Taxonomy of the genus Epsilon from China, with a new species and an updated key to the Oriental species (Hymenoptera, Vespidae, Eumeninae)

Abstract A new species of potter wasps, Epsilon similimanasicumsp. nov. is described and illustrated from Zhejiang, China. The holotype specimen of Epsilon subfistulosum (Wickwar, 1908) was examined and based on the characters of the type specimen, it is transferred from the genus Epsilon de Saussure to the genus Pararrhynchium de Saussure, as Pararrhynchium subfistulosumcomb. nov. In addition, an updated key to the Oriental species of Epsilon is provided.


Introduction
The genus Epsilon de Saussure, 1855 includes 17 known species and one subspecies, among which 14 species and one subspecies are distributed in the Oriental region and three species in the Australian region. Giordani Soika (1994) comprehensively reviewed the genus with the conclusion that it contains nine species and one subspecies, and provided a good basis for further taxonomic study of the genus which lead to more publications (Gusenleitner 1996(Gusenleitner , 2011Girish Kumar et al. 2014;and Selis 2017). To date, two species, E. fujianense Lee, 1981 and E. dyscherum (de Saussure) have been recorded from China (Lee 1981;Li et al. 2019). Except for these two species, one additional species from Zhejiang, China is recognized to be new to science, and is described and illustrated in detail. Meanwhile, because the existing descriptions and figures of the original description of Odynerus subfistulosum Wickwar, 1908 andin Giordani Soika (1941) appear to be inconsistent with the diagnosis of the genus Epsilon, such as the dentiform superior carina of the propodeum, and the sub-square tergum I which is basally truncated, slightly wider than long, and its lateral margins parallel, we examined the holotype specimen (NHMUK,type no. 18.314) deposited in the Natural History Museum, London. The study of the holotype of O. subfistulosum revealed that all the characters match the characters of the genus Pararrhynchium de Saussure. Further related characters and label information of the type specimen are given in this paper. Therefore, we suggest Epsilon subfistulosum (Wickwar, 1908) should be removed from the genus Epsilon to the genus Pararrhynchium de Saussure. Based on references and specimens, a key to the Oriental species is updated.

Materials and methods
The specimens examined are deposited in Chongqing Normal University, Chongqing, China (CN; CQNU), the Natural History Museum, London, Great Britain (UK; NHM), American Museum of Natural History, New York, the United States (USA; AMNH), and Yunnan Agricultural University, Kunming, China (CN; YNAU). Descriptions were made under a stereomicroscope (Olympus SZ2-ILST). Measurements were taken as the maximal length of body parts under an image analyzer, all figures were taken with a stereomicroscope (KEYENCE-VHX-5000) attached to a computer in Chongqing Normal University, and the plates were arranged with Photoshop CS 6. Body length was measured from the anterior margin of head to the posterior margin of metasomal tergum II. Terminology follows Yamane (1990).
Type species. Odynerus dyscherus de Saussure, 1853, by subsequent designation of van der Vecht, 1967: 31. Diagnosis. Clypeus much wider than long, with sparse or dense punctures (Figs 2, 13); cephalic fovea of female with two contiguous, deep pits (Figs 3,12); tegula with broad lobe posteriorly, almost equal to parategula (Figs 9,17); metanotum (Figs 7,21) narrow and very protruding, with a vertical posterior face, flat or gently convex, and a horizontal dorsal face; propodeum (Figs 7, 21) short, without superior carina and with weak lateral carina; second submarginal cell with second recurrent vein nearly or completely interstitial with third submarginal cell (Figs 5,14); tergum I without transverse carina basally, very short, ca. 2× as wide as long, and slightly narrower than tergum II (Fig. 20); tergum II (Figs 6,20) usually with apical lamella (Giordani Soika 1994;Girish Kumar et al. 2014 1): body length 7.5 mm. Black, with the following parts yellow: two lateral spots at the base of clypeus (Fig. 2), a small spot at the lower margin of ocular sinus, an elongated band on temple, an anterior interrupted transverse band on pronotum (Fig. 4), two spots on both anterior and posterior lobes of tegula, parategula, and horizontal dorsal face of metanotum (Fig. 7), a small apical spot on fore femur, small spots at outer sides of all tibiae, all tarsi ventrally, and apical bands of both terga I and II (Fig. 6). Body with white setae.
Head. In frontal view, head 1.2× as wide as long; clypeus 1.4× as wide as long in front view, slightly emarginated at the middle of apex, with minute and sparse punctures, interspaces between punctures longer than diameters (Fig. 2); interantennal space convex, with a hump-like transverse carina connecting longitudinal carina at its middle ( Fig. 2); frons coarsely punctate and reticulate; ocelli normal, diameter more than the distance between anterior and posterior ocelli, distance between posterior ocelli 1.6× as long as that between anterior and posterior ocelli (Fig. 3); interocellar area with micro-punctures; occipital carina developed laterally and weak dorsally (Fig. 3); cephalic fovea well developed and with two pits, total width of two pits distinctly shorter than distance between posterior ocelli (Fig. 3); punctures of vertex sparse, interspaces between punctures longer than diameters.
Mesosoma. Mesosoma with punctures coarser than those on head; anterior vertical face of pronotum medially with fine and transverse striae and two connected elliptical pits at the lower part, and coarsely punctate on sides, pronotal carina complete, dorsal face with coarse and dense punctures, interspaces between punctures less than diameters (Fig. 4); mesoscutum with dense punctures, punctures just sparser than those of pronotum; mesepisternum with reticulate punctures; tegula with broad posterior lobe ( Fig. 9); scutellum coarsely punctate medially and denser anteriorly and posteriorly; metanotum without tubercles, with horizontal dorsal face and vertical posterior face, the latter weakly convex in lateral view; propodeum short, both dorsal and lateral faces with coarse and reticulate punctures, posterior face almost vertical, broadly and shallowly depressed, and with distinct transverse striae and a longitudinal median carina ( Fig. 7), lateral surface largely striate; second recurrent vein of fore wing separated from first recurrent one, and arched in the middle (Fig. 5).
Male. Unknown. Remarks. This species is similar to E. manasicum Girish Kumar & Carpenter, 2014, but it can be distinguished from the latter and other species of the genus by the following characters: total width of two pits on the vertex distinctly less than distance between posterior ocelli (Fig. 3), anterior vertical face of pronotum with fine and transverse striae and two connected elliptical pits medially (Fig. 4), second recurrent vein of second submarginal cell separated from first recurrent one and arched in the middle (second recurrent vein of fore wing almost connected with first recurrent vein and rather arched in E. manasicum) (Fig. 5), and posterior face of propodeum with distinct transverse striae (Fig. 7).
Distribution. China (Zhejiang). Etymology. The specific name similimanasicum is named after the similar species E. manasicum, combined with the Latin word similis (= similar). Diagnosis. Clypeus in female wholly black, in male almost yellow except for apical margin (Figs 13, 15); cephalic fovea well developed, with two pits; total width of two pits distinctly shorter than distance between posterior ocelli (Fig. 12); anterior vertical face of pronotum medially with two separated elliptical depressions and indistinct fine transverse striae, but laterally almost smooth (Fig. 16); tegula with broad posterior lobe equal to parategula (Fig. 17); metanotum indistinctly faintly bi-dentate, lower vertical surface of metanotum coriaceous (Fig. 21); second recurrent vein of second submarginal cell close to first recurrent one, and nearly straight (Fig. 14); posterior surface of propodeum with few fine transverse striae and a median longitudinal carina (Fig. 21); tergum II with small or medium punctures, distances between punctures greater than diameters, and with short apical lamella (Fig. 20).

Key to the Oriental species of Epsilon (modified from Giordani Soika 1994)
1 Tergum II with large and dense punctures, interspaces between punctures equal to or less than diameters .. Clypeus very deeply emarginated at the apex, forming two wide and blunt teeth (Giordani Soika 1994: fig. 63 Body with red spots and bands (Gusenleitner 2011: fig. 9); clypeus with coarser punctures (Gusenleitner 2011: fig. 10 Anterior face of pronotum with few sparse punctures on sides (Fig. 16); metanotum with two blunt teeth (Fig. 21)  Total width of cephalic fovea pits distinctly shorter than distance between posterior ocelli (Fig. 3); anterior surface of pronotum with two connected depressions and fine transverse striae medially (Fig. 4); second recurrent vein of second submarginal cell separated from first recurrent vein and arched at the middle (Fig. 5); posterior face of propodeum with distinct transverse striae and not smooth (Fig. 7)