Saphonecrus kuriphilusi Melika & Avtzis, 2018

Melika, George, Memtsas, George I., Nicholls, James A. & Avtzis, Dimitrios N., 2018, New species of cynipid inquiline, Saphonecrus kuriphilusi (Hymenoptera: Cynipidae: Synergini), from Dryocosmus kuriphilus galls in Greece, Zootaxa 4441 (1), pp. 109-120 : 111-116

Saphonecrus kuriphilusi Melika & Avtzis , new species

Figs 1–8

Type material. HOLOTYPE female: GREECE, Avgi (municipality of Langadas , Thessaloniki), and 13 female paratypes with the same labels as the holotype. The female holotype and seven paratypes are deposited in PHMB, four paratypes in Forest Research Institute , Greece and two paratypes in USNM .

Other material examined. Five females with the same labels as the holotype.

Etymology. The species is named after the inducer of its host gall, Dryocosmus kuriphilus .

Diagnosis. Saphonecrus kuriphilus , new species morphologically most closely resembles S. gallaepomiformis and S. barbotini . It also somewhat resembles species in the S. connatus / S. symbioticus clade; however, in S. kuriphilusi the head, mesosoma and metasoma are typically brown, and if black than only partially so, while in S. connatus and S. symbioticus the head and mesosoma are always black, the metasoma is black or dark brown. Morphological characters for the differentiation of the newly described species from S. gallaepomiformis / S. barbotini and S. connatus / S. symbioticus are provided in Table (see also Figs 9–28 ).

Description. FEMALE. Head yellow, except dark brown to black triangular area between antennal toruli and central ocellus, ocellar triangle, occiput; antenna, mandibles yellow with darker tips; mouthparts, maxillary and labial palps yellow; legs including coxae yellow; wing veins yellow; tegula yellow; propleuron, mesopleuron, mesopleural triangle, metasoma laterally reddish brown; rest of mesoscutum black; nucha and metasoma reddish brown; ventral spine of hypopygium yellow.

Head coriaceous, lower face, frons, gena, vertex, occiput, postocciput, postgena with dense white setae. Head slightly broader than high, rounded in anterior view, with broadest part level with torulus; slightly broader than mesosoma, 1.8´as broad as long in dorsal view. Eye 2.5´as high as length of malar space, eyes slightly converging ventrally. Malar sulcus absent, delicate striae radiating from clypeus and reaching eye. Clypeus small, coriaceous, with indistinct radiating striae, ventrally straight, not emarginate; epistomal sulcus indistinct; anterior tentorial pit small, distinct; clypeo-pleurostomal line indistinct. Lower face with striae radiating from clypeus and reaching torulus, extending into space between eye and torulus. Frons, interocellar area and vertex alutaceous, without striae and punctures. Transfacial distance slightly shorter than height of eye; distance between eye and torulus slightly greater than diameter of torulus; diameter of torulus 2.8´as large as distance between toruli. POL 2.0´as long as OOL and 2.0´as long as LOL; OOL 1.6´as long as length of lateral ocellus. Occiput alutaceous. Gena alutaceous, with white setae, not broadened behind eye, invisible in anterior view behind eye. Antenna with 12 flagellomeres, pedicel 1.4´as long as broad; F1 1.2´as long as F2 and 1.4´as long as pedicel; F3 1.2´as long as F2, F4 slightly longer than F3; F5=F6=F7; subsequent flagellomeres gradually shorten but do not broaden until apex; F11 1.2´as long as F10; placoid sensillae from F4.

Mesosoma 1.3´as long as high in lateral view. Pronotum coriaceous, laterally with interrupted delicate rugae, area between rugae alutaceous; lateral pronotal carina absent. Propleuron alutaceous, with some transverse striae basally. Mesoscutum with short white setae, with interrupted short delicate transverse rugae; area between rugae alutaceous, distance between rugae longer than width of ruga. Notaulus incomplete, reaching to 1/2–3/4 of mesoscutum length, broader posteriorly, narrowing till pronotum, with smooth bottom. Anterior parallel and median mesoscutal lines absent, parapsidal lines indicated by smooth, glabrous sculpture, parascutal carina present, extending to anterior edge of tegula. Dorsoaxillar area alutaceous, with setae, lateroaxillar area smooth. Mesoscutellum slightly longer than broad, uniformly rugose, disk of mesoscutellum rounded, laterally not emarginate. Scutellar foveae transverse, broader than high, slightly impressed, with smooth bottom; separated by distinct coriaceous median carina. Mesopectus smooth, with parallel longitudinal striae, area between striae smooth. Metapleural sulcus reaching posterior margin of mesopectus in upper half of its height. Metascutellum shorter than ventral impressed area; metanotal trough smooth, without setae. Propodeum coriaceous, with uniform dense short white setae on lateral and central parts; lateral propodeal carina thin, straight, parallel. Nucha with longitudinal parallel rugae.

Forewing as long as body, with long, dense cilia on margin, wing surface covered with dense short setae, radial cell open, 2.9´as long as broad; R1 and Rs nearly reaching wing margin; areolet large, triangular, Rs+M distinct, not reaching basalis, its projection reaches basalis at half its height. Legs with white setae, posterior surface of hind coxae with denser setae, tarsal claws simple, without basal lobe.

Metasoma as long as head+mesosoma, 1.3´as long as high in lateral view. Petiole with longitudinal parallel rugae dorsally and laterally. Syntergite with row of sparse setae anterolaterally, smooth, glabrous; posterodorsally not incised, with delicate punctures dorsally; subsequent tergites and hypopygium with delicate micropunctures; prominent part of ventral spine of hypopygium as long as broad in ventral view. Body length 2.2–2.4 mm (n = 10).

MALE. Unknown.

Biology. This species was reared from galls of Dryocosmus kuriphilus , collected from Castanea sativa in late April.

Distribution. Currently known only from Greece (Avgi, municipality of Langadas, Thessaloniki).

Comments. The two-gene phylogenetic analysis places Saphonecrus kuriphilusi new species sister to the trans-Palaearctic Saphonecrus lineage comprising S. connatus and S. symbioticus , and near to but distinct from the Western Palaearctic lineage containing Saphonecrus gallaepomiformis and S. barbotini ( Fig 29). This is in contrast to the morphology of these species, which would suggest a closer relationship of S. kuriphilusi to the lineage containing S. gallaepomiformis and S. barbotini . This may imply that the morphological characters used to define these close species relationships may be poor, as is observed in other cynipid inquilines ( Ács et al. 2010; Kaartinen et al. 2010). Alternatively, given that support for the basal nodes within the clade containing these species is not strong, further DNA data should be obtained to help determine the closest relatives of this new species. Irrespective of the relationships among them, it is clear that together these five species are more closely allied to Synophrus Hartig than other Saphonecrus species, confirming the previously-demonstrated polyphyly of Saphonecrus ( Ács et al. 2010, Bozsó et al. 2014, Schwéger et al. 2015b).

The association S. kuriphilusi new species with Castanea galls represents a novel ecological interaction, and phylogenetic relationship of S. kuriphilusi new species with other Saphonecrus (and Synophrus ) species associated with Quercus may provide indication as to the possible local oak galls from which this new inquiline species has been recruited onto D. kuriphilus galls on Castanea . Each of the major lineages within Saphonecrus defined by Schwéger et al. (2015b) are associated with cynipid galls induced on only a single genus of host plants. The disagreement between results of phylogenetic analyses based on morphology and DNA data with regard to the closest relatives of this new species also has implications about the native host plant species of the new species, i.e., whether it has shifted from native galls on Quercus section Cerris (the host plant group for S. barbotini / S. gallaepomiformis ) or from native galls on Quercus section Quercus (the host plant group for S. connatus / S. symbioticus ). Further research is needed to clarify what species of oak cynipid host galls it normally attacks. The recruitment of an inquiline onto invading D. kuriphilus populations is potentially exciting for natural biocontrol of this pest species by native parasitoids. Rates of parasitism by Chalcidoidea species attacking an invasive oak cynipid species in the United Kingdom increased after inquilines first started using the invading species’ galls ( Schönrogge et al. 1995). If the same happens with D. kuriphilus galls, we might expect parasitism by native parasitoids to increase, with potential deterimental effects on the pest’s populations.

Figures

FIGURES 1–2. Saphonecrus kuriphilusi, new species, female: 1, female, general view (rc, radial cell), 2, metasoma, dorsal view.

FIGURES 3–8. Saphonecrus kuriphilusi, new species, female: 3–5, head: 3, frontal view, 4, dorsal view, 5, posterior view. 6, antenna. 7, mesosoma, dorsal view. 8, metascutellum and propodeum, posterodorsal view.

FIGURES 9–20. Female: 9–10, Saphonecrus barbotini, head: 9, frontal view, 10, dorsal view. 11–12, S. gallaepomiformis, head: 11, frontal view, 12, dorsal view. 13–14, S. connatus, head: 13, frontal view, 14, dorsal view. 15–16, S. symbioticus, head: 15, frontal view, 16, dorsal view. 17–20, mesosoma, lateral view: 17, S. barbotini, 18, S. gallaepomiformis, 19, S. connatus, 20, S. symbioticus.

FIGURES 21–28. 21–24, Mesosoma, dorsal view, female: 21, Saphonecrus barbotini, 22, S. gallaepomiformis, 23, S. connatus, 24, S. symbioticus. 25–28, metasoma, lateral view, female: 25, Saphonecrus barbotini, 26, S. gallaepomiformis, 27, S. connatus, 28, S. symbioticus.