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Research Article
Description of a new species of Pseudomegischus van Achterberg from China (Hymenoptera, Stephanidae)
expand article infoChen Huayan, Hong Chun-dan§, Kees van Achterberg|, Zai-fu Xu
‡ Department of Entomology, The Ohio State University, Ohio, United States of America
§ Nansha Entry-Exit Inspection and Quarantine Bureau, Guangzhou, China
| Naturalis, Leiden, Netherlands
¶ South China Agricultural University, Guangzhou, China
Open Access

Abstract

A new species of the genus Pseudomegischus van Achterberg, Pseudomegischus yunnanensis sp. n., is described and illustrated from Yunnan Province, China. This is the second species of the genus reported from China. A modified section of the identification key to species of Pseudomegischus is added to include the new species.

Keywords

Stephanidae, Pseudomegischus, new species, Oriental Region, China

Introduction

The genus Pseudomegischus van Achterberg, 2002 is a small group of parasitic wasps in the family Stephanidae (Hymenoptera), with only five described species worldwide (Tan et al. 2015). The genus seems to have an Indo-Australian distribution (van Achterberg 2002; Hong et al. 2011; Tan et al. 2015). According to Tan et al. (2015), the potential hosts of the genus include Cerambycidae (Coleoptera) and/or Siricidae (Hymenoptera). Here we report the second species of the genus from the Oriental part of China. We modify the key published by Tan et al. (2015) to include the new species.

Material and methods

Descriptions of the species have been made under an Olympus SZ61, with lighting achieved through a 27W fluorescent lamp. Photographic images were produced by a digital microscope (VHX-2000c, KEYENCE, Osaka, Japan), and plates were finished with ACDSee 10.0 and Photoshop CS 8.0.1, mostly to adjust the size and background.

Morphological nomenclature follows van Achterberg (2002) and the identification key is modified from the key to species of the genus Pseudomegischus in Tan et al. (2015).

Type material is deposited in the Shanghai Entomological Museum, Shanghai, China (SEMC) (Curator: Dr. Hai-sheng Ying).

Taxonomy

Pseudomegischus van Achterberg, 2002

Pseudomegischus van Achterberg, 2002: 169; Aguiar 2004: 73‒74 (list of literature); Hong et al. 2011: 7; Tan et al. 2015: 104. Type species (by original designation): Stephanus sulcifrons Schletterer, 1889.

Pseudomegischus yunnanensis Chen & Xu, sp. n.

Figs 1‒4, 5‒11, 12‒15

Material examined

Holotype, ♀ (SEMC), CHINA: Yunnan, Xishuangbanna, Menglun, 1000 m, 3.VI.2009, No. 34001533.

Etymology

Named after the province of the type locality.

Diagnosis

Frons coarsely obliquely rugose near anterior coronal tooth, transversely rugose ventrally (Fig. 1); vertex transversely carinate antero-medially, becoming smooth posteriorly (Fig. 3); middle part of pronotum transversely rugose anteriorly, largely smooth and without distinct carina posteriorly (Fig. 4); scutellum smooth medially, foveolate laterally (Figs 4, 7); propodeum coarsely and densely foveolate, without distinct smooth interspaces (Fig. 7); first tergite largely transversely rugose (Fig. 13).

Figures 1–4.

Pseudomegischus yunnanensis sp. n., holotype, female. 1 Head frontal 2 head lateral 3 head dorsal 4 pronotum and mesonotum dorsal.

Figures 5–11.

Pseudomegischus yunnanensis sp. n., holotype, female. 5 Propleuron and mesopleuron lateral 6 mesopleuron, metapleuron and propodeum lateral 7 scutellum and propodeum dorsal 8 hind coxa dorsal 9 hind coxa lateral 10 hind femur and tibia lateral 11 hind tarsus lateral.

Figures 12–15.

Pseudomegischus yunnanensis sp. n., holotype, female. 12 Wings 13 first tergite dorsal 14 metasoma dorsal 15 apex of ovipositor sheaths.

In the key to species of the genus Pseudomegischus by Tan et al. (2015), the new species can be included by replacing couplet 3 as follows:

3 Vein 1-M of fore wing 4.8‒5.4 × as long as vein 1-SR; hind femur with distinct third medium-sized tooth behind large posterior tooth; length of ovipositor sheath about 2.1 × fore wing P. sulcifrons (Schletterer, 1889)
Vein 1-M of fore wing about 3 × as long as vein 1-SR (Fig. 12); hind femur without distinct third medium-sized tooth behind large posterior tooth (Fig. 10); length of ovipositor sheath 2.3‒2.5 × fore wing 4
4 Hind basitarsus orange-brown, distinctly contrasting with blackish hind tibia; temple without distinctly differentiated ivory streak; hind femur moderately widened medially in lateral view P. celebensis van Achterberg, 2002
Hind basitarsus largely blackish-brown, not distinctly contrasting with blackish hind tibia (Figs 10, 11); pale or yellow streak of temple well differentiated (Fig. 2); hind femur strongly widened medially in lateral view 5
5 Propodeum densely irregularly rugose; first tergite largely smooth except irregular rugae basally and some oblique and fine striae after middle of first tergite P. notiochinensis Tan & van Achterberg, 2015
Propodeum coarsely and densely foveolate, without distinct smooth interspaces (Fig. 7); first tergite largely transversely rugose (Fig. 13) P. yunnanensis sp. n.

Description

Holotype. Female. Body length 21.2 mm; fore wing length 9.6 mm.

Colour. Black, except: frons yellowish-brown; temple brown with yellow streak along eye, streak becoming widened near vertex; base of mandible yellow; palpi, vertex, scape, pedicle, tegula and base of femora dark brown; veins and pterostigma largely dark brown, but base of pterostigma ivory; wing membrane slightly brownish; ovipositor sheath blackish apically (Fig. 15).

Head. Antenna with 41 segments; frons coarsely obliquely rugose near anterior coronal tooth, transversely rugose ventrally (Fig. 1); three anterior coronal teeth large and acute, both posterior ones arcuate and lamelliform, with two small lobe-shaped carinae on each side in front of both posterior ocelli; vertex transversely carinate antero-medially, becoming smooth posteriorly (Fig. 3); temple non-angulate, smooth and shiny (Fig. 2).

Mesosoma. Neck short and robust, transversely rugose, neck at much lower level than middle part of pronotum (Fig. 4); middle part of pronotum transversely rugose anteriorly, largely smooth and without a distinct carina posteriorly; propleuron largely coriaceous with sparse small punctures, shiny and densely setose (Fig. 5); mesonotum sparsely and irregularly foveolate and area between foveae smooth; notauli and median groove distinct; scutellum smooth medially, foveolate laterally; axillae irregularly and rather densely foveolate; mesopleuron distinctly convex, convex part coarsely foveolate-rugose and covered with long whitish setae and dense short setae; metapleuron coarsely foveolate (Fig. 6); propodeum coarsely and densely foveolate, without distinct smooth interspaces (Fig. 7).

Wings. Fore wing (Fig. 12): vein 1-M 3.1 × as long as vein 1-SR and curved; vein r ends slightly behind level of apex of pterostigma; first subdiscal cell robust, 3.2 × as long as its maximum width, vein cu-a entirely pigmented.

Legs. Hind coxa robust, without tubercle dorsally, transversely and densely rugose (Figs 8, 9); hind femur widened, smooth and with long whitish setae, ventrally with two large acute teeth (the anterior one larger than posterior one) and four denticles in between (Fig. 10); hind tibia 1.2 × as long as hind femur, basal narrow part of hind tibia about 1.2 × as long as widened part, widened part ventrally distinctly obliquely carinate (Fig. 10); hind basitarsus subparallel-sided, length of hind basitarsus 4.8 × as long as wide medially and 3.8 × as long as second tarsal segment (Fig. 11).

Metasoma. First tergite 9.0 × as long as its maximum width, 1.6 × as long as second tergite, cylindrical, largely transversely rugose (Fig. 13); remainder of tergites smooth and shiny (Fig. 14); length of ovipositor sheath 2.5 × length of fore wing.

Male. Unknown.

Distribution

Oriental: China (Yunnan).

Biology

Collected in June. Host not known.

Acknowledgements

We are very grateful to Drs Hai-sheng Yin and Wei-nian Zhang (the Shanghai Entomological Museum, Shanghai, China), for the loan of specimen; to Prof. Dr. Xue-xin Chen (Zhejiang University, Hangzhou, China) for providing imaging systems. We are very indebted to subject editor Prof. Dr. Michael Sharkey for his useful suggestions to improve the manuscript. This study is partly supported by the National Basic Research Program of China (No. 2013CB127600).

References

  • van Achterberg C (2002) A revision of the Old World species of Megischus Brullé, Stephanus Jurine and Pseudomegischus gen. nov., with a key to the genera of the family Stephanidae (Hymenoptera: Stephanoidea). Zoologische Verhandelingen Leiden 339: 1–206.
  • Aguiar AP (2004) World catalog of the Stephanidae (Hymenoptera: Stephanoidea). Zootaxa 753: 1–120.
  • Hong CD, Achterberg C van, Xu ZF (2011) A revision of the Chinese Stephanidae (Hymenoptera, Stephanoidea). ZooKeys 110: 1–108. doi: 10.3897/zookeys.110.918
  • Tan JL, Fan XL, Achterberg C van, Li T (2015) A new species of Pseudomegischus van Achterberg from China, with a key to the species (Hymenoptera, Stephanidae). ZooKeys 537: 103–110. doi: 10.3897/zookeys.537.6592