Idris semiflaviventris Veenakumari, 2021

Kamalanathan, Veenakumari & Mohanraj, Prashanth, 2021, An Atypical, Brachypterous Species Of Idris Förster (Platygastroidea: Scelionidae) From India *, Acta Zoologica Academiae Scientiarum Hungaricae 67 (1), pp. 7-13 : 9-11

Idris semiflaviventris Veenakumari sp. n. *

( Figs 1–6 )

Material examined: Holotype, female ( ICAR / NBAIR / P2693 ), INDIA: Tamil Nadu: Kodaikanal, Shenbaganur , 10 ° 14’01’’N 77 ° 30’47’’E, 1865m, YPT, 02.IV.2014. Paratypes: 1 fe- male, ( ICAR / NBAIR / P2694 ), same data as holotype ; 2 males, ( ICAR / NBAIR / P2695 , P2696 ), same data as holotype .

Description: Female body length = 0.98 mm (m = 0.93(0.88–0.98) mm, n = 2). Male body length = 0.83 mm (m = 0.85 (0.83–0.86) mm, n = 2).

Colour ( Figs 1 & 3 ): Head, mesosoma and T1 dark brownish black; remainder of metasoma yellowish brown; antenna brownish black; coxa, femur and anterior 3/4th of tibia blackish brown and remainder of leg brownish black.

Head ( Figs 1, 2, 5 & 6 ): Vertex and dorsal mesonotum covered with dense short white setae; head 1.23× as wide as high and 1.3× as high as long; IOS very short, 0.3× width of head, 0.57× eye length; dorsal frons rugose, antennal scrobe distinct on either side of central keel; vertex rugose; gena densely striate; anterior and posterior margins of gena parallel and converging dorsally; POL> LOL in ratio of 20.2:15.4; posterior ocelli contiguous with orbits; distance between hyperoccipital carina and posterior margin of lateral ocellus <0.4× MOD; posterior margin of eye touching hyperoccipital carina, densely setose, subequal in length and width; interantennal process rugose, protruding; facial striae and malar striae distinct; A1 and clava subequal in length; A2 3.1× as long as A3; A3 subequal in length and width; clava 2× as long as wide.

Mesosoma ( Figs 1, 5 & 6 ): Mesoscutum and mesoscutellum 0.65× and 0.57× as long as wide respectively; both mesoscutum and mesoscutellum with same sculpture as that on vertex; notauli absent; lateral pronotal area dorsally rugose, remainder predominantly smooth with sparse weak transverse carinae posteriorly; subacropleural sulcus and mese- pimeral sulcus foveate, speculum with deep furrows; mesopleural pit and mesopleural ca- rina distinct; ventral mesopleuron smooth with a rugose patch medially; ventral margin of mesopleuron extending as a narrow structure; metapleuron dorsally with transverse cari- nae, remainder smooth except for foveate metapleural sulcus posteriorly; paracoxal sulcus indicated as a furrow; posterior margin of mesoscutellum ‘V’ shaped, extending over an- terior margin of T1 hiding metascutellum and medial propodeum; posterior mesoscutel- lar sulcus foveate; propodeum triangular with vertical carinae, visible dorsolaterally, with postero-lateral corners extending as a spine; fore wing sclerite narrow extending up to T1.

Metasoma ( Figs 1, 5 & 6 ): Metasoma 0.82× as long as wide; T1 distinctly visible dor- sally and strongly costate, with a triangular granular patch laterally; T2 with anterior onethird costate; the remainder of T2 and other tergites with granular sculpture; T2 longest and widest of all tergites; posterior margins of T1 and T2 subequal; T2 1.4× as long as T3; T2 0.25× as long as the width of its anterior margin; submarginal ridge well impressed.

Male ( Figs 3 & 4 ): Similar to female. Antenna moniliform with nine visible anten- nomeres unlike that generally found in males of Idris which have 12 antennomeres where the last two antennomeres are either fused or have a distinct constriction between them.

Etymology: The species epithet ‘semiflaviventris’ refers to the yellow color of T2 and remaining tergites in both sexes. The name is treated as an adjective.

Diagnosis: Idris semiflaviventris sp. n. is unique among all the species of Idris so far described because of the following combination of character states: both male and female are brachypterous; T2 longer than T3 (except I. adikeshavus species group); posterior margins of T1 and T2 subequal; IOS narrow, at most 0.3× head width; male antenna with nine visible antennomeres. This com- bination of character states is not present in any other described species of Idris .

However, this species resembles two Indian species, I. triangularis Mukerjee and I. coorgensis (Mani et Mukerjee) in having a posteriorly extended mes- oscutellum. The salient differences between I. semiflaviventris and the other two species are T2 longest and widest of all tergites, posterior margin of T1 and T2 subequal; IOS short, at most 0.3× head width in I. semiflaviventris sp. n. while in the other two species T3 longer and wider than T2, posterior margin of T1 narrower than posterior margin of T2, IOS at least 0.6× head width.

Idris triangularis is macropterous; central keel on frons extending up to anterior ocellus; mesoscutum and mesoscutellum finely reticulate and shiny; T2 entirely costate; whereas I. semiflaviventris sp. n. is brachypterous, central keel on frons extending half the length of frons; mesoscutum and mesoscutel- lum rugose; T2 anteriorly costate and posteriorly rugose.

Idris coorgensis was described based on a male specimen. This species is also macropterous; notaulus present; male antennomeres A11 and A12 with distinct constriction; mesoscutum and mesoscutellum finely reticulate; T2 entirely costate; whereas I. semiflaviventris sp. n. is brachypterous; notaulus absent; male antennae with 9 visible antennomeres; mesoscutum and mesos- cutellum rugose; T2 anteriorly costate and posteriorly rugose.

Figures

Figs 1–6. Idris semiflaviventris sp. n.: 1 = habitus, dorsal view (female), 2 = head (female), 3 = habitus, dorsal view (male), 4 = head (male), 5 = habitus lateral view (female), 6 = habitus dorsal view (female)