Periclistus qinghainensis, Pujade-Villar, Juli, Wang, Yiping, Guo, Rui & Chen, Xuexin, 2016

Pujade-Villar, Juli, Wang, Yiping, Guo, Rui & Chen, Xuexin, 2016, Revision on Palaearctic species of Periclistus Foerster with description of a new species and its host plant gall (Hymenoptera, Cynipidae), ZooKeys 596, pp. 65-75 : 68-71

Taxon classification Animalia Hymenoptera Cynipidae

Periclistus qinghainensis sp. n. Figs 1, 2

Diagnosis.

Periclistus qinghainensis sp. n. differs from all of the known Periclistus species in the absence of notauli. Periclistus qinghainensis sp. n. is morphologically similar to two Japanese species ( Periclistus natalis Taketani & Yasumatsu and Periclistus quinlani Taketani & Yasumatsu) and the Far East Russian species ( Periclistus capillatus ) in having a smooth and shiny mesoscutum (very weakly alutaceous in Periclistus capillatus ) with dispersed piliferous points and smooth mesopleuron, but it differs from all these species in having a partially closed radial cell (radial cell opened in Periclistus natalis and Periclistus quinlani while closed and shorter in Periclistus capillatus ), shorter F1 than F2 (F1 and F2 subequal in Periclistus natalis and Periclistus quinlani ) and the absence of notauli (present in the other three species). Periclistus qinghainensis sp. n. differs from the European species in having the radial cell partially closed (closed in Periclistus caninae (Hartig) and Periclistus brandtii Ratzeburg), a smooth and shiny mesoscutellum (uniformly and delicately coriaceous scutellum with a dense and short pilosity without piliferous points in the European species) and the length and width of the radial cell (more than 4.0 times as long as wide in Periclistus qinghainensis while around 3.0 times in Periclistus brandtii and Periclistus caninae ).

Description.

Length. Female. Body length 2.1 mm, and fore wing 2.8 mm.

Colour. Body black, except yellow tegulae and antennae, scapus and apical flagellomere darker; coxae dark brown, rest of the legs yellowish; forewing hyaline, with brown veins.

Head (Fig. 1a, b). Head coriaceous, with sparse setae, 2.0 times wider than long in dorsal view, 1.4 times wider than high in front view and slightly wider than mesosoma. Gena delicately coriaceous and not broadened behind eyes. Clypeus very small, impressed quadrangular and delicately coriaceous, ventrally slightly rounded; slightly higher than wide, with distinct small anterior tentorial pits, epistomal sulcus and clypeo-pleurostomal lines indistinct. Lower face with striae radiating from clypeus, not reaching eyes and antennal socket, median elevated area delicately coriaceous and striated. Malar space 0.3 times longer than eye height. Diameter of antennal torulus 2.0 times longer than inter-toruli distance and 1.1 times longer than eye-torulus distance. POL: OOL: LOL=1.7: 0.6: 1.3. Frons, vertex, and gena behind eyes and postgena with sparse setae. Frons largely smooth, with some very small and distinct punctures but without lateral frontal carina. Vertex and occiput uniformly punctured.

Antenna. Female (Fig. 2a). 12-segmented, slightly shorter than body; pedicel subglobose, only slightly longer than wide; F1 2.5 times as long as pedicel; F2 around 1.2 times as long as F1 and only slightly longer than F3; the antennal formula is: 9: 4: 10: 13: 11: 11: 10: 9: 9: 8: 7: 14. Male (Fig. 2b, c). antenna 14- segmented, F1 medially incised and apically swollen, 2.3 times as long as pedicel, 0.9 times as long as F2; F2 as long as F3; F4 slightly longer than F3; F6-F8 equal in length; F9-10 equal in length; the antennal formula is: 3.0: 2.0: 4.2: 4.9: 5.0: 5.5: 5.0: 4.5: 4.5: 4.5: 4.0: 4.0: 3.5: 4.0.

Mesosoma (Fig. 1c, d). Mesosoma slightly compressed dorso-ventrally and longer than high in lateral view, and with white setae. Pronotum dorsal an lateral surface uniformly and delicately coriaceous, lacking wrinkles and lateral pronotal carina but having rounded anterior corners in dorsal view. Mesoscutum smooth and shiny with some dispersed piliferous points, slightly broader than long. Notauli and median mesoscutal line absent; anterior parallel lines distinct, extending to 1/4 of entire mesoscutum length. Parapsidal lines present, shallow, extending to 1/4 of mesoscutum length. Mesoscutum rugose, more sculptured toward central scutellar disk and between scutellar foveae, metanotum slightly overhanging. Scutellar foveae transversely ovate, only slightly wider than high, well-delimited around, with smooth and shiny deep bottom but without setae, separated by distinct medial carina. Mesopleuron smooth and shiny, without striae, with dense setae ventrally, especially postero-ventrally; mesopleural triangle alutaceous, with sparse setae. Metapleural sulcus reaching the mesopleuron at 4/5 of its height; lateral propodeal carinae straight and parallel, with some setae; central propodeal area coriaceous, with setae; lateral propodeal area uniformly and delicately coriaceous, with relatively dense white setae.

Fore wing (Fig. 2 d–f). Forewing longer than body, wing margin with long cilia; radial cell 4.3 times as long as the wide, partially closed (R1 vein projected about 1/3-1/2 on radial cell margin), Rs and R1 veins slightly curved, areolet distinct; vein Rs+M distinct, nearly reaching basalis.

Metasoma. Female (Fig. 1d). metasoma nearly as long as head plus mesosoma, distinctly longer than height in lateral view; metasomal tergites 2+3, with patches of dense setae at laterals in its base, fifth and sixth metasomal tergites broadly punctuate dorso-posteriorly; prominent part of ventral spine of hypopygium very short. Male. second and third metasomal tergites not fused, separated by a suture.

Type material examined.

Holotype. ♀, China: Qinghai, Huzhu, Bei Mountain (102°32'E, 36°51'N), 2010-V-6, Guo Rui, reared in galls on Rosa sp. Paratypes. 6♀♀1 ♂, same labels as the holotype (1♀ paratype UB).

Distribution.

China (Qinghai).

Biology.

Reared from stem galls on Rosa sp. (Fig. 1g and h). The young gall is juicy, soft, covered with small raised tubercles, and multilocular with greenish-purple spots, 1.0-2.0 cm in diameter. Adults emerge in September.

Etymology.

The new species is named after the province where it was collected.