Identification key to Palaearctic species of Ismarus Haliday, 1835

Females

The female of I. brevis sp. nov. is unknown.

1. Body mainly pale yellowish to yellow, except at least mesoscutum, scutellum black (Fig. 1B) …… …………………………………………………………………… Ismarus dorsiger (Haliday, 1831)

- Body mainly dark brown or black (Fig. 1A, C -G) …………………………………………………2

2. Posterior part of scutellum finely coriaceous or rugose (Fig. 4D–E) ………………………………3

- Posterior part of scutellum smooth, sculptureless (Figs 5D, 6C, 7D) ………………………………4

3. Antenna uniformly brown to dark brown (Fig. 1E); posterior part of scutellum coriaceous; mesopleuron coriaceous-rugulose; metasoma deeply scaly-reticulate ……………………………… …………………………………………………………………… Ismarus rugulosus Förster, 1850

- Antenna uniformly bright yellow except for apical segment brownish (Fig. 4A, D); posterior part of scutellum rugose (Fig. 4D–E); mesopleuron smooth (Fig. 4A); metasoma weakly rugulose (Fig. 4A, D) ………………………………………… Ismarus distinctus Kim, Notton & Ødegaard sp. nov.

4. Scutellum truncate posteriorly, with hind margin straight (Fig. 7D); hind tibia abruptly swollen (Fig. 7B) …………………………………………………… Ismarus tripotini Kim & Lee sp. nov.

- Scutellum rounded posteriorly (Figs 5D, 6C); hind tibia gradually swollen (Fig. 5B, 6A) …………5

5. Mesopleuron with a continuous zone of sculpture extending from its anteroventral corner up to meso-metapleural suture (Figs 1I, 6D) ……………………………………………………………6

- Mesopleuron without a continuous zone of sculpture (Figs 1H, 5B) ……………………………7

6. Antenna uniformly yellow (Fig. 1G); mesopleuron with deep longitudinal wrinkles (Fig. 1I); base of second tergite with long median furrow, extending to ¾ of segment …………………… ……………………………………………………………… Ismarus flavicornis (Thomson, 1858)

- Antenna not uniformly yellow (Fig. 6A); mesopleuron with deep punctures to short irregular wrinkles (Fig. 6D); base of second tergite with short median furrow, extending 0.4-0.5 × length of tergite (Fig. 6E) ……………………………………… Ismarus similis Kim, Notton & Lee sp. nov.

7. Notauli with 5-8 pits; posterior half of S6 yellow …… Ismarus multiporus Kolyada & Chemyreva

- Notauli with 1-2 pits; only margin of S6 yellow …………………………………………………8

8. Antenna uniformly bright yellowish or only A15 brown (Fig. 1A, F) ……………………………9

- Antenna not bright yellow, variable (Figs 1C -D, 5A) …………………………………………10 9. Antenna uniformly bright yellowish (Fig. 1F); anterior scutellar pit with median keel; radial cell as long as length of marginal vein (Fig. 1F); A7-A14 subquadrate ………………………… ……………………………………………………… Ismarus spinalis Kolyada & Chemyreva, 2016

- Antenna bright yellow, except A15 brown (Fig. 1A); anterior scutellar pit without median keel; radial cell 0.8 × length of marginal vein (Fig. 1A); A7-A14 elongate ……………………………… ……………………………………………………… Ismarus apicalis Kolyada & Chemyreva, 2016

10. POL much longer than OOL (Fig. 5C) …………………… Ismarus excavatus Kim & Lee sp. nov.

- POL slightly longer or as long as OOL ……………………………………………………………11

11. A4 as long as A1, slightly shorter than A3 (Fig. 1D) ……………… Ismarus grandis Alekseev, 1978

- A4 shorter than A1 and A3 (Fig. 1C) ……………………………… Ismarus halidayi Förster, 1850

Males

The males of I. similis sp. nov. and I. tripotini sp. nov. are unknown.

1. A3 and A4 with keels (Fig. 2H) …………………… Ismarus spinalis Kolyada & Chemyreva, 2016

- A3 without keel, keel on A4 extending at least to ¾ of segment (Figs 3A, 4B, 5E) ………………2

2. Posterior part of scutellum finely coriaceous or punctate-rugose …………………………………3

- Posterior part of scutellum smooth, sculptureless (Figs 3D, 6C) ……………………………………4

3. Posterior part of scutellum coriaceous; mesopleuron coriaceous-rugulose; metasoma deeply scaly-reticulate ………………………………………………… Ismarus rugulosus Förster, 1850

- Posterior part of scutellum punctate-rugose (Fig. 4D–E); mesopleuron smooth (Fig. 4A); metasoma weakly rugulose (Fig. 4D–E) …… Ismarus distinctus Kim, Notton & Ødegaard sp. nov.

4. Mandibles white; notauli absent ……………………………… Ismarus dorsiger (Haliday, 1831)

- Mandibles black; notauli present ………………………………………………………………… 5

5. Mesopleuron with a continuous zone of sculpture extending from its anteroventral corner up to meso-metapleural suture (Fig. 2C) ………………………… Ismarus flavicornis (Thomson, 1858)

- Mesopleuron without a continuous zone of sculpture (Figs 2A, D -F, 3B, 5F) ……………………6

6. Radial cell shorter than marginal vein (Fig. 2A) …… Ismarus apicalis Kolyada & Chemyreva, 2016

- Radial cell as long as marginal vein (Figs 2D -F, 3B, 5F) …………………………………………7

7. Notauli with 5-8 pits ………………………… Ismarus multiporus Kolyada & Chemyreva, 2016

- Notauli with 1-2 pits (Figs 3D) ……………………………………………………………………8

8. A3 shorter than A4 (Fig. 5F) ………………………………………………………………………9

- A3 as long as or slightly longer than A4 (Fig. 3A) …………………………………………………10

9. POL as long as OOL; antennal segments distinctly elongate, at least 2.0 × width of each segment (Fig. 2D); A4 as long as A1 (Fig. 2D); A4 slightly excavate (Fig. 2D); base of second tergite with long median furrow, at least to ¾ of segment …………… Ismarus grandis Alekseev, 1978

- POL longer than OOL; antennal segments not distinctly elongate, A5-A13 only slightly longer than wide (Fig. 2E); A4 shorter than A1 (Fig. 5F); A4 distinctly excavate (Fig. 5F); base of second tergite with short median furrow, extending 0.4 × length of tergite … Ismarus excavatus Kim & Lee sp. nov.

10. POL longer than OOL (Fig. 3C); A7-A13 quadrate, as long as wide each segment (Fig. 3A); notauli present anteriorly as large pits (Fig. 3D) ……………………… Ismarus brevis Kim & Lee sp. nov.

- POL as long as OOL; A7-A13 longer than wide each segment (Fig. 2E); notauli present anteriorly, as oblique, elongate pits …………………………………………… Ismarus halidayi Förster, 1850