Chakra Rajmohana and Veenakumari

Keloth, Rajmohana & Kamalanathan, Veenakumari, 2014, Chakra, a new genus of Scelioninae (Hymenoptera: Platygastridae) from India, along with description of a new species, Zootaxa 3821 (2), pp. 285-290: 286

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Chakra Rajmohana and Veenakumari


Chakra Rajmohana and Veenakumari  , gen. nov.

( Figs 1–11View FIGURES 1 – 6View FIGURES 7 – 11)

Type species: Chakra sarvatra Rajmohana and Veenakumari. 

Derivation of genus name. ‘ Chakra  ’ in Sanskrit means wheel, referring to the unique wheel-like setigerous flat-topped tubercles distributed all over the head and mesosoma. The gender is feminine.

Diagnosis. Although the specimens of the new genus key out to Opisthacantha Ashmead  at couplets 59 of Masner (1976) and 50 of Austin and Galloway (1984), they do not fit into the concept of the genus Opisthacantha Ashmead sensu Masner (1976)  . The new genus differs from Opisthacantha  in having frons, vertex, dorsal, lateral and ventral mesosomal surfaces with large, round, setigerous tubercles, whose diameter is almost equal to the diameter of the lateral ocelli ( Figs 2View FIGURES 1 – 6, 11View FIGURES 7 – 11) and also in having remarkably small eyes that are hardly as long as temples, small ocellar triangle, with lateral ocelli much closer to median ocellus than to orbits (OOL> POL) and raised interantennal prominence.

Description. Body minute, 1.0–– 1.2 mm long. Head and body brown to blackish brown; Frons, vertex, dorsal, lateral and ventral mesosoma with large round setigerous tubercles, the diameter of the tubercles almost equal to diameter of lateral ocelli. Head distinctly transverse dorsally, subellipsoidal, densely setose; Occipital carina present, crenulate, extending throughout and continuing on lower margin of postgena; Eyes small, shorter than temples; Interommatidial setae short, 1.7 times as long as the diameter of a single ommatidium, comparable both in size and density to setae on frons and vertex; Temple visible in dorsal view; Ocelli clustered in a small triangle on vertex; OOL>POL>LOL ( Fig. 2View FIGURES 1 – 6); Frons convex without frontal depression; Interantennal process well developed with a pronounced curve ( Fig. 3View FIGURES 1 – 6); Clypeus narrow, transverse, more than 3 × as long as wide; Mandibles short and wide (L: W = 39: 48), subtridentate, median tooth highly reduced relative to lateral teeth ( Fig. 6View FIGURES 1 – 6); Teeth acute; Facial striae short, 0.9 × length of malar sulcus; Malar sulcus wide near inner orbit of eye; Subocular suture present ( Fig. 3View FIGURES 1 – 6); Antenna with 12 antennomeres in both sexes, with 6 clavomeres in females ( Fig. 8View FIGURES 7 – 11) and filiform in males ( Fig. 7View FIGURES 7 – 11), male A 5 carinate. Mesosoma almost as long as wide in dorsal view, both mesosoma and mesoscutellum with similar sculpture as head; Skaphion and notaulus absent ( Fig. 4View FIGURES 1 – 6); Mesoscutellum 2 × as wide as long, anterior margin crenulate; Lateral axillar area wide; Metascutellum foveolate with a broadly based triangular, medially pointed spine; Scutoscutellar sulcus wide; Epomial carina present; Netrion almost smooth, closed near fore coxa; Acetabular area setose, sculpture partially effaced in mesopleural depression; Mesepimeral sulcus foveolate; Metapleuron smooth dorsally, ventrally sculptured similar to mesonotum; Lateral propodeal area setose, with similar sculpture to that of head and mesoscutum; Propodeum with posterior margin concave medially, Posterior propodeal projection pointed downwards, with sparse setae ( Fig. 4View FIGURES 1 – 6); Tibial spur formula 1: 2: 2. Fore wing extending beyond tip of metasoma in flexed position; Fore wing submarginal vein not reaching anterior margin and not curved posteriorly or broken before fore wing marginal vein; Fore wing marginal vein shorter than fore wing stigmal vein and fore wing postmarginal vein; Fore wing stigmal vein placed at a broad angle of 45 0 from fore wing margin ( Fig. 9View FIGURES 7 – 11); other fore wing veins absent; Marginal ciliae present; Hind wing with submarginal vein complete. Metasoma pedunculate or spoon shaped ( Fig. 1View FIGURES 1 – 6), widest at its apical two-third, nearly as wide as mesosoma, shorter than head and mesosoma combined; Metasomal tergites transverse, T 1 without horn; T 1 and T 2 costate, costae reaching posterior margin of tergite; T 3 longest and widest; 7 tergites and 8 mediosternites in both sexes; Laterotergites narrow; Submarginal ridge well impressed; T 6 visible as a thin strip with lower margin emarginated; T 7 represented by a short lobe, external and not exerted with ovipositor.