Corresponding author: Zai-Fu Xu ( email@example.com )
Academic editor: Michael Ohl
© 2017 Shuang-Sshuang Li, Zai-Fu Xu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Li S-S, Xu Z-F (2017) First record of Imasega Krombein from China, with description of one new species (Hymenoptera, Chrysididae, Amiseginae). Journal of Hymenoptera Research 54: 71-77. https://doi.org/10.3897/jhr.54.11675
The genus Imasega Krombein, 1983 is recorded from China for the first time, and one new species, I. bicolor Li & Xu, sp. n. (China: Guangdong) is described and illustrated. An updated diagnosis of the genus and a key to species are provided.
Amiseginae, Imasega, new species, key, Oriental Region, China
The genus Imasega was erected in the subfamily Amiseginae by
At present, the type species I. rufithorax Krombein is only known from Sri Lanka and the genus is unknown in China. In the course of our survey on the Chinese Chrysididae fauna, one new species of the genus Imasega was discovered and described herein.
The specimens were examined and described under stereomicroscope Leica MZ125. Photographs were taken with a digital camera CoolSNAP attached to Zeiss stereomicroscope Stemi 2000-CS. Images were processed using Image-Pro Plus software.
Morphological terminology follows
The holotype and paratypes of the new species are deposited in the Hymenopteran Collection of South China Agricultural University, Guangzhou (SCAU). The specimen of Imasega rufithorax Krombein (identified by Krombein in 1984) which is deposited in the Bohart Museum of Entomology, University of California, Davis, USA, was examined for comparison in this study.
Male. Antenna elongate; F4–F8 3.7–5.0 × as long as wide. Scapal basin slightly concave, with weak transverse rugulae. Malar space with vertical sulcus. Eyes bulging and with setulae. Occipital carina absent. Prothorax yellowish brown. Pronotum with longitudinal median groove posteriorly and pit before lateral lobe. Mesoscutum with notauli and faint parapsides. Notauli complete or incomplete. Mesopleuron without omaulus or scrobal sulcus. Metanotum 0.8–1.2 × as long as mesoscutellum medially, with large triangular median enclosure. Propodeum with short dorsal surface, and abrupt posterior and lateral surfaces; posterolateral tooth short and blunt. Forewing with R1 two-thirds as long as stigma or longer; Rs extended by curved dark streak. Hind coxa without dorsobasal carina. Tarsal claw with large median tooth. Metasomal tergites and sternites punctate. Female. Unknown.
Oriental Region: China (new record), Sri Lanka (
|1||Prothorax yellowish brown, mesothorax (excluding upper mesopleuron), metathorax and propodeum black (Figs
||I. bicolor Li & Xu, sp. n.|
|–||Mesosoma yellowish brown, with brown to blackish brown marks on pronotum, mesoscutum and metanotum (Figs
||I. rufithorax Krombein|
Holotype ♂, CHINA: Guangdong, Fengkai, Heishiding Provincial Nature Reserve, 1.X.2003, leg. Ju-jian Chen, No. 20047672 (SCAU). Paratypes: 1♂, CHINA: Guangdong, Fengkai, Heishiding Provincial Nature Reserve, 1.X.2003, leg. Ju-jian Chen, No. 20047664 (SCAU); 1♂, CHINA: Guangdong, Fengkai, Heishiding Provincial Nature Reserve, 1.X.2003, leg. Ju-jian Chen, No. 20047642 (SCAU); 1♂, CHINA: Guangdong, Longmen, Nankunshan Provincial Nature Reserve, 2–3.V.2005, leg. Zai-fu Xu, No. 200509614 (SCAU).
Holotype. Male. Body length 3.6 mm. Forewing length 2.8 mm. MOL = 2.0 MOD; OOL = 0.8 MOD; POL = 1.7 MOD; MS = 1.7 MOD. Relative length of S:F1:F2:F3 = 1.5:1.6:1.2:1.1.
Head. Head with setulae. Head 1.4 × as wide as distance from clypeal apex to posterior ocelli. Head (except scapal basin) punctate; punctures interspaced by 0.2–1.0 PD. Scapal basin slightly concave, with faint transverse rugulae and smooth longitudinal median ridge. Eye strongly bulging and with dense, erect setulae. Clypeal apex thickened. Mandible with one tooth. MS less than half of eye height. Ocellar triangle obtuse isosceles. Flagellum with dense, oblique setulae; flagellar setulae about half as long as width of flagellar segment; F1 4.5 × as long as wide; F2 3.4 × as long as wide; F3 3.4 × as long as wide; F4 3.7 × as long as wide; F5 3.8 × as long as wide; F6 4.2 × as long as wide; F7 4.3 × as long as wide; F8 4.4 × as long as wide. Occipital carina absent.
Mesosoma. Mesosoma with setulae. Pronotum punctate; punctures interspaced by 0.3–0.6 PD; pronotum with longitudinal median groove on posterior third; pronotum 0.8 × as long as mesoscutum medially; Mesoscutum punctate; punctures interspaced by 0.3–0.6 PD. Notauli incomplete, present posteriorly. Parapsidal lines weakly impressed. Mesoscutellum punctate. Mesopleuron punctate, without scrobal sulcus or omaulus; punctures interspaced by 0.1–0.7 PD. Metanotum punctate, medially 0.8 × as long as mesoscutellum, with triangular median enclosure 0.8 × as long as basal width. Metapleuron mostly smooth. Propodeum with short and blunt posterolateral teeth; posterior and lateral surfaces weakly rugose. Hind coxa without dorsobasal carina. Tarsal claw with large median tooth.
Metasoma. Metasoma with setulae. Metasomal tergites and sternites finely and sparsely punctate; punctures interspaced by 3.0 to 10.0 PD.
Colouration. Body without metallic reflection. Head black. Antenna blackish brown, with scape and pedicel yellowish brown. Mandible yellowish brown, with tooth reddish brown. Clypeus yellowish brown. Pronotum and propleuron yellowish brown. Mesoscutum, mesoscutellum, metanotum and propodeum black. Mesopleuron black, with upper area brown. Metapleuron black. Legs with coxae and trochanters whitish yellow, femora, tibiae and tarsi yellowish brown. Wings hyaline, with stigma and veins brown.
Variations. Paratypes. Body length 3.4–4.1 mm. Head 1.4–1.7 × as wide as distance from clypeal apex to posterior ocelli. F4–F8 3.7–4.4 × as long as wide. Pronotum 0.7–1.0 × as long as mesoscutum medially. Metanotum 0.8–1.1 × as long as mesoscutellum medially.
The specific name “bicolor” refers to the colouration of the mesosoma.
Imasega bicolor sp. n., male, holotype. 3 Antenna 4 Head, frontal view 5 Head and mesosoma, dorsal view.
We are very grateful to Dr. Lynn S. Kimsey (the Bohart Museum of Entomology, University of California, Davis, USA) for her kind help in the study of the specimen of Imasega rufithorax Krombein. We are very indebted to subject editor Dr. Michael Ohl and reviewers Dr. Lynn S. Kimsey and Mr. Paolo Rosa for their useful suggestions to improve the manuscript. The project was supported by the National Basic Research Program of China (No. 2013CB127600) and the National Natural Science Foundation of China (No.30770265).