Head. Terminal flagellomere strongly acuminate. Scapus small, shorter ventrally than dorsally in lateral aspect, not apicolaterally emarginate. Eyes moderately large, glabrous, not emarginate. Malar suture well-developed. Dorsal margin of hypoclypeal depression not strongly protruding and lamelliform. Clypeus sharply demarkated from face by deep groove. Anterior tentorial pits large. Frons not inpressed behind antennal sockets, with strong midlongitudinal groove. Head strongly contracted behind eyes.

Mesosoma. Mesoscutum shiny, moderately densely with punctures at the bases of setae. Notauli very weak anteriorly, not impressed on dorsal surface. Mesopleuron smooth and shiny, largely glabrous. Precoxal suture not impressed. Pleural suture finely crenulate. Median area of metanotum with complete midlongitudinal carina. Midlongitudinal propodeal carina complete. Lateral carinae of propodeum absent, propodeum and metapleuron separated by deep groove.

Wings. Wings evenly setose. Forewing vein 1-SR+M virtually straight. Veins 1-SR and C+SC+R forming angle of aproximately 70°. 2^nd submarginal cell trapezoidal. Fore wing vein 1r-m with 2 distinct bullae. Hind wing vein 1-M more than 6 × length or r-m. Hind wing vein 2-SC+R longitudinal.

Legs. Hind tibia robust, without disting longitudinal groove. Claws with small, acutely pointed basal lobes.

Metasoma. Metasoma short and robust, with 5 exposed, coarsely sculptured tergites. 1^st tergite with spiracle approximately at midlength, with complete though somewhat irregular dorso-lateral carina behind spiracle, with dorsal carinae fused to form a semicircular transverse carina that runs far closer to posterior margin of tergite than its base. 2^nd+3^rd tergites large, their combined medial length more than 3 × length of exposed (coarsely sculptured) parts of tergites 4 and 5. 2^nd tergite without midbasal or anterolateral areas, with weak sublateral, posteriorly converging grooves on anterior 0.5 2^nd suture curved, narrow, crenulate. 3^rd tergite without anterolateral areas. Tergites without transverse subposterior grooves. Ovipositor short, sheaths approximately 1.2 × length of hind basitarsus.

Cassidibracon Quicke (1987b) belongs to the Plesiobracon Cameron (1903) group of genera as defined by van Achterberg (1983). It was originally described from the Afrotropical region (Sierra Leone) on the basis of three females and a male collected in seasonal woodland (Quicke 1987b). The type species Cassidibracon castus Quicke has a distinct knob between the antennal sockets which is absent in the new species described here as well as in the three other the Indian species described by Narendran et al. (1994).

The type specimens of the three oriental species described by Narendran et al. (1994), viz. Cassidibracon indicus Narendran & Rema, Cassidibracon malabaricus Narendran and Cassidibracon sumodani Narendran & Madhavikutty are now deposited in the collection of the Termeszettudomanyi Muzeum Allattara, Budapest, Hungary (van Achterberg and Narendran 1997).

Holotype. Female, “19.vi.1911, Parasite on Epicephala chalybacma, Pusa [INDIA], C. S. Misra”, “72” (BMNH)

Paratypes. 2 females, same data as holotype.

In Narendran et al.’s (1994) key to species, the new species runs to Cassidibracon sumodani Narendran because of its complete propodeal carina, but differs in having more (24 as opposed to 21) flagellomeres and in the dark pattern on the metasoma. The new species differs from all other known species of the genus in having a large ‘H’-shaped black mark extending over tergites 2–4.

Length of body 2.9 mm, of forewing 2.6 mm and of antenna 2.8 mm.

Head. Antenna with 24 flagellomeres. Median flagellomeres approximately 1.4 × longer than wide. 1^st flagellomere 1.1 × longer than both the 2^nd and 3^rd segments separately. Face shiny with numerous punctures at bases of setae. Height of eye: width of head: width of face = 1.0: 2.5 : 1.05. Intertentorial distance 1.7 × tentorio-ocular distance. POL: transverse diameter of posterior ocellus: shortest distance between posterior ocellus and eye = 1: 1 : 3.

Mesosoma. Mesosoma approximately 1.5 × longer than high. Midlongitudinal propodeal carina running within a deep, foveolate groove. Propodeum largely shiny, anteriorly smooth becoming distinctly weakly longitudinally striate medially merging to punctate sculpture posteriorly.

Wings. Fore wing vein cu-a marginally postfurcal. Lengths of fore wing veins r:3-SR:SR1 = 1.0: 1.7: 5.0.

Legs. Length of hind femur: tibia: tarsus = 1.2: 1.0: 1.0. Hind tibia 4.5 × longer than maximally deep.

Metasoma. Metasomal tergites irregularly densely punctulate. 2^nd tergite 1.9 × wider than medially long. 3^rd tergite 2.5 × wider than medially long.

Coloration. Antenna orange-brown becoming black on apical third. Head cream-yellow with stemmaticum black. Mesosoma largely cream-yellow with dark marks on lateral lobes and anterior of middle lobe of mesoscutum. Metasoma cream-coloured with large ‘H’-shaped black mark extending over tergites 2-4.

The type series of Cassidibracon gracillariae sp. n. are labelled as having been reared from ‘E[picephala]. chalybacma’ (now Stomphastis chalybacma (Meyrick, 1908)) (Lepidoptera: Gracillariidae).  Specimens of Stomphastis chalybacma in BMNH share the highly distinctive cocoons and there is no doubt that the original host identification was correct.  The host is a widespread moth in south-east Asia which mines leaves of Caesalpinia and Samanea species (Fabaceae).  The gracillariid, which feeds solitarily as a leaf-miner, pupates in a flattened silken cocoon ornamented with a cluster of distinctive bubbles, excreted by the larva, along the whole length of the cocoon.  These bubbles presumably serve a defensive (or camouflage) function and resemble an egg mass, or possibly a parasitoid cocoon mass.  The ovipositing Cassidibracon presumably attacks either pre-pupal larva or pupal hosts.