Gonatocerus (Lymaenon) Walker 1846

Subgenus Gonatocerus (Lymaenon Walker, 1846)

Lymaenon Walker 1846: 49–50.

Type species: Lymaenon acuminatus Walker, by subsequent designation by Gahan & Fagan 1923: 82.

Rachistus Foerster 1847: 203.

Type species: Ooctonus litoralis Haliday, by subsequent designation by Gahan & Fagan 1923: 128.

Rhachistus Dalla Torre 1898: 429. Unjustified emendation of Rachistus Foerster.

Oophilus Enock 1909: 458.

Type species: Oophilus longicauda Enock, by monotypy.

Agonatocerus Girault 1913a: 276.

Type species: Agonatocerus humboldti Girault, by original designation.

Gonatoceroides Girault 1913b: 255 (as subgenus of Gonatocerus).

Type species: Gonatocerus (Gonatoceroides) australicus Girault [as australica], by original designation.

Lymaenon Walker (litoralis species group): Debauche 1948: 80, 82; Debauche 1949: 27.

Lymaenon Walker (unnamed group 4): Debauche 1948: 82.

Decarthrius Debauche 1949: 21–22.

Type species: Decarthrius straeleni Debauche, by original designation.

Gonatocerus Nees (contortivena species group): Debauche 1949: 26.

Gonatocerus Nees (acuminatus species group [= Oophilus Enock]): Debauche 1949: 26, 33.

Oophilus Enock: Kryger 1950: 79 –81.

Gonatocerus (Gonatocerus Nees): De Santis 1967: 103 –105 (in part).

Gonatocerus (Lymaenon Walker): Herting 1972: 14; Triapitsyn et al. 2010: 41–42 (reinstated as a valid subgenus, synonymy, diagnosis, key to species in the Neotropical region).

Gonatocerus Nees (litoralis species group): Matthews 1986: 216 (key), 222–223; Huber 1988: 30 –32; Yoshimoto 1990: 37 – 38; Zeya & Hayat 1995: 91 –94 (diagnosis, key to Indian species); Donev 2005: 380 (key to species in the Balkan Peninsula); Pricop 2010c: 78 (diagnosis, illustrations).

Gonatocerus Nees (straeleni species group, without a formal synonymy of Decarthrius [then a synonym of Gahanopsis Ogloblin] under Gonatocerus): Huber 1988: 24; Yoshimoto 1990: 37.

Lymaeaon [sic] Walker: Guo et al. 2011: 54 (misspelled).

Diagnosis. Pronotum divided into 2 lobes widely separated by lightly sclerotized median area, except narrowly separated in a few Afrotropical species and median area sometimes strongly sclerotized in some Australasian species; female funicle usually 8-segmented, rarely 7-segmented (mostly in some Afrotropical species); dorsellum strap-like, with posterior margin more or less straight and parallel with anterior margin; propodeum with submedian lines instead of a median carina or submedian carinae (except in some Afrotropical species) and the area between them flat and often bearing minute spicules (as in Fig. 197); fore wing with cubital row (at least) of setae extending to base of marginal vein (except in G. (Lymaenon) karakum from Italy and Turkmenistan (Fig. 101) and some Afrotropical and Australasian species).

Distribution. Cosmopolitan.

Hosts. Reliable host records of G. (Lymaenon) are from eggs of Cicadellidae and Membracidae.

Comments. It has been a challenge to compile a key to separate females of the Palaearctic species of G. (Lymaenon) because of variability of some traditionally used diagnostic features; good slide mounts of wellcleared specimens are thus particularly needed in this subgenus to be able to see and assess the characters used in the key, descriptions, and redescriptions.

Key to females of Palaearctic species of Gonatocerus (Lymaenon)

1 Ovipositor projecting anteriorly under mesosoma and extending to posterior margin of anterior scutellum (Fig. 182)........................................................................................ G. (Lymaenon) svat sp. n.

– Ovipositor at most extending anteriorly to posterior margin of propodeum........................................ 2

2(1) Ovipositor exserted beyond gastral apex by 0.35× own length (Fig. 130)..................... G. (Lymaenon) kum sp. n.

– Ovipositor exserted beyond gastral apex by at most 0.25× own length............................................ 3

3(2) Ovipositor notably exserted beyond gastral apex by 0.15–0.25× own length....................................... 4

– Ovipositor not or only slightly exserted beyond gastral apex by at most 0.11× own length............................ 6

4(3) Fore wing disc with a large, distinct bare area between marginal vein and cubital row of setae (Fig. 54).......................................................................................... G. (Lymaenon) acuminatus (Walker)

– Fore wing disc setose between marginal vein and cubital row of setae............................................ 5

5(4) Fore wing wide, at most 2.9× as long as wide (Fig. 135)................................ G. (Lymaenon) kusaka sp. n.

– Fore wing narrow, at least 4.2× as long as wide (Fig. 175)............................. G. (Lymaenon) novickyi Soyka

6(3) Fore wing with cubital row of setae not extending to base of marginal vein (Fig. 101)........ G. (Lymaenon) karakum sp. n.

– Fore wing with cubital row of setae extending to base of marginal vein........................................... 7

7(6) Ovipositor extending anteriorly to posterior margin of propodeum (Figs 118, 126).................................. 8

– Ovipositor not extending anteriorly to posterior margin of propodeum (e.g., Figs 70, 73, 146)......................... 9

8(7) F5 with 2 mps; clava with at least 9 mps.......................................... G. (Lymaenon) kulik sp. n. (part)

– F5 without mps; clava with 8 mps................................................. G. (Lymaenon) komarik sp. n.

9(7) Fore wing relatively narrow, at least 3.9× as long as wide.................................................... 10

– Fore wing relatively wide, at most 3.8× as long as wide...................................................... 13

10(9) Clava with 6 mps.............................................................. G. (Lymaenon) aureus Girault

– Clava with at least 8 mps.............................................................................. 11

11(10) Body length about 1.5 mm; ovipositor 2.9× length of mesotibia............................ G. (Lymaenon) kalika sp. n.

– Body length at most about 1.0 mm; ovipositor at most 1.8× length of mesotibia................................... 12

12(11) Fore wing 4.4× as long as wide; disc with setae sparse between marginal vein and cubital row of setae leaving a small, indistinct bare area (Fig. 93)..................................................... G. (Lymaenon) cunctator (Mathot)

– Fore wing at most 4.1× as long as wide; area on disc between marginal vein and cubital row of setae more or less densely setose and without a bare area (as in Fig. 150).................................. G. (Lymaenon) litoralis (Haliday) (part)

13(9) Clava with at least 11 mps............................................................................. 14

– Clava with at most 10 mps............................................................................. 17

14(13) Ovipositor at least 2.2× length of mesotibia....................................... G. (Lymaenon) kulik sp. n. (part)

– Ovipositor at most 2.0× length of mesotibia............................................................... 15

15(14) Fore wing (Fig. 109) disc with a usually large and distinct bare area between marginal vein and cubital row of setae (a row of setae always present next to marginal vein and occasionally additional, sparse setae behind marginal vein so that bare area sometimes less distinct)..................................................... G. (Lymaenon) katraps sp. n. (part)

– Fore wing disc densely setose between marginal vein and cubital row of setae (Figs 123, 179)....................... 16

16(15) Head mostly yellowish except vertex variably brownish and brown around ocelli and trabeculae dark brown, mesosoma usually mostly orange to light brown with some brown on scutellum and sometimes also on midlobe of mesoscutum (Fig. 121); ovipositor at least 1.1× length of mesotibia........................................ G. (Lymaenon) krasavchik sp. n.

– Head and mesosoma dark brown; ovipositor 0.9× length of mesotibia................. G. (Lymaenon) saulfrommeri sp. n.

17(13) Clava with 10 mps (4 of them more or less in middle of clava, best observed in lateral view)........................ 18

– Clava with at most 9 mps.............................................................................. 23

18(17) Fore wing disc with a more or less distinct bare area between marginal vein and cubital row of setae or area between marginal vein and cubital row of setae with setae sparse............................................................. 19

– Fore wing disc more or less densely setose between marginal vein and cubital row of setae (Fig. 148)........................................................................................ G. (Lymaenon) litoralis (Haliday) (part)

19(18) F5–F8 each with at least 2 mps......................................................................... 20

– At least one funicle segment among F5–F8 with less than 2 mps on both antennae................................. 21

20(19) Head and mesosoma black, gaster mostly dark brown; fore wing 2.7–3.1× as long as wide G. (Lymaenon) katraps sp. n. (part)

– Head and mesosoma mostly brown, gaster yellowish basally and brown distally; fore wing about 3.3× as long as wide.......................................................................... G. (Lymaenon) vidanoi (Viggiani & Jesu)

21(19) Ovipositor at least 1.7× length of mesotibia......................................... G. (Lymaenon) longior Soyka

– Ovipositor at most 1.6× length of mesotibia............................................................... 22

22(21) F5 with 1 mps......................................................................... G. (Lymaenon) sp. 1

– F5 without mps........................................................... G. (Lymaenon) thyrides (Debauche)

23(17) Fore wing with longest marginal seta at least 0.51 maximum wing width.................... G. (Lymaenon) karlik sp. n.

– Fore wing with longest marginal seta at most 0.4× maximum wing width........................................ 24

24(23) Ovipositor at least 2.2× length of mesotibia....................................... G. (Lymaenon) kulik sp. n. (part)

– Ovipositor at most 1.8× length of mesotibia............................................................... 25

25(24) Fore wing disc with a large, distinct bare area between marginal vein and cubital row of setae (Fig. 90).......................................................................................... G. (Lymaenon) bicoloriventris Zeya

– Fore wing disc without such bare area, sparsely to densely setose between marginal vein and cubital row of setae........ 26

26(25) F8 with 4 mps, clava with 9 mps..................................................... G. (Lymaenon) ucri sp. n.

– F8 with 2 mps, clava with 8 mps........................................................................ 27

27(26) Mps present at least on F5–F8.......................................................................... 28

– Mps present at most on F6–F8 (usually only on F7 and F8)............................... G. (Lymaenon) kazak sp. n.

28(27) Ovipositor at most 1.3× length of mesotibia....................................... G. (Lymaenon) africanus Soyka

– Ovipositor at least 1.7× length of mesotibia............................................................... 29

29(28) F4 with 1 or 2 mps; fore wing 3.2× as long as wide................................ G. (Lymaenon) berezovskiyi sp. n.

– F4 without mps; fore wing at most 2.9× as long as wide............................. G. (Lymaenon) beshbarmak sp. n.