Two new species of the genus Ancistrocerus Wesmael (Hymenoptera, Vespidae, Eumeninae) from China, with a key to the Oriental species

Abstract Two new species, namely Ancistrocerus transpunctatus You and Li, sp. n. and Ancistrocerus deqinensis You and Li, sp. n. are described and illustrated from Yunnan, China. A key to the Oriental species of the genus Ancistrocerus is provided.


Introduction
The key characters of the genus Ancistrocerus characterized as follows: pronotal carina weak dorsally (in some species obliterated) but strongly developed laterally; width of metasomal tergum I much greater than length, basally with a transverse carina; tergum and shape of the tegula. But it can be distinguished from the related species and other members of the genus with the following characters: apical margin of metasomal tergum II with a transverse row of big punctures, forming a transverse furrow (Fig. 5), terga III-IV reticulate, densely with large punctures.

Ancistrocerus deqinensis
Description. Male: Body length 7.0-7.8 mm (Fig. 7), forewing length 7.5-8.0 mm. Black; the following parts are yellow: a lower frontal spot, clypeus, a spot between antennal socket and eye, almost mandible; the parts are bright ferruginous: labrum, antennae ventrally, a spot on tempora, an anterior band on pronotum, outside half of tegula (Fig. 14), apical bands on metasomal terga I-VI and sterna I-VI, a median spot on sternum VII (Fig. 10), and apex of femora to tarsi V in all legs. Head. Densely covered with long setae, setae distinctly longer than the distance between the posterior ocelli; vertex with dense and coarse punctures, interspaces between punctures ridge-like (Fig. 9); width of clypeus equal to or slightly longer than length, clypeus moderately emarginate, almost semicircular, apically with acute teeth, sparse punctures and long setae (Fig. 8); antennal scape with sparse and small punctures, dense and long setae; antennal article XIII folded backward, reaching nearly the base of article XI (Fig. 12).
Mesosoma. Densely covered with long setae, similar to those on head; pronotal carina weaker in dorsum, but acutely produced in lateral corner. Mesopleuron reticulate, with large and irregular punctures; pronotum and mesonotum with dense and coarse punctures, smaller than those on mesopleuron; tegula with sparse punctures and long setae (Fig. 14); scutellum flat, metanotum convex, punctures on scutellum and metanotum similar to those on pronotum and mesonotum; marginal and median carinae of propodeum well developed, convavity of propodeum with striae; femora with dense long setae and sparse small punctures.
Metasoma. Densely covered with long setae, as long as the distance between the posterior ocelli; width of tergum I slightly less than 2 times length, with somewhat dense large punctures (interspaces smaller than punctures), transverse carina well developed, with a wide and deep median notch; apical bands on metasomal sterna I-VI complete; width of tergum II: length = 2.4: 2.0, the bottom of basal sulcus with longitudinal keels; punctures on terga II-VI much smaller than those on tergum I; sternum II basally with transverse uniform sulcus, not truncate behind sulcus, in profile somewhat concave (Fig. 11), punctures on sterna II-VI much sparser than those on tergum II.

Distribution. China (Yunnan).
Remarks. The species is similar to A. parietum (Cameron, 1900) from Europe to northeast of China and North America, in the shape of the clypeus, punctures on the mesosoma, transverse carina of tergum I well developed and with a wide and deep median notch. However, it can be distinguished from similar species and other members of the genus with the following characters: body markings bright ferruginous, tegula with sparse punctures and long setae (Fig. 14), terga II-VI with dense long setae (Fig.  13), apical bands on metasomal sterna I-VI complete and sternum VII with a medial spot (Fig. 10).
Etymology. It is named after the type locality of the species, Deqin County in Yunnan Province of China. Setae on frons and vertex as long as or shorter than the distance between the posterior ocelli; metasomal terga II-VI with very sparser and shorter setae ..3 2

Key to the Oriental species of Ancistrocerus
In male clypeus shallowly emarginate, almost semicircular (Fig. 8)  Apical margin of metasomal tergum II with a transverse row of big punctures, forming a transverse furrow (Fig. 5)  In Metasomal terga III-IV with apical bands; female without a spot between antennal socket and eye (Kim and Yamane 2009) ..... A. nigricornis (Curtis) -Metasomal terga III-IV without apical bands; female with a yellow spot between antennal socket and eye (Yamane and Gusenleitner 1993