle to the plane of mesoscu-
tellum; with median depression forming a single large square delimited by double
carina, and two smaller squares attached at the bottom; fine reticulate submedially
to areolate-rugose laterally. Legs. Procoxa with distinct S-shaped carina on anterior
surface; with sparsely foveate-reticulate anteriorly to reticulate posteriorly. Mesocoxa
somewhat smooth. Metacoxa shallowly imbricate; comparatively narrow and long,
2.1x as long as width; with two rows of setae. Fore wing (Fig. 1H). 2.33x as long as
wide; cc: mv: pmy: stv = 3.1: 1.4: 1.2: 1.0; with basal half dark infuscate and vein
dark brown; with dense dark setation on membrane.

Metasoma. Petiole wider than long in dorsal view. Gaster slightly longer than
head+mesosoma; 1.6x as long as high. GT4 the longest; with inconspicuous sculpture
on ventral half area. Syntergum slightly upturned.

Male (habitus Fig. 2A). Body length 1.39-1.43 mm. Morphologically similar to
female except as following. Antenna (Fig. 2B) with scape dark to pedicel and flagellum
dark brown; five funiculars and two clavomeres; funicle with short petiole; clava at
most 3.0x as long as wide. Head (Fig. 2C) 1.68—1.70x as wide as long in dorsal view;
OOL: POL: LOL: OD = 1.5-1.6: 3.2-3.4: 1.4-1.5: 1.0. Propodeum (Fig. 2D) sim-
ply carinate to areolate-rugose with interspace somewhat reticulate. Petiole (Fig. 2D)
almost smooth with inconspicuous sculpture; 3.2—-3.4x as long as wide.

Distribution. South Korea.

Biology. Unknown.

Remarks. Only one female and two males were collected using sweeping nets. The
biology of this species has not been confirmed, but it would be similar to that of other
species associated with Agromyzidae that attack Fabaceae.

Plutarchia malabarica Narendran & Padmasenan, 1990
Figs 3A—-H, 4A—-H

Plutarchia malabarica Narendran & Padmasenan, 1990: 115. Holotype °. Type loca-
lity: India (Kerala). Type depository: ZSIC, examined.

Material examined. SourH Korea: 1916, Bunori Fortification, Hwado-myeon,
Ganghwa-gun, Incheon, 37°35'28.1"N, 126°27'43.3"E, 20.ii.2021, Duk-Young Park,
emerged from pupae of Agromyzidae sp. at 01.vi.2022 (19 in SNU and 1d in NIBR);
13, Ganghwa Island, San 185-3, Sagi-ri, Hwado-myeon, Ganghwa-gun, Incheon,
37°35'28.1"N, 126°27'43.3"E, 15.iii.2018, Jongwoo Kim (in SNU); 14, Dok moun-

First discovery of Plutarchia in Palearctic region, with description of a new species = 235

tain fortress, Jigot-dong, Osan-si, Gyeonggi-do, 37°11'10.0"N, 127°01'17.9"E,
13.ix.2021, Duk-Young Park, emerged at 24.iv.2022 (in SNU).

Redescription. Female (habitus: Fig. 3A). Body length 2.08 mm, including ovi-
positor sheath. Body black except as follows: tip of scape, anterior half of pedicel,
anellus and anterior half of clava dark brown; protibia, trochanters and trochantellus
brownish-yellow; basal and apical tip of meso- and metatibia, and protarsus brown;
meso- and metatarsus whitish-yellow; fore wing hyaline with vein pale brown; oviposi-
tor sheath dark with apex yellowish-brown.

Head (Fig. 3C, D) 1.3x as wide as high in frontal view, 1.6x as wide as long in
dorsal view. Vertex to occiput regularly areolate; frons areolate to lower face carinate
gathered to lower margin; with linear to oblong white setae. OOL: POL: LOL: OD
= 1.3: 3.4: 1.6: 1.0. Preorbital carina inconspicuous. Scrobal depression smooth with
inconspicuous carina laterally; scrobe not reaching to anterior ocellus. Malar space
0.44x as long as height of eye in lateral view; malar sulcus indistinct; malar depression
absent. Gena with two deep and narrow puncture groove lines; lateral outline of gena
distinctly convex in frontal view; genal carina present.

Antenna (Fig. 3B). Scape minutely swollen anteromedially; 3.3x as long as wide.
Pedicel 1.4x as long as wide. Anellus transverse. Six funiculars, but F6 almost com-
bined with clava; F1 1.6x as long as wide; F2—F5 distinctly but F6 slightly longer than
wide; each funicular with single row of MPS; all setae subdecumbent. Clava with two
vague clavomeres; twice as long as wide.

Mesosoma (Fig. 3E-G) 1.5x as long as wide and 1.2x as long as high; prono-
tum, and mesoscutum 2.8x and 2.0x as wide as long respectively; mesoscutellum 1.4x
as long as wide. Dorsal surface of mesosoma densely punctate except mesoscutellum
with slightly larger punctures than mesoscutum. Notauli distinct and narrow. Ante-
rior half of axilla fused with mesoscutellum, but distinguished by shallow and broad
axillar groove posteriorly. Prepectus smooth with deep groove on ventral submarginal
area. egula smooth medially to imbricate posteriorly. Epicnemium developed and one-
hump shaped; adscrobal region areolate with interspace shallowly rough; femoral de-
pression variously carinate-areolate and mesepimeron substrigulate. Metepimeron are-
olate-rugose with bearing long and linear erect white setae. Propodeum approximately
90° angle to the plane of mesoscutellum; with broad median area delimited by carina;
callus areolate anteriorly to reticulate-rugose posteriorly. Legs. Procoxa with ambiguous
S-shaped carina on anterior surface; with surface imbricate. Mesocoxa shallowly imbri-
cate. Metacoxa imbricate; comparatively broad, 1.6x as long as width; with three rows
of setae. Fore wing (Fig. 3H). 2.15x as long as wide; cc: mv: pmv: stv = 5.3: 1.3: 1.4:
1.0; with entirely hyaline and vein pale brown; with sparse dark setation on membrane.

Metasoma. Petiole wider than long in dorsal view. Gaster 1.5x as long as height;
1.1x as long as head+mesosoma. GT4 with entirely reticulate-imbricate except antero-
dorsally one-fourth area smooth. Syntergum not upturned.

Male (habitus Fig. 4A). Body length 1.57—1.76 mm. Morphologically similar
to female except as following: antenna (Fig. 4B) with five funiculars and two cla-
vomeres; funicle with distinctly long petiole; clava at least 4.0x as long as wide.

236 Duk-Young Park & Seunghwan Lee / Journal of Hymenoptera Research 97: 229-239 (2024)

0.2 mm

Figure 3. Plutarchia malabarica, female A habitus, lateral view B antenna, lateral view C head, frontal
view D head, dorsal view E mesosoma, lateral view F mesosoma, dorsal view G propodeum, dorsal view

H wing.

First discovery of Plutarchia in Palearctic region, with description of a new species 237

Figure 4. A-D Plutarchia malabarica, male A habitus, lateral view B antenna, lateral view C head,

dorsal view D propodeum and petiole, dorsal view E leaves and pods of Pueraria lobata F pupa of Agro-
myzidae in pod of Pu. lobata G larva of P malabarica in pupa of Agromyzidae H male habitus emerged
from pupa of Agromyzidae.

238 Duk-Young Park & Seunghwan Lee / Journal of Hymenoptera Research 97: 229-239 (2024)

Head (Fig. 4C) 1.77—1.80x as wide as length in dorsal view; OOL: POL: LOL:
OD = 1.2-1.3: 3.7—3.8: 1.5-1.7: 1.0. Propodeum (Fig. 4D) mixed with areolate-
rugose and carinate-punctate. Petiole (Fig. 4D) reticulate-imbricate; 3.09—3.11x as
long as wide.

Variation. The length of the redescribed specimen (2.08 mm) in this study is
slightly longer than that of the types (1.39-1.93 mm). Additionally, the POL/OOL
ratio (2.62) is shorter compared to that of the holotype (3.22).

Distribution. South Korea (new record), India (Kerala).

Biology. We observed this species emerging from the cocoons of an unknown
leaf-miner species (Diptera: Agromyzidae), which attacked the seeds of Pueraria
lobata (Fabaceae). Seeds were collected during winter and subsequently stored un-
der laboratory conditions. Owing to the controlled environment, adults of P ma-
labarica emerged earlier than expected from the pupae of Agromyzidae. However,
their emergence is associated with oviposition by Agromyzidae on the seeds of Pu.
lobata, which occurred from September to October, when Pu. lobata seed ripening
process. The host record for P malabarica is the first discovery of a host association
for this species.

Discussion

Up to recently, Plutarchia was known to be distributed throughout the tropical (Ori-
ental: Cambodia, India, Sri Lanka, Southern China; Australasian: Northern Australia;
Afrotropical: Nigeria) to subtropical (Oriental: Nepal) zones of the Old World. Al-
though this genus is mainly distributed in the Oriental region, its type species, P bicar-
inativentris, was first discovered in Australia by Girault (1925). Another species, P gi-
raulti, was further identified in the Afrotropical region by Subba Rao (1974). However,
the recent discovery of P fuscipennata sp. nov., and P malabarica in South Korea sug-
gests that this genus may occupy a broader range across the Old World, including the
temperate zone of the Palearctic region.

The biology of most Plutarchia species remains unknown; however, information
exists for a few species. For example, P bicarinativentris was reared from the pods of
Glycine clandestina J. C. Wendl. (Fabaceae) in Australia (Boucek 1988) and is associ-
ated with Ophiomyia sp. (Agromyzidae) on Tephrosia purpurea (L.) Pers. (Fabaceae)
in Cambodia (Lotfalizadeh et al. 2007). Additionally, P indefensa was associated with
Melanagromyza sp. (Agromyzidae), and P giraulti was reared from an unidentified
dipterous pupa on Vigna unguiculata (L.) Walp. (Fabaceae) (Subba Rao 1974). In
this study, P malabarica was reared from the pupae of Agromyzidae that attacked
the seeds of Pueraria lobata (Fabaceae). Given the circumstances, Plutarchia may be
a main parasitoid of Agromyzidae species associated with Fabaceae, as proposed by

Boucek (1988).

First discovery of Plutarchia in Palearctic region, with description of a new species = 239

Acknowledgements

We are grateful to reviewer, Dr. Hossein Lotfalizadeh, and subject editor, Dr. Petr Jansta,
who helped improve the quality of this paper. This work was supported by a grant from
the National Institute of Biological Resources (NIBR), funded by the Ministry of Envi-
ronment (MOE) of the Republic of Korea (NIBR202203201 and NIBR202231206),
by the Basic Science Research Program through the National Research Foundation of
Korea (NRF), funded by the Ministry of Education (NRF2020R111A2069484), and
by the Institute for Peace and Unification Studies (IPUS) at Seoul National University
under the project of “Laying the Groundwork for Unification”.

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