Subgenus Parachelonus Tobias, 1995

Diagnosis. Body large-sized, at least 5.0 mm; head transverse; antennomeres of both sexes more than 20, rarely less; eye densely setose; frons and vertex striate-rugose; face flat, transverse to irregular punctate-rugose; clypeus often finely punctate, shiny; mesoscutum and scutellum evenly convex, punctate to alveolate-rugose; propodeum coarsely rugose; vein 1-SR+M of fore wing absent; hind coxa, femur and apex of tibia comparatively robust; metasomal carapace of male with deep apical opening, carapace apically usually rounded in dorsal view, rarely narrowed posteriorly.

Biology. Parasitoids of Sesiidae and Tortricidae (Yu et al. 2016) .

Distribution. Palaearctic and Oriental regions (Yu et al. 2016).

Key to species of subgenus Parachelonus Tobias, 1995

1 Mesosoma reddish yellow (Figs 90B, 90C, 98B, 98C); [apical aperture of male carapace large, about 2.5 × wider than high (Figs 92F, 100F), its middle process of apical aperture moderately wide in lateral view (Figs 92D, 100D)]............... 2

- Mesosoma black (Figs 94B, 94C)........................................................................ 3

2 Temples distinctly widened behind eyes in dorsal view (Fig. 92H); body length 7.7–8.3 mm (Figs 89, 91); apex of metasomal carapace strongly incurved ventrally (Figs 90D, 92D)................. C. (P.) compressor (Chen & Ji, 2003) comb. nov.

- Temples narrowed behind eyes in dorsal view (Figs 98G, 100H); body length 4.0– 5.5 mm (Figs 97, 99); apex of metasomal carapace hardly incurved ventrally in female (Fig. 98D) and moderately so in male (Fig. 100D)...................................................................................... C. (P.) polycolor (Chen & Ji, 2003) comb. nov.

3 Females ............................................................................................. 4

- Males.............................................................................................. 9

4 Body length 7.9–8.5 mm; [vein 1-R1 of fore wing as long as pterostigma; lateral teeth of propodeum distinctly developed; antennomeres of female 41].................................... C. (P.) macrocorpus (Ji & Chen, 2003) comb. nov.

- Body length 4.8–5.3 mm (Fig. 93)........................................................................ 5

5 Temples rectilinearly narrowed behind eyes in dorsal view; face about 1.5 × wider than high.................................................................................................... C. (P.) gravenhorstii (Nees, 1816)

- Temple parallel-sided or slightly widened behind eyes; face more than 1.5 × wider than high (Fig. 94G)................ 6

6 Legs dark brown or black (Fig. 93)....................................................................... 7

- Legs pale or yellowish brown............................................................................ 8

7 Temples widened behind eyes in dorsal view; vein 1-R1 of fore wing as long as pterostigma; antennomeres of female 22................................................................................ C. (P.) pellucens (Nees, 1816)

- Temples parallel-sided behind eyes in dorsal view (Fig. 94G); vein 1-R1 of fore wing shorter than pterostigma (Fig. 94A); antennomeres of female 27 (Fig. 94H)................................................... C. (P.) hirsutus sp. nov.

8 Face 2.2 × wider than high; vein 1-R1 of fore wing shorter than pterostigma; antennomeres of female 20–22........................................................................................... C. (P.) starki (Telenga, 1953)

- Face 1.6 × wider than high; vein 1-R1 of fore wing as long as pterostigma; antennomeres of female18........................................................................................... C. (P.) xanthofossa (Tobias, 2000)

9 Mesopleuron entirely densely setose (Fig. 96B); [apical aperture in posterior view occupying about 0.5 × metasomal width (Fig. 96F); antennomeres of male 30 (Fig. 96I)]............................................... C. (P.) hirsutus sp. nov.

- Mesopleuron only setose below......................................................................... 10

10 Apical aperture in posterior view elongate, slit-shaped (width: height ratio> 3.5 ×)................................ 11

- Apical aperture in posterior view oval or round (width: height ratio <3.5 ×)...................................... 12

11 Length of 3 rd and penultimate antennomeres 3.7–3.8 × and 1.7–1.8 × its width, respectively; lateral teeth of propodeum strong and comparatively large.......................................................... C. (P.) starki (Telenga, 1953)

- Length of 3 rd and penultimate antennomeres 3.3 × and 1.3–1.5 × its width, respectively; lateral teeth of propodeum weak and small........................................................................ C. (P.) pellucens (Nees, 1816)

12 Legs yellowish brown; [antennomeres of male 23–24; metasomal carapace in dorsal view gradually widened]..................................................................................... C. (P.) xanthofossa (Tobias, 2000)

- Legs dark brown or black.............................................................................. 13

13 Temples rectilinearly narrowed behind eyes in dorsal view; carapace entirely black....... C. (P.) gravenhorstii (Nees, 1816)

- Temple parallel-sided or slightly widened behind eyes; base of metasomal carapace with a yellow band or a pair of yellowish lateral spots......................................................................................... 14

14 Vein 1-R1 of fore wing as long as pterostigma; base of metasomal carapace with a pair of yellowish lateral spots; temples slightly narrowed behind eyes in dorsal view.......................................... C. (P.) ovalis (Tobias, 1984)

- Vein 1-R1 of fore wing shorter than pterostigma; base of metasomal carapace with a yellow band; temples widened behind eyes in dorsal view............................................................ C. (P.) magnipunctus (Tobias, 1984)