Istiochrysis Rosa & Xu, gen. nov.
Creators: name: Rosa, Paolo
name: Feng, Jun
name: Xu, Zai-Fu
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Chrysididae
Istiochrysis

description: Istiochrysis Rosa & Xu, gen. nov.
(Figs 1A–1 F, 2A–2D, 3A–3D, 4A–4F)
Type species: Istiochrysis ziliolii Rosa, Feng & Xu, sp. nov.
Diagnosis. Istiochrysis Rosa & Xu, gen. nov. is similar to the Nearctic and Neotropical genus Caenochrysis Kimsey & Bohart, 1981, and the Palaearctic and Oriental genera Chrysidea Bischoff, 1913 and Trichrysis Lichtenstein, 1876. However, this new genus can be separated from Caenochrysis, Chrysidea and Trichrysis by male genitalia with extended longitudinal crest on aedeagus (Figs 1A–1 C); apex of aedeagus enlarged and folded laterally (Figs 1A, 1 B) (not enlarged in the other genera and tapering in Caenochrysis); facial fovea between antennal socket and lower margin of eye hardly visible and shallowly depressed and finely punctate (Figs 2A, 2 B) (usually deeply depressed in Caenochrysis); pronotum without sublateral carina (Fig. 3A) (usually with sublateral carina in Trichrysis); fore wing discoidal cell with thin and completely sclerotised outer vein (faint in Chrysidea); apex of T3 without teeth (laterally dentate and medially undulate in Chrysidea, tridentate in Trichrysis); S2 with large, subrectangular, black spots extending to lateral margins (Fig. 3 B), somehow similar to those in the genus Praestochrysis Linsenmaier, 1968 (small, suboval, not extending to lateral margins in Caenochrysis; suboval and separated in Chrysidea (Fig. 3 D), subtriangular and medially fused or nearly so in Trichrysis (Fig. 3 C)) (Bohart & Kimsey 1982; Linsenmaier 1984; Rosa & Xu 2015; Rosa et al. 2016a) (Fig. 2 D).
Description. Male. Head broader than high. Scapal basin with shallow depression on each side between antennal socket and lower margin of eye; depression visible only under certain angle (Figs 2A, 2 B); bottom of depression filled with micro-punctures and densely setose. Scapal basin topped by TFC (Figs 2A, 4 B); scapal basin with white setae, especially along lateral sides (Fig. 2A). F1 l/w>3; MS=1 MOD. Genal carina developed from gena to mandible. Subgenal area well defined. Median ocellus not lidded. Vertex without posterior depression beneath posterior ocellus. Mandible unidentate. Pronotum nearly as long as mesoscutellum with deep lateral depression, without sublateral carina. Mesopleuron with large episternal sulcus and scrobal sulcus (Fig. 4 D); area between episternal sulcus and scrobal sulcus large and subtriangular. Metanotum with raised median area. Fore wing with thin but completely sclerotized outer veins of discoidal cell (Fig. 3A). T2 and T3 with shallow median longitudinal carinae (Fig. 4 E). Apex of T3 without teeth, but with shallow concavity, thus appearing bilobate (Fig. 4 F); pit row well developed with enlarged and partly fused pits (Fig. 4 F). Black spots on S2 elongate, fused along lateral margins (Fig. 3 B) and distinctly separated mesally. Male genitalia with gonostyle of gonocoxa elongate and slender, aedeagus with enlarge longitudinal crest, well visible in lateral view (Fig. 1 C).
Female. Unknown.
Biology. Unknown.
Distribution. China (Yunnan).
Etymology. From Greek noun istion (= sail), referring to the unique subsidiary structure longitudinally placed on aedeagus, looking like a sail in lateral view. The gender is feminine.
description: Published as part of Rosa, Paolo, Feng, Jun & Xu, Zai-Fu, 2016, Istiochrysis gen. nov., a new chrysidid genus from Oriental China (Hymenoptera, Chrysididae), pp. 591-597 in Zootaxa 4111 (5) on page 592, DOI: 10.11646/zootaxa.4111.5.5, http://zenodo.org/record/263662