Atree Ranjith, van Achterberg & Priyadarsanan 2022, gen. nov.
Creators: name: Ranjith, A. P.
name: Achterberg, Cornelis Van
name: Priyadarsanan, Dharma Rajan
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Braconidae
Atree

description: Atree Ranjith, van Achterberg & Priyadarsanan gen. nov.
(Figures 1–4)
urn:lsid:zoobank.org:act: CBCA6329-7722-49A9-B269-BD007D0372CB
Type species. Atree rajathae Ranjith, van Achterberg & Priyadarsanan sp. nov.
Description. Female
Head. Head wider than long (Figs 1B–D). Eyes sparsely setose (Figs 1B–F, 2A). Transverse diameter of eye slightly longer than temple in lateral view. Malar suture shallow (Figs 1B, E–F). Face smooth, distinctly punctate, slightly diverging posteriorly, setose (Fig. 1B). Tentorial pit deep (Fig. 1B). Clypeus with distinct acute lobe medioventrally (Figs 1B, D). Clypeal suture indistinct (Fig. 1B). Mandible curved with two teeth, upper tooth slightly longer than lower tooth (Figs 1B, D, F). Basal transverse groove of mandible less impressed (Figs 1E–F, 2A). Maxillary palp with five segments, labial palp with four segments (Fig. 1F). Frons smooth with distinct midlongitudinal carina (absent in A. improcerus) (Figs 1C–D). Ocelli arranged in equilateral triangle (Fig. 1C). Vertex and occiput smooth (Fig. 1C). Temple rounded in dorsal view (Fig. 1C). Occipital carina complete (Fig. 1C), joining with hypostomal carina above mandibular base (Figs 1F, 2A). Antenna with 31–44 antennomeres (Fig. 4C). Scapus longer than wide (Figs 4C–D). Pedicel slightly longer than wide (Figs 4C–D). First flagellomere with glandular opening, longer than second (Figs 4C–D). Medial flagellomeres slightly transverse (Fig. 4C). Terminal flagellomere pointed apically (Fig. 4C).
Mesosoma. Mesosoma longer than high (Figs 1A, 2D). Pronotum with deep pronope, crenulated groove postero-medially and extending laterally to posterior margin; without subpronope (Fig. 2B). Propleuron with ‘V’ shaped wide groove medially (Fig. 2E). Mesoscutum rounded in lateral view (Figs 1A, 2D). Notauli deeply crenulated, joining in a deeply punctate area above scutellar sulcus (Fig. 2C). Middle lobe of mesoscutum punctate anteriorly, lateral lobes smooth, sparsely setose with distinct lateral carina (Fig. 2C). Scutellar sulcus wide, crenulated (Fig. 2C). Scutellum smooth, setose (Fig. 2C). Mesopleuron with precoxal sulcus deeply impressed, setose (Fig. 2D). Prepectal carina present (Fig. 2D). Metapleuron mostly rugose with smooth median area with distinct lobe posteriorly (Fig. 2D). Metanotum with crenulated groove antero-medially, posteriorly widely crenulated with a smooth area medio-posteriorly, blunt (Fig. 2F). Propodeum rugose without longitudinal or transverse carina (Fig. 2F). Propodeal spiracle rounded (Fig. 2F).
Wings. Fore wing (Fig. 3A): Fore wing hyaline (Fig. 3A). Vein 1-SR absent (Fig. 3A). Pterostigma wide (Fig. 3A). Vein r originating from apical 1/3 rd. Marginal cell long (Fig. 3A). Vein cu-a postfurcal (Fig. 3A). Second submarginal cell parallel sided anteriorly (Fig. 3A). Vein r-m as long as 2-SR. Veins 1A and 2A present. Second subdiscal cell closed (Fig. 3A). Vein m-cu antefurcal (Fig. 3A). Vein 3-M distinct. Hind wing (Fig. 3B): Hind wing with three hamuli. Marginal cell subparallel apically (Fig. 3B). Vein M+CU 2.0 × longer than 1-M. Vein 2-SC+R longitudinal (Fig. 3B). Vein cu-a slightly curved (Fig. 3B).
Legs. Hind coxa smooth, setose (Fig. 1A). Tarsal claw slender, enlarged without basal lobe (Fig. 4E).
Metasoma. First tergite sculptured, except smooth and depressed basal area, and without converging dorsal carinae basally (Fig. 3E). Remaining tergites smooth and polished, mostly glabrous (Figs 4A–B). Ovipositor sheath setose (Fig. 1A), 0.45–1.7 × longer than fore wing. Ovipositor with distinct notch subapically (Fig. 4F).
Etymology. We dedicate the genus to the Ashoka Trust for Research in Ecology and the Environment (ATREE), a global environmental think tank and leading research institution commemorating their 25 years of active contributions in the fields of biodiversity conservation and sustainable development.
Distribution. Indomalayan region (India and Taiwan).
Comparative diagnosis. The new genus, Atree share a more or less plesiomorphic character, presence of wide, crenulate groove on propleuron with other diospiline genera. But Atree gen. nov. can be differentiated from the rest of genera in having a combination of characters viz., presence of deep pronope, second submarginal cell of fore wing parallel sided anteriorly and tarsal claw without basal lobe. The parallel-sided second submarginal cell of fore wing can be useful to separate the new genus from the diospiline genera, Aspicolpus and Vadumasonium. Additionally, the absence of curved longitudinal carina of first metasomal tergite clearly separate the new genus from Vadumasonium. Based on this character the new genus comes close to the nearest genus, Diospilus, but the former can be separated by a combination of characters like, presence of deep pronope, medial sulcus of propleuron widened anteriorly and tarsal claw without basal lobe. The new genus is also similar to the Australian genus, Depelbus in having clypeus with distinct protrusion medio-ventrally. This character is likely a homoplastic character within the tribe Diospilini, and it can be used as an intergeneric character only in combination with other characters.
So far, antennal glands have been reported only in braconid subgenera Aphidiinae (Aphidius) and Ichneutinae (Paroligoneurus) (Quicke 2015). Till now, this character is completely unknown from Brachistinae (Donald Quicke, personal communication). For the first time a glandular opening in the first flagellomere (Figs 4C, D) is reported from the Brachistinae genus Atree gen. nov. Detailed examination of the two Taiwanese species described in the genus Baeacis (junior synonym of Diospilus) falls in line with the character boundaries of the newly described genus. So, we hereby transfer these species to Atree gen. nov. as, A. improcerus comb. nov. and A. validus comb. nov. However, A. improcerus comb. nov. does not have the medio-longitudinal carina at the frons. The new genus, Atree belongs to the diospiline genus group (Aspigonus group) having distinct, anteriorly widened medial groove on propleuron and deep pronope.
Included species.
Baeacis improcerus Chou & Hsu, 1998 from China (Taiwan) => Atree improcerus (Chou & Hsu, 1998) comb. nov.
Atree rajathae Ranjith, van Achterberg & Priyadarsanan sp. nov. (India).
Baeacis validus Chou & Hsu, 1998 from China (Taiwan) => Atree validus (Chou & Hsu, 1998) comb. nov.
Key to species of Atree gen. nov.
1. Ovipositor sheath 0.4–0.5 × as long as fore wing; frons without medio-longitudinal carina; antenna with ca. 31 antennomeres; length of eye 1.1 × as long as temple; ovipositor sheath completely blackish brown; pterostigma 2.5 × as long as wide; first metasomal tergite 1.3 × as long as wide posteriorly (Taiwan) .......................... Atree improcerus (Chou & Hsu)
- Ovipositor sheath 1.6–1.7 × as long as fore wing; frons with medio-longitudinal carina (Fig. 1D); antenna with 40–44 antennomeres; length of eye 1.4–1.8 × as long as temple; ovipositor sheath yellowish apically (Fig. 1A); pterostigma 3.0–4.0 × as long as wide; first metasomal tergite 1.6 × as long as wide posteriorly........................................... 2
2. Pterostigma 3.0 × as long as wide; middle lobe of mesoscutum reticulate apically; first flagellomere 1.1 × as long as second; hind wing vein cu-a slightly curved; OOL 6.0 × as long as POL; hind basitarsus 9.6 × as long as wide (Taiwan) ......................................................................................... Atree validus (Chou & Hsu)
- Pterostigma 4.0 × as long as wide; middle lobe of mesoscutum punctate apically (Fig. 2C); first flagellomere 1.3 × as long as second (Figs 4C–D); hind wing vein cu-a distinctly curved (Fig. 3B); OOL 3.4 × as long as POL; hind basitarsus 6.7 × as long as wide (India)..................................................................... Atree rajathae sp. nov.
description: Published as part of Ranjith, A. P., Achterberg, Cornelis Van & Priyadarsanan, Dharma Rajan, 2022, Atree, a remarkable new genus of the subfamily Brachistinae (Hymenoptera: Braconidae) and the first report of the tribe Diospilini from India, pp. 571-580 in Zootaxa 5105 (4) on pages 572-577, DOI: 10.11646/zootaxa.5105.4.6, http://zenodo.org/record/6333882