Dryocosmus salicinai Schweger & Tang, 2016

Tang, Chang-Ti, Miko, Istvan, Nicholls, James A., Schweger, Szabina, Yang, Man-Miao, Stone, Graham N., Sinclair, Frazer, Bozso, Miklos, Melika, George & Penzes, Zsolt, 2016, New Dryocosmus Giraud species associated with Cyclobalanopsis and non- Quercus host plants from the Eastern Palaearctic (Hymenoptera, Cynipidae, Cynipini), Journal of Hymenoptera Research 53, pp. 77-162 : 142-146

Dryocosmus salicinai Schweger & Tang sp. n. Figures 149-158 , 159-161

Type material.

HOLOTYPE female: TAIWAN: Taichung City, 104.5 K, Central Cross Island Highway, Heping Dist., ex monolocular bud gall on Quercus salicina (TWTb16), 24°12'44.4"N, 121°18'20.2"E, 2437m, gall collected 19.III.2012 (TWT583), adult emerged 4.IV.2012, leg. Chang-Ti Tang. Three female and four male PARATYPES: 4 male paratypes with the same labels as the holotype: 3 female paratypes: TAIWAN: Taichung City, 104.5 K, Central Cross Island Highway, Heping Dist., ex unilocular bud gall on Quercus salicina (TWTb16), 24°12'44.4"N, 121°18'20.2"E, 2437m, gall collected 19.III.2012 (TWT583), adult emerged 5.IV.2012, leg. Chang-Ti Tang.

The holotype female, 1 female and 2 male paratypes are deposited in NMNS, 1 female and 1 male paratypes in PHMB, 1 female and 1 male paratypes in NCHU.

Etymology.

The species is named after the host plant, Quercus salicina .

Diagnosis.

Dryocosmus salicinai is the only Dryocosmus species in which the mesopleuron and speculum are matt, uniformly coriaceous, without striae. In all other Dryocosmus species the mesopleuron and/or speculum are glossy and smooth. Albeit the structure of the mesopleuron is somewhat similar to that of Plagiotrochus , based on the a presence of the truncate apical tuft on the ventral spine of hypopygium and the smooth and glossy mesososcutum we treat this species as Dryocosmus .

Description.

Sexual female: Head color: black or dark brown, except for lighter clypeus; mandibles, maxillary and labial palps yellowish; scape and pedicel yellowish or light brown, flagellomeres progressively darker till last one. Mesosoma and metasoma color: mesosoma dark brown to black, except for lighter tegula; metasoma dark brown; legs uniformly brown.

Head sculpture: coriaceous. Head shape anterior view: NOT CODED. Head width / head length: 2.20. Head width / head height: 1.25. Head width / maximum mesosoma width: <1. Gena sculpture: coriaceous. Gena reflectivity: matt. Gena length / eye width: 0.40. Gena shape: broadened posterior to eye, visible in frontal view. Malar striae count: present. Malar striae dorsal limit: torulus-eye line on lower face and lower eye margin on malar area. Malar area: alutaceous. Malar sulcus: absent. Eye height / malar distance: 2.85. Inner margins of eyes: NOT CODED. Median ocellus shape: NOT CODED. Lateral ocellus shape: NOT CODED. POL / OOL: 1.10. OOL / diameter of lateral ocellus: 2.0. OOL / LOL: 2.0. Diameter of lateral ocellus / diameter of median ocellus:>1. Transfacial distance / eye height: 1.25. Diameter of torulus / intertorular distance: 1.70. Intertorular distance / eye torulus distance: NOT CODED. Eye-torulus distance / diameter of torulus: 1.50. Lower face sculpture: alutaceous. Lower face pilosity color: white. Lower face pilosity density: rare. Clypeus convexity: flat. Clypeus sculpture: smooth. Clypeus ventral margin shape: straight. Clypeus reflectivity: glossy. Clypeus shape anterior view: rectangular. Clypeus pilosity: NOT CODED. Clypeus pilosity density: NOT CODED. Clypeus pilosity color: NOT CODED. Anterior tentorial pit: large, distinct. Epistomal sulcus: indistinct. Clypeo-pleurostomal line: indistinct. Frons sculpture: coriaceous. Frons pilosity density: rare. Frons reflectivity: matt. Frons pilosity color: white. Impression around central ocellus: present. Interocellar area sculpture: coriaceous. Interocellar area pilosity density: rare. Interocellar area reflectivity: matt. Interocellar area pilosity color: white. Vertex sculpture: coriaceous. Vertex pilosity density: rare. Vertex reflectivity: matt. Vertex pilosity color: white. Occiput sculpture: coriaceous. Occiput pilosity density: rare. Occiput reflectivity: matt. Occiput pilosity color: white. Postocciput sculpture: coriaceous. Postocciput reflectivity: matt. Postocciput pilosity: present. Postocciput pilosity density: rare. Postocciput pilosity color: white. Median impression of postocciput dorsal to occipital foramen: present. Posterior tentorial pit: distinct, ovate, deep. Impression abjacent ventrally to posterior tentorial pit: present. Postgena sculpture: alutaceous. Postgena reflectivity: glossy medially. Postgena pilosity color: white. Postgena pilosity density: rare. Postgena pilosity count: absent medially, present laterally. Postgenal bridge / height of occipital foramen: <1. Postgenal bridge / length of oral foramen: <1. Postgenal bridge sculpture: NOT CODED. Number of flagellomeres (female): 13. Antenna length / body length: <1. Pedicel length / pedicel width: 1.30. Pedicel length / length of broadened part of scape: NOT CODED. Combined length of scape and pedicel / first flagellomere length: NOT CODED. F1 length / F2 length: 1. F1 length / pedicel length: 1.75. F1 length / F3 length: NOT CODED. Flagellomeres relative length: F3>F4>F5>F6>F7>F8>F9>F10>F11>F12. F4-F7 relative length: NOT CODED. F3 length/F2 length: NOT CODED. F3 length / F4 length: NOT CODED. F8 length / F7 length: NOT CODED. F9 length /F8 length: NOT CODED. F10 length / F9 length: NOT CODED. F9-F11 relative length: NOT CODED. F10 length / F11 length: NOT CODED. F12 length / F11 length: NOT CODED. F13 length / F12 length: 1. Placoid sensilla present on: F2-F13.

Mesosoma length lateral view / mesosoma height lateral view: 1.2. Pronotum sculpture: alutaceous with some rugae laterally. Pronotal dorsal row of setae count: present. Transverse pronotal sulcus depth: deep. Transverse pronotal sulcus sculpture: NOT CODED. Mesoscutum sculpture: smooth. Mesoscutum reflectivity: glossy. Adnotaular setae: present anteriorly. Mesoscutum length / transscutal line: 1.1. Notaulus limits: well-impressed, posterior end adjacent to posterior margin of mesoscutum, anterior end adjacent to anterior margin of mesoscutum. Notaulus sculpture: NOT CODED. Notaulus posterior region width / anterior region width: NOT CODED. Mesoscutal suprahumeral sulcus anterior end vs notaulus anterior end: adjacent. Mesoscutal suprahumeral sulcus sculpture: NOT CODED. Median mesoscutal line: absent. Median mesoscutal line shape: NOT CODED. Parapsidal line: absent. Parapsidal line distinctness: NOT CODED. Anteroadmedian line: absent. Antero-admedian line length / mesoscutum median length: NOT CODED. Dorsomedian area of mesoscutellar-axillar complex (disc of mesoscutellum+axillar foveae): coriaceous, foveolate laterally and posteriorly. Dorsomedian area of mesoscutellar-axillar complex (disc of mesoscutellum+axillar foveae) shape: trapezoid. Dorsomedian area of mesoscutellar-axillar complex (disc of mesoscutellum+axillar foveae) pilosity color: white. Dorsomedian area of mesoscutellar-axillar complex (disc of mesoscutellum+axillar foveae) pilosity density: rare. Mesoscutellar axillar complex posterior margin vs metanotum: overhanging. Mesoscutellar-axillar complex length / mesoscutellar disc width:>1. Disc of mesoscutellum sculpture: NOT CODED. Disc of mesoscutellum maximum width: in posterior 1/3. Scutellar fovea sculpture: smooth without longitudinal rugae. Scutellar fovea shape: transversely ovate. Scutellar fovea reflectivity: NOT CODED. Foveal septum: narrow. Anterior pits on foveal septum: NOT CODED. Scutellar fovea maximum diameter / scutellar fovea minimum diameter: 1.7. Scutellar fovea minimum diameter / foveal septum width: NOT CODED. Postacetabular suclus count: NOT CODED. Mesopleuron sculpture: coriaceous, striae marking transepisternal line absent. Mesopleuron reflectivity: matt. Mesopleuron pilosity: few setae present along margin of lateral mesopleural face. Speculum sculpture: coriaceous. Speculum reflectivity: matt. Mesopleural triangle sculpture: coriaceous. Mesopleural triangle reflectivity: NOT CODED. Mesopleural triangle pilosity: present. Mesopleural triangle pilosity color: NOT CODED. Mesopleural trinagle pilosity density: rare. Dorsoaxillar area sculpture: alutaceous with few rugae. Dorsoaxillar area reflectivity: NOT CODED. Dorsoaxillar area pilosity color: NOT CODED. Dorsoaxillar area pilosity density: NOT CODED. Lateroaxillar area sculpture: alutaceous with few rugae. Lateroaxillar area reflectivity: NOT CODED. Lateroaxillar area pilosity density: NOT CODED. Lateroaxillar area pilosity color: NOT CODED. Subaxillular bar sculpture: smooth. Subaxillular bar reflectivity: glossy. Posterior height of subaxillular bar / height of metanotal trough:>1. Metapleural sulcus anterior end: reaches mesometapleural suture in upper ⅓ of its length. Metascutellum sculpture: coriaceous. Metanotal trough sculpture: smooth. Metanotal trough reflectivity: glossy. Metanotal trough pilosity: absent. Metanotal trough pilosity density: NOT CODED. Ventral impressed area of metanotum sculpture: smooth without striae. Metascutellum height / ventral impressed area of metanotum height: 1. Central propodeal area sculpture: coriaceous with few irregular rugae. Central propodeal area reflectivity: NOT CODED. Lateral propodeal carina shape: broad, high, lyre-shaped. Lateral propodeal area sculpture: smooth with transverse rugae. Lateral propodeal area pilosity: present. Lateral propodeal area pilosity color: NOT CODED. Lateral propodeal area pilosity density: NOT CODED. Nucha sculpture: with delicate longitudinal rugae dorsally and laterally. Radial cell length / radial cell width: 3.6. Rs+M vs basalis: reaches basalis in lower half of its height. Rs+M color: dark brown. Areolet: large, triangular, conspicuous. Marginal cilia: long. Rs distal end vs wing margin: adjacent to wing margin. R1 distal end vs wing margin: adjacent to wing margin. Basal lobe on metatarsal claw: absent. Basal lobe on tarsal claw shape: NOT CODED. Metasoma length / head+mesosoma length: <1.

Metasoma lateral height / metasoma lateral length: <1. 2nd metasomal tergite length dorsal view / length of metasoma dorsal view: 1/3. Second metasomal tergite pilosity: present mediolaterally. Second metasomal tergite sculpture: smooth. Second metasomal tergite reflectivity: NOT CODED. Second metasomal tergite pilosity density: rare. Metasomal tergites 3-6 sculpture: smooth, micropunctate. Metasomal tergites 3-6 reflectivity: glossy. Metasomal tergites 3-6 pilosity: absent. Prominent part of ventral spine of hypopygium length ventral view / Prominent part of ventral spine of hypopygium width ventral view: 1.40. Hypopygial setae apical end: extending beyond posterior end of ventral spine of hypopygium.

Body length: 2.30 mm (n=1).

Male: Color: Head, mesosoma and metasoma dark brown; antenna brown; legs yellowish brown. Eye size vs female eye size: eye larger in male. Anterior tentorial pit size: NOT CODED. Diameter of lateral ocellus vs diameter of female lateral ocellus: 1.40. Male diameter of torulus / intertorular distance: NOT CODED. Flagellomeres count: 13. Antenna length / body length:>1. F1 shape: F1 curved and broadened apically. F1 length / F2 length: 1.3. Flagellomeres relative length: F2>F3>F4>F5>F6>F9>F10>F11>F12. F13 length / F12 length: 1.2. Placoid sensilla present on: F2-F13. Body length: 2.1 mm (n=1).

Gall (Figs 160-161 ): The unilocular gall is pink and ovate. One or two galls are embedded in one bud, which is usually flat and short. The gall is 2.1-2.6 mm long and 1.3-1.6 mm wide (n=5). The presence of the gall interrupts the development of the shoot.

Biology.

Only the sexual generation is known. Mature galls were collected in March and adults emerged from the galls under laboratory conditions in early April. This species induces galls on Quercus salicina .

Distribution.

Taiwan: Heping District, Taichung City, and Renai Township, Nantou County. The distribution of Quercus salicina (Govaerts & Frodin, 1998) suggests the potential occurrence of this gallwasp species in Japan.

Figures

Figures 149 - 158. Dryocosmus salicinai sp. n. 149 - 152 head, female: 149 frontal view 150 dorsal view 151 lateral view 152 posterior view 153 - 156 head, male: 153 frontal view 154 dorsal view 155 posterior view 156 lateral view 157 - 158 antenna: 157 female 158 male.

Figures 159 - 161. Dryocosmus salicinai sp. n. 159 metasoma, female, lateral view 160 - 161 galls (photos by C. - T. Tang).