Research Article
Print
Research Article
First discovery of Plutarchia (Hymenoptera, Eurytomidae) in Palearctic region, with description of a new species from South Korea
expand article infoDuk-Young Park‡, Seunghwan Lee‡
‡ Seoul National University, Seoul, Republic of Korea

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

Academic editor: Petr Janšta
© 2024 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.
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
ZooBank: urn:lsid:zoobank.org:pub:22D7AF5B-7B43-4136-A6CF-1EE84016E25C
Open Access

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.

This genus concept has undergone several morphological revisions, with new species added by Subba Rao (1974), Bouček (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 characteristics, such as the projection of the mesopleuron, a procoxa with a large depression, and the fusion of 1st and 2nd gastral tergites with large basal pits, they have maintained an independent generic name.

The host of Plutarchia is not well known, but Bouček (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 Resources. The 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 photographed 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 posterior 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.

Taxonomy

Plutarchia Girault, 1925

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

Key to South Korean species of Plutarchia Girault

1 Female 2
– Male 3
2 Head (Fig. 1D) with OOL more than 1.5× 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 P. fuscipennata sp. nov.
– Head (Fig. 3D) with OOL less than 1.5× OD. Antenna with F2–F5 distinctly longer than wide and F6 slightly longer than wide. Propodeum (Fig. 3G) areolate without medial depression. Fore wing (Fig. 3H) hyaline; vein pale brown P. malabarica Narendran & Padmasenan
3 Head (Fig. 2C) with POL less than 3.5× as long as OD. Antenna (Fig. 2B) stout having funicle with short petiole; clava at most 3.0× as long as wide. Propodeum (Fig. 2D) simply carinate to areolate-rugose with interspace somewhat reticulate. Petiole (Fig. 2D) almost smooth with inconspicuous sculpture; 3.2–3.4× as long as wide. Fore wing dark infuscate basal half; vein dark brown P. fuscipennata sp. nov.
– Head (Fig. 4C) with POL more than 3.5× as long as OD. Antenna (Fig. 4B) slender having funicle with distinctly long petiole; clava at least 4.0× as long as wide. Propodeum (Fig. 4D) mixed with areolate-rugose and carinate-punctate. Petiole (Fig. 4D) reticulate-imbricate; 3.09–3.11× 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-ED2C4E323832
Figs 1A–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: ♀, 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 South Korea: 2♂, 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).

Diagnosis

Plutarchia fuscipennata is easily distinguished from others by dark infuscate 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 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.

Figure 1. 

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.

Head (Fig. 1C–D) 1.3× as wide as high in frontal view, 1.7× 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 presented. Scrobal depression smooth with distinct carina laterally; scrobe not reaching to anterior ocellus. Malar space 0.47× 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; 3.4× as long as wide. Pedicel square. Anellus thin and smoothly connected with pedicel. Flagellum with six funiculars; F1 1.7× 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; 1.8× as long as wide.

Mesosoma (Fig. 1E–G) 1.6× as long as wide and 1.4× as long as high; pronotum 2.2× and mesoscutum 2.0× as wide as long respectively; mesoscutellum 1.3× as long as wide. Dorsal surface of mesosoma punctate with interspace reticulate, except medial region of pronotum with smaller punctures and mesoscutellum with larger 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 medial region of mesepimeron smooth. Metepimeron areolate with bearing long and lanceolate setae. Propodeum in approximately 95° angle to the plane of mesoscutellum; 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, 2.1× as long as width; with two rows of setae. Fore wing (Fig. 1H). 2.33× as long as wide; cc: mv: pmv: 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; 1.6× 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 3.0× as long as wide. Head (Fig. 2C) 1.68–1.70× 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) simply carinate to areolate-rugose with interspace somewhat reticulate. Petiole (Fig. 2D) almost smooth with inconspicuous sculpture; 3.2–3.4× as long as wide.

Figure 2. 

Plutarchia fuscipennata, paratype male A habitus, lateral view B antenna, lateral view C head, dorsal view D propodeum and petiole, dorsal view.

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 loca­lity: India (Kerala). Type depository: ZSIC, examined.

Material examined

South Korea: 1♀1♂, 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 (1♀ in SNU and 1♂ in NIBR); 1♂, 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); 1♂, Dok mountain 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 ovipositor 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; ovipositor sheath dark with apex yellowish-brown.

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.

Head (Fig. 3C, D) 1.3× as wide as high in frontal view, 1.6× 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 0.44× 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; 3.3× as long as wide. Pedicel 1.4× as long as wide. Anellus transverse. Six funiculars, but F6 almost combined with clava; F1 1.6× 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) 1.5× as long as wide and 1.2× as long as high; pronotum, and mesoscutum 2.8× and 2.0× as wide as long respectively; mesoscutellum 1.4× as long as wide. Dorsal surface of mesosoma densely punctate except mesoscutellum with slightly larger punctures than mesoscutum. Notauli distinct and narrow. Anterior half of axilla fused with mesoscutellum, but distinguished by shallow and broad axillar groove posteriorly. Prepectus smooth with deep groove on ventral submarginal area. Tegula smooth medially to imbricate posteriorly. Epicnemium developed and one-hump shaped; adscrobal region areolate with interspace shallowly rough; femoral depression variously carinate-areolate and mesepimeron substrigulate. Metepimeron areolate-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 imbricate. Metacoxa imbricate; comparatively broad, 1.6× as long as width; with three rows of setae. Fore wing (Fig. 3H). 2.15× 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 1.5× as long as height; 1.1× as long as head+mesosoma. GT4 with entirely reticulate-imbricate except anterodorsally 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 clavomeres; funicle with distinctly long petiole; clava at least 4.0× as long as wide. Head (Fig. 4C) 1.77–1.80× 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; 3.09–3.11× as long as wide.

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 Agromyzidae in pod of Pu. lobata G larva of P. malabarica in pupa of Agromyzidae H male habitus emerged from pupa of Agromyzidae.

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 under laboratory conditions. Owing to the controlled environment, adults of P. malabarica 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 (Oriental: Cambodia, India, Sri Lanka, Southern China; Australasian: Northern Australia; Afrotropical: Nigeria) to subtropical (Oriental: Nepal) zones of the Old World. Although this genus is mainly distributed in the Oriental region, its type species, P. bicarinativentris, was first discovered in Australia by Girault (1925). Another species, P. giraulti, 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 suggests 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 (Bouček 1988) and is associated 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 Bouček (1988).

Acknowledgements

We are grateful to reviewer, Dr. Hossein Lotfalizadeh, and subject editor, Dr. Petr Janšta, 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 Environment (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 (NRF2020R1I1A2069484), and by the Institute for Peace and Unification Studies (IPUS) at Seoul National University under the project of “Laying the Groundwork for Unification”.

References

  • Bouček Z (1988) Australasian Chalcidoidea (Hymenoptera). A biosystematic revision of genera of fourteen families, with a reclassification of species. CAB International, Wallingford, Oxon, U.K. , Cambrian News Ltd; Aberystwyth, Wales, 832 pp.
  • Delvare G, Escola AR, Stojanova AM, Benoit L, Lecomte J, Askew RR (2019) Exploring insect biodiversity: the parasitic Hymenoptera, chiefly Chalcidoidea, associated with seeds of asphodels (Xanthorrhoeaceae), with the description of nine new species belonging to Eurytomidae and Torymidae. Zootaxa 4597(1): 1–90. https://doi.org/10.11646/zootaxa.4597.1.1
  • Girault AA (1925) Indications (in new insects) of ruling power and law in nature: 3 pp private publication, Brisbane.
  • Lotfalizadeh H, Delvare G, Rasplus J-Y (2007) Phylogenetic analysis of Eurytominae (Chalcidoidea: Eurytomidae) based on morphological characters. Zoological Journal of the Linnean Society 151: 441–510. https://doi.org/10.1111/j.1096-3642.2007.00308.x
  • Narendran TC (1994) Torymidae and Eurytomidae of Indian subcontinent (Hymenoptera: Chalcidoidea). Zoological Monograph, Department of Zoology, University of Calicut, Kerala, India, 500 pp.
  • Narendran TC, Padmasenan R (1990) A study on the Indian species of Plutarchia Girault (Hymenoptera: Eurytomidae). Journal of the Bombay Natural History Society 87: 114–122.
  • Subba Rao BR (1974) Redescriptions of Plutarchia Girault and Axanthosoma Girualt with the description of a new species Plutarchia from Nigeria (Eurytomidae: Hymenoptera). Journal of Entomology (B) 42(2): 199–206. https://doi.org/10.1111/j.1365-3113.1974.tb00075.x
login to comment