A taxonomic account of the genus Stenodynerus from China, with descriptions of five new species (Hymenoptera, Vespidae, Eumeninae)

Abstract In this paper, 20 species of the genus Stenodynerus are reviewed and identified from China, including five new species: Stenodynerus ninglangensis Ma & Li, sp. n., Stenodynerus reflexus Ma & Li, sp. n., Stenodynerus similibaronii Ma & Li, sp. n., Stenodynerus strigatus Ma & Li, sp. n., and Stenodynerus tenuilamellatus Ma & Li, sp. n., and five new records: Stenodynerus baronii Giordani Soika, Stenodynerus bluethgeni van der Vecht, Stenodynerus picticrus (Thomson), Stenodynerus pullus Gusenleitner and Stenodynerus nepalensis Giordani Soika. The five new species are described and illustrated in detail. Moreover, the diagnostic characters of all new records and known species from China are provided, with a key to the Chinese species of Stenodynerus.


Introduction
The genus Stenodynerus of potter wasps was established by de Saussure (1863). This genus includes 161 species with 26 subspecies worldwide, and is distributed in the Nearctic, Neotropic, Palearctic and Oriental regions. These known species were described or revised by Bohart (1943Bohart ( , 1944Bohart ( , 1948Bohart ( , 1949Bohart ( , 1966Bohart ( , 1980, Buck (2008), Gusenleitner somewhat more than width; parategula just reaching apex of tegula; tergum I generally without a basal transverse carina (Figs 5,10,26,33,50,59,71,78), but in some Nearctic species present; tergum II without an acarinarium; the terminal segment of male antenna bent backward like a hook, apex usually reaching the base or middle of the segment XI (Fig. 19). This genus is similar in some characters to Parancistrocerus Bequaert, which can be distinguished by the presence of an acarinarium on the metasomal tergum II in Parancistrocerus.
Mesosoma. Pronotum, mesoscutum and scutellum densely punctate and reticulate, punctures somewhat larger and sparser than those on the head; punctures on metanotum sparser than those on other parts of the mesosoma. Anterior surface of pronotum shining, almost vertical, with few minute punctures, median foveae contiguous and V-shaped, pronotal carina complete (Fig. 3); scutellum distinct convex; metanotum oblique; dorsal and lateral surfaces of propodeum reticulate-punctate, dorsal surface broad with a weak shelf, posterior surface concave with long and transverse rugae and a median longitudinal carina (Fig. 4).
Metasoma. In dorsal view, tergum I domed, densely punctate, width 1.31 ×length and 0.85 × width of tergum II; tergum II with smaller and sparser punctures than tergum I, apex with deeper and denser punctures than other parts of tergum II, and apical margin without a distinct lamella, (Fig. 5); sternum II sparsely punctate, with a long median longitudinal furrow basally, and its anterior surface sloping (Fig. 6).

Male. Unknown.
Remarks. This species is easily distinguished from all the other members of Stenodynerus by the following character combinations: a basal band on clypeus except median interruption yellow (Fig. 2), apex of ocular sinus ferruginous (Fig. 2), apical margin of tergum II without a distinct lamella (Fig. 5), sternum II with a long median longitudinal furrow basally, and its anterior surface sloping (Fig. 6). is different from S. pappi and other members of the genus in the following characters: clypeus basally ferruginous except median interruption (Fig. 8), a broad band on pronotum ( Fig. 9), and sternum II with a very short median longitudinal furrow basally, and its anterior surface almost vertical (Fig. 12).
Mesosoma. Masosoma densely punctate and reticulate; punctures generally larger than those on the head; punctures on pronotal dorsum and mesoscutum somewhat denser than those on other parts of the masosoma (Fig. 14). Anterior surface of pronotum almost vertical with few small punctures, median foveae contiguous and V-shaped, a few short transverse carinae above median foveae, pronotal carina interrupted medially (Fig. 18); scutellum distinctly convex; metanotum oblique; dorsal and lateral surfaces of propodeum reticulate-punctate, dorsal surface broad with a weak shelf, posterior surface concave with long and transverse rugae and a median longitudinal carina (Fig. 21).
Metasoma. In dorsal view, tergum I domed, densely punctate, width 1.35 × length and 0.84 × width of tergum II; tergum II with smaller and sparser punctures than tergum I, apex with deeper and denser punctures than other parts of tergum II, and apical margin without a distinct lamella (Fig. 45); sternum II sparsely punctate, with a long median longitudinal furrow basally, and its anterior surface sloping (Fig. 22). Male (Figs 15,17,19,20): body length 6.8 mm, forewing length 5.6 mm. Sculpture, punctuation, setae and coloration similar to those of female except the follows: entire clypeus, mandible except apical portion, ventral scape and inter-antennal spot yellow; clypeus strongly, convex medially, with sparse and small punctures, its width equal to length, apex deeply emarginated and U-shaped, apical width: emargination depth = 0.27: 0.12, total width: apical width = 0.8: 0.27 (Fig. 17); punctures on apex of tergum II deeper than those in female; width of tergum I 1.45 × length and 0.79 × width of tergum II; the terminal segment of antenna bent backward like a hook, apex reaching the base of segment XI (Fig. 19). Male genitalia as in Fig. 20, volsella with setae and slightly truncate apically, parallel spines elongate without setae, penis valve rounded apically.
Mesosoma. Masosoma densely punctate and reticulate, punctures generally larger than those on the head; punctures on pronotal dorsum denser than those on others parts of the masosoma (Fig. 23). Anterior surface of pronotum sloping, shinning, with few punctures and a pair of round separated median foveae, the interspace between these two median foveae much more than one diameter, pronotal carina complete (Fig. 25); scutellum distinctly convex; metanotum nearly vertical; dorsal and lateral surfaces of propodeum reticulate-punctate, dorsal surface narrow with a weak shelf, posterior surface concave with long and transverse rugae and a median longitudinal carina (Fig. 27).
Metasoma. In dorsal view, tergum I campanulate, coarsely punctate, width 1.58 × length and 0.81 × width of tergum II, anterior surface vertical, almost impunctate, and with a median longitudinal carina and two transverse striations (Fig. 26); tergum II with smaller and sparser punctures than tergum I, and with a broad reflex apical lamella, dense and deep punctures forming a wide transverse groove on the base of lamella (Fig. 29); sternum II sparsely punctate, without a median longitudinal furrow basally, and its anterior surface almost vertical (Fig. 28).
Male. Unknown. Remarks. This species is similar to S. pappi by a median longitudinal carina on propodeal concavity (Fig. 27), anterior vertical surface of tergum I with a longitudinal median carina in upper half (Fig. 26), and tergum II with a broad reflex apical lamella (Fig. 29). It is different from S. pappi and other members of the genus in the following characters: a transverse median spot and two obscure apical spots on clypeus basally yellow (Fig. 24), pronotal dorsum mostly ferruginous (Fig. 25), the interspace of pronotal median foveae much more than one fovea diameter (Fig. 25), anterior vertical surface of tergum I with two transverse striations (Fig. 26), and sternum II without a median longitudinal furrow basally, and its anterior surface almost vertical (Fig. 28).

Stenodynerus tenuilamellatus
Mesosoma. Masosoma densely punctate and reticulate, punctures generally larger than those on the head; punctures on pronotal dorsum denser than those on other parts of the masosoma (Fig. 30). Anterior surface of pronotum somewhat sloping, with a few punctures and a pair of round separated median foveae, the interspace between two median foveae almost equal to one fovea diameter, pronotal carina complete (Fig.  32); scutellum distinctly convex; metanotum nearly vertical; dorsal and lateral surfaces of propodeum reticulate-punctate; dorsal surface narrow with a moderate shelf; posterior surface concave with long and transverse rugae and a median longitudinal carina (Fig. 34).
Metasoma. In dorsal view, tergum I campanulate, coarsely punctate, width 1.59 × length and 0.81 × width of tergum II, anterior surface vertical, almost impunctate, and with a median longitudinal carina in upper half (Fig. 33); tergum II with smaller and sparser punctures than tergum I, and with a narrow reflex apical lamella, a row of deep and dense punctures forming a narrow transverse groove on the base of lamella (Fig.  36); sternum II sparsely punctate, without a median longitudinal furrow basally, and its anterior surface vertical (Fig. 35).
Male. Unknown. Remark. This species is similar to S. pappi by a median longitudinal carina on propodeal concavity (Fig. 34), and anterior vertical surface of tergum I with a longitudinal median carina in upper half (Fig. 33). It is different from S. pappi and other members of the genus in the following characters: clypeus with a minute spot basally (Fig. 31); propodeal shelf moderately (Fig. 34); apical lamella of metasomal tergum II distinctly narrower than that of S. pappi (Figs 36,82), and sternum II without a median longitudinal furrow basally, and its anterior surface vertical (Fig. 35).

Diagnosis.
Almost whole body covered with large and dense punctures, strongly sculptured (Fig. 63). Cephalic fovea small and shallow, width less than the distance between posterior ocelli; basal half of clypeus yellow, with sparse punctures (Fig. 64); anterior surface of pronotum sloping, with distinct and strong punctures, median foveae V-shaped (Fig. 65); propodeal shelf weak, posterior surface concave, with a median longitudinal carina in lower half (Fig. 66); metasomal tergum II without a distinct apical lamella, apex with deep punctures (Fig. 67); sternum II with a long median longitudinal furrow basally, and its anterior surface sloping (Fig. 68).

Material examined. No specimens examined.
Diagnosis. Clypeus yellow, with small punctures, its width somewhat more than length, apex deeply emarginated; prontoal carina interrupted medially; tergum II with a broad reflex lamella apically. In male, metasomal terga I-VII and sterna II-III with yellow apical bands (Gusenleitner 1981).

Material examined. No specimens examined.
Diagnosis. Larger species, body length generally more than 10 mm. Clypeus yellow; pronotal carina less developed; metasomal tergum II without a distinct apical lamella; sternum II with a short median longitudinal furrow basally (Giordani Soika 1979;Gusenleitner 1981 Diagnosis. Clypeus yellow except margin, with sparse and shallow punctures, its width much more than its length; metasomal tergum II without a distinct apical lamella; anterior surface of metasomal sternum II vertical. Metasomal terga I-V and sterna II-III with yellow apical bands (Gusenleitner 1981).

Material examined. No specimens examined.
Diagnosis. The species differs from S. p. pappi as follows: body with extensive orange-yellow spots; a broad band on pronotal dorsum and almost entire metanotum orange-yellow; punctures on anterior surface of pronotum sparser, apical band on tergum I broader and reflex apical lamella of metasomal tergum II narrower than the corresponding parts in S. p. pappi (Kim and Yamane 2004).

Stenodynerus taiwanus Kim & Yamane, 2004
Stenodynerus taiwanus Kim & Yamane, 2004: 235, 237, 241. Material examined. No specimens examined. Diagnosis. Anterior surface of pronotum distinctly punctate, with a pair of round contiguous median foveae, pronotal carina weak; propodeal shelf absent, posterior surface concave, with a median longitudinal carina lost in upper half; anterior surface of metasomal tergum I almost impunctate, dorsal surface with weak and sparse punctures, the interspaces between punctures more than one diameter. Whole body with sparse and long setae (Kim and Yamane, 2004).

Key to the Chinese species of the genus Stenodynerus
The characters are applicable to both sexes unless the sex is specified. Metasomal tergum II with a narrow reflex lamella apically, the transverse groove on the base of lamella narrower (Fig. 36) ....S. tenuilamellatus sp. n. 4 In female, clypeus black (Fig. 77); in profile, anterior surface of metasomal sternum II sloping (Fig. 79)  Body with yellow spots; pronotum with a pair of small spots dorsally (Fig.  80), metanotum with a yellow band anteriorly (Fig. 81), tergum I with a narrower apical band (Fig. 78)  Anterior surface of pronotum with distinct punctures, the interspace between median foveae less than one fovea diameter (Fig. 9); propodeal shelf developed (Fig. 11); anterior vertical surface of tergum I without a transverse striation (Fig. 10); sternum II with a very short median longitudinal furrow basally (Fig. 12)  Anterior surface of pronotum with few punctures, the interspace between median foveae more than one fovea diameter (Fig. 25); propodeal shelf weak (Fig.  27); anterior vertical surface of tergum I with two transverse striations (Fig. 26); sternum II without a median longitudinal furrow basally (Fig. 28)