Diolcogaster Ashmead, 1900

Key to the species of Diolcogaster Ashmead View in CoL from India

1a Scutellum shallowly or sparsely punctate or interstices smooth and shiny......................................... 2

1b Scutellum coarsely or densely punctate or rugose............................................................ 4

2a POL: OOL = 1; T1 rugulose with median longitudinal groove extending from base to apex; T2 with grooves/sulci converging towards the middle at apex....................................................... D. dipika ( Bhatnagar, 1950)

2b POL: OOL less than 1; other characters differing.............................................................3

3a Face transversely striated; POL: OOL = 0.86; T1 and lateral fields of T2 yellowish-brown, T2 with distinct dark brown median field, remaining metasoma mostly dark brown; 1CU1: 2CU1 subequal; hind coxa: T1 = 1.77; median length T2: T3 = 0.66................................................................ D. solitaria Gupta & Fernández-Triana, 2015

3b Face longitudinally striated; POL: OOL = 0.69; T1, T2 and remaining tergites completely yellowish-brown; T2 with strong median field; 1CU1: 2CU1 = 0.67; hind coxa: T1 = 1.97; median length T2: T3 = 0.72.... D. tomentosae ( Wilkinson, 1930)

4a T1, T2 and T3 not forming carapace...................................................................... 5

4b T1, T2 and T3 forming carapace........................................................................ 14

5a Length of inner spur of hind tibia more than half the hind basitarsus............................................. 6

5b Length of inner spur of hind tibia equal to or less than half the hind basitarsus..................................... 9

6a T2 with weak median field............................................................................. 7

6b T2 with well-defined median field.........................................................................8

7a POL: OOL = 1.1; T1 nearly parallel sided, 2.5 × as long as its maximum width...... D. punctata ( Rao & Chalikwar, 1976) View in CoL

7b POL: OOL = 1.28; T1 1.35 × as long as its maximum width................................... D. confusus sp. nov.

8a Ratio of POL: OOL less than 1.5........................................................................ 12

8b Ratio of POL: OOL equal to or more than 1.5.............................................................. 13

9a Apical portion of first abscissa of cubital, recurrent and first transverse cubital vein almost equal............................................................................................... D. plecopterae ( Wilkinson, 1929)

9b Apical portion of first abscissa of cubital equal to recurrent but shorter than first transverse cubital.................... 10

10a Second abscissa of radius absent................................................... D. indica ( Wilkinson, 1927)

10b Second abscissa of radius present........................................................................ 11

11a 1-R1 1.35 × its distance from apex of radial cell; second abscissa of radius 1.5 × second transverse cubitus................................................................................... D. orientalis ( Rao & Chalikwar, 1970)

11b 1-R1 equal to distance from apex of radial cell; second abscissa of radius 0.5 × first abscissa and 0.66 × second transverse cubitus............................................................... D. rugulosa ( Rao & Chalikwar, 1970)

12a Antennae full black; ratio of POL/OOL 1.16.. aurangabadensis Fernández-Triana, 2020 (= D. indicus ( Rao & Chalikwar, 1970))

12b Antennae bicoloured with median white segments; POL/OOL 0.72........................................................................................................... D. duocolour Gupta & Fernández-Triana, 2015

13a T 1 not parallel sided, narrower at apex; 1.5 × its maximum width; T 2 with well-defined median field wider basally and separated from lateral surfaces by broad rugose furrows; T 3 1.2 × T 2 in length... D. breviterebrus ( Rao & Chalikwar, 1970)

13b T 1 slightly wider at apex than base, 1.2 × as long as its apical width; T 2 with well-defined median field; T 3 subequal to T 2 in length.......................................................... D. malabarensis Narendran & Sheeba, 2003

14a Ratio of POL: OOL less than 2..........................................................................15

14b Ratio of POL: OOL equal to or more than 2............................................................... 16

15a POL: OOL = 1.00; hind inner tibial spur 0.6 × hind basitarsus................... D. narendrani Rema & Sheeba, 2004

15b POL: OOL = 1.44; hind inner tibial spur 0.8 × hind basitarsus.......... D. longistria Gupta & Fernández-Triana, 2015

16a Fore wing with apical patch with distinct borders; ratio of hind wing veins (1-M/ M+CU) 1.24; T 2 with median apical black patch confined to apical one third region; T 3 with prominent punctations.................................................................................................. D. andamanensis Gupta & Fernández-Triana, 2015

16b Fore wing with apical patch without distinct borders; ratio of hind wing veins (1-M/ M+CU) 1.62; T 2 with distinct median black patch covering majority of the area; T 3 with prominent converging longitudinal rugae and without any punctations.............................................................................. D. pseudandamanensis sp. nov.