The genus SycophilaWalker, 1871 is comparatively large size group in the family Eurytomidae, comprising 149 valid species (Lotfalizadeh et al., 2024), though only three species have been recorded in Korea: Sycophila biguttata (Swederus, 1795), Sycophila flavicollis (Walker, 1834), Sycophila variegata (Curtis, 1831). Sycophila is distributed across all zoogeographic regions, with one species recorded in Japan and two species recorded in Russia, while nine species have been recorded in China (Noyes, 2021).
Sycophila is distinguished from other Korean genera of Eurytomidae having an enlarged marginal vein. The genus is divided into three subgenera: FicorytomaLotfalizadeh & Rasplus, 2024;SycophilaWalker, 1871; and Tineomyza Rodani, 1872 (Lotfalizadeh et al., 2024). They primarily consist of endoparasitoids of gall wasps and flies (Hymenoptera: Cynipidae; Diptera: Cecidomyiidae and Tephritidae). Additionally, a significant proportion of species are associated with Ficus species (Moraceae), while a few species are attacking Lepidopteran larvae and Hemipteran nymphs (Noyes, 2021;Lotfalizadeh et al., 2024).
In this study, we report Sycophila hunanensisXiao & Gao, 2021 in Korea for the first time.
Material and Methods
Sycophila biguttata and S. flavicollis were collected using sweeping nets, and S. hunanensis were collected using Malaise traps, S. variegata were reared from the galls of Dryocosmus kuriphilus (Cynipidae). All specimens were deposited at the Laboratory of Insect Biosystematics, Seoul National University except one female specimen of Sycophila hunanensis is deposited at the National Institution of Biological Resources. Most morphological terms follow Delvare et al. (2019), and distribution and host information are based on Noyes (2021). The abbreviations for the depositories of the specimens used in this study are as follows:
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BMNH The Natural History Museum, Department of Entomology, London, England;
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HDOU Hope Department, Oxford University, Oxford, England;
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HNHM Hungarian Natural History Museum, Zoological Department, Budapest, Hungary;
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IZCAS Institute of Zoology, Chinese Academy of Sciences, Beijing, China;
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LUZN Zoological Museum, Lund University, Sweden;
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NIBR National Institution of Biological Resources, South Korea;
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SNU Laboratory of Insect Biosystematics, Seoul National University, South Korea.
Specimens were examined with an Olympus SZ61 stereomicroscope (Evident, Tokyo, Japan) and photographed with a DMC 5400 digital camera attached to a Leica Z16 APO motorized macroscope (Leica, Wetzlar, Germany). Serial images were combined using Zerene Stacker (Zerene Systems LLC, Washington, USA) and digitally retouched using Adobe Photoshop CS6 (Adobe System Inc., California, USA).
Abbreviations used in this paper as follows: 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; smv, submarginal vein; cc, costal cell; mv, marginal vein; pmv, postmarginal vein; stv, stigmal vein; M.T., Malaise trap.
Systematic accounts
SycophilaWalker, 1871 혹좀벌속(신칭)
SycophilaWalker, 1871: 63. Type species: Sycophila decatomoides Walker.
IsanisaWalker, 1875: 15. Type species: Sycophila decatomoides Walker.
PseudisaWalker, 1875: 15. Type species: Pseudisa smicroides Walker.
DecatomideaAshmead, 1888: 42-43. Type species: Decatomidea xanthochroa Ashmead.
EudecatomaAshmead, 1888: 42-43. Type species: Decatoma batatoides Ashmead.
Key to the Korean species of Sycophila
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2. Body entirely black with yellow spot on lateral side of pronotum. (Fig. 1A) ···································· S. biguttata
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- Body entirely yellowish-brown. (Fig. 1C) ·· S. flavicollis
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3. Body mainly yellow with black marks on dorsal side of head to metasoma. (Fig. 1E) ······················· S. variegata
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- Head and mesosoma reddish-yellow laterally and dark brown dorsally, but metasoma entirely dark reddish-brown. (Fig. 2A) ·················································· S. hunanensis
Sycophila biguttata (Swederus, 1795) 두점혹좀벌 (Fig. 1A-B)
Pteromalus biguttatusSwederus, 1795: 216. Unknown type status. Type locality: Sweden.
Decatoma cooperiCurtis, 1831: 345. Unknown type status. Type locality: United Kingdom.
Decatoma obscuraCurtis, 1831: 345. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Cinips fasciataFonscolombe, 1832: 288. Lectotype, ♀. Type depository: HDOU. Type locality: France.
Decatoma immaculataWalker, 1832: 27. Unknown type status. Type locality: United Kingdom.
Decatoma semifasciataWalker, 1834: 156. Unknown type status. Type locality: France.
Eurytoma signataNees, 1834: 43. Lectotype, Type depository: HDOU. Type locality: Germany.
Decatoma incrassataThomson, 1876: 31. Lectotype, ♀. Type depository: LUZN. Type locality: Sweden.
Decatoma inaequalisThomson, 1876: 32. Lectotype, ♀. Type depository: LUZN. Type locality: Sweden.
Decatoma strigifronsThomson, 1876: 32. Lectotype, ♀. Type depository: LUZN. Type locality: Sweden.
Material examined. 3♀♀, Jigwon-ri, Imgye-myeon, Jeongseongun, GW, Korea. 37°31'27.5"N 128°53'18.2"E, 11.vii.2020, Duk-Young Park (SNU).
Distribution. Andorra, Austria, Belgium, Bosnia Hercegovina, Bulgaria, Croatia, Czech Republic, France, Germany, Greece, Hungary, Iran, Italy, Kazakhstan, Korea, Macedonia, Moldova, Montenegro, Netherlands, Poland, Romania, Russia, Serbia, Slovenia, Spain, Sweden, Tunisia, Turkey, Ukraine, United Kingdom.
Host. Cynipidae:Andricus aestivalis, A. aries, A. callidoma, A. caputmedusae, A. conglomeratus, A. coriarius, A. corruptrix, A. gallaetincticorne, A. grossulariae, A. hungaricus, A. inflator, A. kollari, A. lignicolus, A. lucidus, A. multiplicatus, A. panteli, A. quercuscalicis, A. quercusfolii, A. quercusramuli, A. quercustozae, A. seckendorffi, A. testaceipes, A. trotteri, A. vindobonensis, Aphelonyx cerricola, Aylax sp., Biorhiza pallida, Callirhytis glandium, Chilaspis israeli, C. nitida, Cynips divisa, C. longiventris, C. quercus, C. quercusfolii, Diastrophus rubi, Diplolepis fructuum, D. mayri, D. rosae, Dryocosmus kuriphilus, Neuroterus albipes, N. glandiformis, N. lanuginosus, N. numismalis, N. quercusbaccarum, N. tricolor, Phanacis sp., Plagiotrochus australis, Rhodites sp., Synophrus politus, Trigonaspis mendes; Megastigmidae: Megastigmus pistaciae.
Associated Plant. Fagaceae: Quercus sp..
Sycophila flavicollis (Walker, 1834) 노랑혹좀벌 (Fig. 1C-D)
Decatoma flavicollisWalker, 1834: 156. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Eurytoma xanthomelasBoheman, 1836: 226. Unknown type status. Type locality: Sweden.
Eurytoma neesiiFörster, 1841: 31. Unknown type status. Type locality: Germany.
Material examined. 2♀, Sanghwa-ri, Danchon-myeon, Uiseonggun, GB, Korea. 13.vii.2016, 36°23'25.0"N 128°42'50.4"E, Duk-Young Park (SNU).
Distribution. Andorra, Austria, Bulgaria, Croatia, Czech Republic, Finland, France, Germany, Greece, Hungary, Iran, Korea, Montenegro, Netherlands, Poland, Romania, Slovakia, Spain, Sweden, Turkey, United Kingdom.
Host. Cynipidae:Andricus aries, A, conglomeratus, A, quercusradicis, A, testaceipes, Aulacidea hieracii, A, subterminalis, Cynips longiventris, C, quercus, Diplolepis rosae, Plagiotrochus quercusilicis, Synophrus politus, Trigonaspis brunneicornis.
Associated Plant. Asteraceae:Hieracium pilosella. Fagaceae:Quercu coccifera, Q, cerris, Q, faginea, Q, ilex, Q, petraea, Q, pubescens, Q, pyrenaica, Q, robur, Q, suber.
Sycophila hunanensisXiao & Gao, 2021 얼룩혹좀벌(신칭) (Fig. 2A-H)
Sycophila hunanensisXiao & Gao, 2021: 129-131. Holotype, ♀. Type depository: IZCAS. Type locality: China (Hunan).
Diagnosis. Body length = 2.2-2.3 mm. Body (Fig. 2A) mainly dark brown except antenna, lower margin of head, outer margin of eye, pronotum anterolaterally, lateral side of mesopisternum, legs and lower margin of metasoma yellowish to yellowish-brown; venation of fore wing (Fig. 2H) brown without dark spot under mv; setation of body whitish; setation of wings brown. Head 1.3× as wide as high in frontal view (Fig. 2C), 1.8× as wide as long in dorsal view (Fig. 2D); OOL: POL: LOL: OD = 1.3-1.4: 3.6-3.7: 1.7-1.8: 1.0. Funicular segments (Fig. 2B) slightely longer than wide. Propodeum (Fig. 2G) with median depression. Fore wing (Fig. 2H) 2.4-2.5× as long as wide; with more than 20 setae on smv; mv: pmv: stv = 9.1-9.2: 1.8-1.9: 0.6-0.7: 1.0.
Material examined. 4♀♀, Ara valley, Ara-dong, Jeju-si, JJ, Korea. M.T. 21.vi.-24.vii.2008, 33°26'15"N 126°33'37"E, J.W. Lee. (3♀♀ in SNU and 1♀ in NIBR).
Distribution. Korea (new record), China
Host. Cynipidae:Plagiotrochus glaucus (Xiao et al., 2021).
Associated Plant. Unknown.
Sycophila variegata (Curtis, 1831) 참나무혹살이좀벌 (Fig. 1E-F)
Decatoma variegataCurtis, 1831: 345. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Decatoma minutaCurtis, 1831: 345. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Decatoma unicolorCurtis, 1831: 345. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Cinips rufaFonscolombe, 1832: 290. Neotype, ♀. Type depository: BMNH. Type locality: France.
Decatoma tenuicornisWalker, 1832: 29. Lectotype, ♀. Type depository: BMNH. Type locality: United Kingdom.
Sycophila gilvaAbdul-Rassoul, 1980: 283. Holotype, ♀. Type depository: HNHM. Type locality: Iraq.
Material examined. 4♀♀2♂♂, Yeungnam Univ., Daehak-ro 280, Gyeongsan-si, GB, Korea. 06.vi.2017, 35°49'38.6"N 128°45'30.7"E, Duk-Young Park/Emerged from galls of Dryocosmus kuriphilus (Cynipidae) on Castanea crenata (Fagaceae) on 10.vi.2017 (SNU).
Distribution. Andorra, Austria, Bulgaria, China, Croatia, France, Greece, Hungary, Iran, Iraq, Israel, Italy, Japan, Jordan, Korea, Netherlands, Romania, Slovakia, Spain, Sweden, Switzerland, Turkey, United Kingdom.
Host. Cynipidae.Andricus coriarius, A. corruptrix, A. fecundatrix, A. grossulariae, A. hispanicus, A. kollari, A. lignicolus, A. pseudoinflator, A. quercustozae, A. vindobonensis, Biorhiza pallida, Callirhytis rufescens, Chilaspis israeli, Cynips sp., Diplolepis sp., Dryocosmus kuriphilus, Neuroterus glandiformis, N. lanuginosus, N. saliens, Plagiotrochus australis, P. kiefferianus, P. panteli, Plagiotrochus quercusilicis, Synergus umbraculus, Trichagalma serrata, Trigonaspis brunneicornis.
Associated Plant. Anacardiaceae:Pistacia lentiscus. Fagaceae:Castanea sativa, Quercu coccifera, Q. brantii, Q. cerris, Q. faginea, Q. frainetto, Q. ilex, Q. infectoria, Q. ithaburensis, Q. lanuginosa, Q. lusitanica, Q. pedunculiflora, Q. petraea, Q. pubescens, Q. pyrenaica, Q. robur, Q. suber.
Discussion
The genus Sycophila is one of the highly diverse groups within the family Eurytomidae, ranking fourth in species richness. They are primarily parasitoids of gall wasps, and some species are associated with Ficus (Moraceae). While 25 new species of Sycophila have been described from the Afrotropical region by Lotfalizadeh et al. (2024) and nine species have been recorded from China (Noyes, 2021), only four species have been reported from Korea. Given the presence of numerous Cynipidae species and three native Ficus species (F. erecta, F. oxyphylla, F. thunbergii) in Korea, it is likely that additional unrecorded Sycophila species also distribute in the region.
All Sycophila species recorded in Korea so far have been associated with cynipid galls, which are responsible for significant damage to various plants, especially Quercus species. Notably, S. biguttata and S. variegata parasitize the chestnut gall wasp, Dryocosmus kuriphilus, a major pest of chestnut trees, and there has been ongoing research into using these parasitoids for biological control of the pest (Kos et al., 2021). These Sycophila species also target other cynipid species that attack Quercus, suggesting that they have further potential as biocontrol agents. However, more research is needed to fully understand the ecological roles of these parasitoids and to explore their potential for managing cynipid populations in Korea.