Subgenus Stylochelonus Hellén, 1958
Diagnosis. Head transverse; antennomeres of both sexes more than 16, often distinctly widened medially in females; eye densely setose; frons and vertex very coarsely rugose; face flat, either striate-rugose or reticulate-rugose; clypeus often finely punctate, with distinct setosity and shiny; mesoscutum and scutellum evenly convex, densely alveolate-rugose; propodeum coarsely rugose; vein 1-SR+M of fore wing absent; hind coxa, femur and apex of tibia distinctly robust; metasomal carapace of male with small apical opening, which may be filled by point-like sclerite; carapace of female usually with an apical tooth; carapace apically usually rounded in dorsal view, rarely narrowed posteriorly.
Biology. Parasitoids of Elachistidae and Tortricidae (Yu et al. 2016) .
Distribution. Worldwide (Yu et al. 2016).
Key to species of subgenus Stylochelonus Hellén, 1958
1 Females ............................................................................................. 2
- Males............................................................................................. 14
2 Carapace of female without an apical tooth in dorsal view (Fig. 102E)........................................... 3
- Carapace of female with an apical tooth in dorsal view (Fig. 106E).............................................. 4
3 Temples strongly narrowed behind eyes in dorsal view; head 2.5 × wider than long in dorsal view (Fig. 102G); legs dark (Fig. 101)............................................................................. C. (S.) acaretrus sp. nov.
- Temple almost parallel-sided behind eyes in dorsal view; head 1.6 × wider than long in dorsal view; legs pale...................................................................................... C. (S.) interpositus (Tobias, 1995)
4 Legs pale or yellowish brown (Fig. 105)................................................................... 5
- Legs dark brown or black............................................................................... 9
5 Temples distinctly widened behind eyes in dorsal view; [vein 1-R1 of fore wing shorter than pterostigma]............... 6
- Temples parallel-sided or slightly narrowed behind eyes in dorsal view (Fig. 106G)................................. 7
6 Length of 3 rd antennomere 4.0 × its width; mesosoma 1.3 × longer than high in lateral view................................................................................................. C. (S.) mucronatus (Thomson, 1874)
- Length of 3 rd antennomere 3.0 × its width; mesosoma 1.7 × longer than high in lateral view. C. (S.) pedator (Dahlbom, 1833)
7 Vein 1-R1 of fore wing shorter than pterostigma; vein r of fore wing straight (Fig. 106A)...... C. (S.) punctulosus sp. nov.
- Vein 1-R1 of fore wing as long as or longer than pterostigma; vein r of fore wing curved............................. 8
8 Mesosoma 1.5 × longer than high in lateral view; face 2.0 × wider than high............ C. (S.) pusillus (Szépligeti, 1908)
- Mesosoma 1.7 × longer than high in lateral view; face 1.5 × wider than high............. C. (S.) elachistae (Tobias, 1995)
9 Temples distinctly widened behind eyes in dorsal view....................................................... 10
- Temples parallel-sided or slightly narrowed behind eyes in dorsal view.......................................... 12
10 Vein 1-R1 of fore wing longer than pterostigma; penultimate antennomere shorter than wide.. C. (S.) koponeni (Tobias, 1995)
- Vein 1-R1 of fore wing as long as or shorter than pterostigma; penultimate antennomere as long as wide or longer....... 11
11 Penultimate antennomere as long as wide; antennomeres of female 21–22................ C. (S.) karadagi (Tobias, 1995)
- Penultimate antennomere longer than wide; antennomeres of female 23................ C. (S.) subpedator (Tobias, 1995)
12 Posterior excavation of head deep; antennomeres of female 17; sculpture at base of carapace reticulate-rugose................................................................................ C. (S.) septemdecimplex (Tobias, 1986)
- Posterior excavation of head shallow; antennomeres of female 20; sculpture at base of carapace longitudinally rugose................................................................................ C. (S.) magadani (Tobias, 1994)
14 Carapace of male with an apical tooth in dorsal view (Fig. 108E)......................... C. (S.) punctulosus sp. nov.
- Carapace of male without an apical tooth in dorsal view (Fig. 104E)............................................ 15
15 Fifth-ninth antennomeres of male yellow and more distal antennomeres brown; antenna clearly widened beyond middle (Fig. 104I); [vein r of fore wing slightly curved (Fig. 104A); temples narrowed behind eyes in dorsal view (Fig. 104H)]......................................................................................... C. (S.) acaretrus sp. nov.
- Fifth-ninth antennomeres of male brown or dark brown as more or less distal antennomeres......................... 16
16 Legs pale or yellowish brown........................................................................... 17
- Legs dark brown or black.............................................................................. 19
17 Temples distinctly widened behind eyes in dorsal view; vein 1-R1 of fore wing shorter than pterostigma........................................................................................... C. (S.) pedator (Dahlbom, 1833)
- Temples parallel-sided or slightly narrowed behind eyes in dorsal view; vein 1-R1 of fore wing as long as pterostigma or longer............................................................................................. 18
18 Mesosoma 1.5 × longer than high in lateral view; metasomal carapace 2.0 × longer than wide in dorsal view....................................................................................... C. (S.) interpositus (Tobias, 1995)
- Mesosoma 1.7 × longer than high in lateral view; metasomal carapace 1.8–1.9 × longer than wide in dorsal view.................................................................................... C. (S.) elachistae (Tobias, 1995)
19 Apical aperture of carapace in posterior view large, occupying about 0.3 of carapace width.......................... 20
- Apical aperture of carapace in posterior view occupying 0.1–0.2 of carapace width................................ 21
20 Face narrow, about 1.6 × wider than high; mesosoma 1.5 × longer than high in lateral view.. C. (S.) lissofossa (Tobias, 2000)
- Face about 2.0 × wider than high; mesosoma 1.3 × longer than high in lateral view...... C. (S.) cariniventris (Tobias, 1996)
21 Apical aperture located in upper half of posterior part of metasomal carapace and oblique to horizontal plane; [vein 1-R1 of fore wing shorter than pterostigma; mesosoma 2.0 × longer than high in lateral view]............ C. (S.) elongatus (Papp, 1971)
- Apical aperture located in middle of posterior face of metasomal carapace and in vertical plane...................... 22
22 Vein 1-R1 of fore wing longer than pterostigma; [mesosoma 2.0 × longer than high in lateral view; apical aperture in posterior view occupying about 0.2 of metasomal carapace width].............................. C. (S.) koponeni (Tobias, 1995)
- Vein 1-R1 of fore wing as long as pterostigma or shorter..................................................... 23
23 Vein r of fore wing shorter than vein 3-SR; [antennomeres of male 23; apical aperture in posterior view occupying 0.18–0.23 of metasomal carapace width]................................................... C. (S.) karadagi (Tobias, 1995)
- Vein r of fore wing longer than vein 3-SR................................................................. 24
24 Face about 3.0 × wider than high; [antennomeres of male 25; mesosoma 1.5 × longer than high in lateral view]........................................................................................ C. (S.) clausus (Tobias, 1996)
- Face less than 2.0 × wider than high..................................................................... 25
25 Length of 3 rd antennomere 4.0 × its width; mesosoma 1.3 × longer than high in lateral view................................................................................................. C. (S.) mucronatus (Thomson, 1874)
- Length of 3 rd antennomere less than 3.5 × its width; mesosoma more than 1.5 × longer than high in lateral view......... 26
26 Face 2.0 × wider than high; metasomal carapace 1.8–1.9 × longer than wide in dorsal view..................................................................................................... C. (S.) pusillus (Szépligeti, 1908)
- Face 1.5 × wider than high; metasomal carapace 2.0–2.2 × longer than wide in dorsal view.................................................................................................... C. (S.) subpedator (Tobias, 1995)