Inostemma indicum Mani, 1941

Kamalanathan, Veenakumari, Shylesha, A. N. & Mohanraj, Prashanth, 2018, Neotype designation and redescription of Inostemma indicum (Platygastroidea: Platygastridae) parasitizing ivy gourd gall midge, Zootaxa 4420 (3), pp. 439-444 : 440-444

Inostemma indicum Mani

( Figs 1–11 )

Female: Body length = 2.116 mm; (m=2.110 (2.028-2.148) mm, SD=0.03, n=15)

Colour: Entire body black; legs honey brown except for black coxa, hind femur and distal tarsomere; radicle honey brown; A1 honey brown except for yellow patches laterally and apically; remaining antennomeres black except A2, A5, A6 which have a brown tinge ( Figs 1, 2 ).

Head ( Figs 1, 2, 3, 5 , 9 ): FCI= 1.42; LCI= 1.32; IOS 0.144× eye length; compound eye large (L: W= 21.6:19.1) with sparse minute setae; POL>LOL>OOL in ratio of 17.3:8.4:2.7; posterior ocelli away from orbits, OOL 0.46× OD; frons, vertex, gena finely reticulate, sparsely setose; hyperoccipital carina absent, occiput finely reticulate, uniformly setose; length and width of antennomeres A1–A 10 in ratio of 26.0:5.5, 7.9:3.4, 6.5:3.3, 4.8:3.7, 2.4:2.7, 3.7:3.5, 4.1:5.2, 5.4:5.8, 5.0:5.8, 7.7:4.5, respectively; A1 lamellate apically; radicle 0.13× length of A1.

Mesosoma ( Figs 3 , 10, 11 ): Mesoscutum (L: W=34.7:40.6) finely reticulate; notauli complete, posteriorly converging; a short midlobe posteromedially extending onto mesoscutellum; antero-admedian lines indicated; parapsidal ridges present; lateral pronotal area finely reticulate, uniformly setose, with a smooth depression anteromedially; anterior rim of pronotum reticulate-striate; pronotal groove smooth; mesopleuron anteriorly weakly reticulate, remainder smooth, with weak striae dorsally and reticulations ventrally; transepisternal line wide and triangular; mesopleural depression smooth; metapleuron covered with dense setae; scutoscutellar sulcus with large foveae on posterior margin. When horn removed: scutellar disc (L: W:19.5:21.0) finely reticulate with foveae on anterolateral margin; posterior margin of scutellar disc with a inverted ‘U’ shaped carina; posterior and posterolateral margin of scutellar disc predominantly smooth; metascutellum distinct, striate with weak foveae in between; metanotal trough predominantly smooth; lateral propodeal area unevenly sculptured, sparsely setose. Fore wing (L: W= 101.7:45.4) with a long submarginalis, 0.38× length of wing, ending with an elongate knob; microtrichia on fore wing uniformly setose in distal half and absent in basal half; hind wing (L: W=89.8:21.8) with sparse microtrichia; fore wing marginal cilia and hind wing marginal cilia 0.05× and 0.21× width of their respective wings.

Metasoma ( Fig. 6 ): (L: W=98.9:37.7); T 1 in female with a long horn (L:W=73.5:10.5), 0.75× length of metasoma, extending up to anterior margin of mesoscutum; T1 medially striate, of which two medial striae extend on to base of horn; horn finely transversely reticulate; T1 densely setose laterally; T2 anteromedially rugose and sparsely setose, laterally striate, striae extending 0.45× length of tergite and a few sparse lateral striae almost reaching the posterior end of tergite, remainder smooth; T3–T5 anteriorly reticulate and posteriorly smooth and each tergite with two transverse rows of setae; T6 entirely reticulate, setose and subequal in length and width; length and width of tergites T1 (exclusive of horn) –T 6 in ratio of 12.5:19.9, 46.3:23.7, 9.0:35.9, 8.1:30.7, 6.9:23.1, 15.2:15.1, respectively.

Male ( Figs 7, 8 ): Body length = 1.885 mm; (m=1.899 (1.864–2.01) mm, SD=0.05, n=15)。

Male similar to female except for the absence of horn and antennal characters; length and width of antennomeres A1-A 10 in ratio of 24.0:5.0, 6.7:3.6, 6.7:3.7, 7.0:3.1, 4.5:3.3, 6.8:4.2, 6.2:4.2, 6.5:4.0, 6.4:3.8, 10.1:3.9, respectively. T1 anteromedially smooth followed by costae, densely setose laterally; T2 anteriorly with an oblique carina oriented towards middle, beneath which short longitudinal striae present; T2 entirely smooth except anteromedially.

Material examined: Neotype female, ( ICAR / NBAIR /P1935), INDIA: Karnataka: Chikkaballapur, 13°25'56''N 77°43'40''E, 920m, 12.IX.2017, Coll. A. N. Shylesha. 23 females, ( ICAR / NBAIR /P1936–P1958) and 19 males ( ICAR / NBAIR /P2495–P2513), with same data as neotype.

Host: These parasitoids emerged from stem galls on Coccinia grandis caused by Neolasioptera cephalandrae ( Figs 12–14 ).

Diagnosis: Inostemma indicum females share the presence of a long horn on T1 with two other species from India, I. berijamum , and I. coorgense . This species differs from I. berijamum in the following character states: In I. berijamum fore wing densely setose, horn on T1 curved and away from body reaching anterior ocellus, T6 at least 1.8× as long as wide. Whereas in I. indicum microtrichia of fore wing sparse in basal half and horn on T1 not curved, almost adjacent to mesoscutum and not reaching head, length and width of T6 subequal. This species also differs from I. coorgense (type material unknown, Vlug, 1995) where vertex is smooth, gena sparsely punctate, horn on T1 extending ahead of posterior ocelli, mesoscutum smooth and shiny whereas in I. indicum vertex and gena finely reticulate, horn on T1 not reaching head, mesoscutum finely reticulate.

Acknowledgment: The authors are thankful to the Director, NBAIR, Bengaluru for providing facilities for carrying out this work. We are grateful to Dr. D. Dey for examining the type collection at the National Pusa Collection and indicating that the holotype of I. indicum is not present there. We thank Dr. John S. Noyes, History Museum, London; Dr. E. J. Talamas, DPI, Florida Mr. Peter N. Buhl for taxonomic discussion. We also thank V. Shashikala for all help rendered. We thank Dr. K. J. David for identifying the gall midge. Literature support by “The Platygastroidea Planetary Biodiversity Inventory Project” is acknowledged.

Figures

FIGURES 1–6. Inostemma indicum, neotype female (ICAR/NBAIR/P1935) 1. Habitus (dorsal view), 2. Habitus (lateral view), 3. Head and mesoscutum, 4. Male antenna, 5. Female antenna, 6. Metasoma.

FIGURES 7–11. Inostemma indicum (ICAR/NBAIR/P2495) 7. Male habitus (dorsal view), 8. Mesoscutellum and T1 (male), 9. Frons (female, ICAR/NBAIR/P1935), 10. Head and pleuron (female), 11. Wings (female).

FIGURES 12–14. Stem galls of Coccinia grandis, 12. Dried galls; 13. Fresh gall; 14. Close up view of stem gall showing a) emergence hole of parasitoid b) emergence hole of gall midge with pupal case.