Genus Enicospilus Stephens, 1835

A total of 498 specimens of Enicospilus representing 23 species were collected and identified with the keys of Gauld & Mitchell (1978) and Rousse & van Noort (2014). Some uncertain identifications were confirmed with the help of Gavin Broad (NHMUK). All our sequences and related pictures were uploaded to the BOLD database, and the identification numbers are detailed in the relevant descriptions (see below). The DNA extraction was unsuccessful for E. senescens (Tosquinet, 1896) and not enough material was available at the moment of extraction of E. bicoloratus Cameron, 1912, E. perlatus, E. psammus, Enicospilus sp. 1 and sp. 2. Six of the 17 COI barcodes significantly matched (> 97% similarity) with databased sequences, all of which were registered as unidentified Enicospilus spp. in the BOLD database. These were the barcodes extracted from specimens morphologically identified as E. capensis, E. grandiflavus Townes & Townes, 1973, E. oculator, E. pacificus (Holmgren, 1868), E. pallidus (Taschenberg, 1875) and E. shadaensis sp. nov.

Five new species are described herein: E. arabicus Gadallah & Soliman sp. nov., E. mirabilis Soliman & Gadallah sp. nov., E. pseudoculator Gadallah & Soliman sp. nov., E. shadaensis Gadallah & Soliman sp. nov. and E. splendidus Rousse, Soliman & Gadallah sp. nov. In addition, this paper documents twelve species newly recorded from Saudi Arabia. Most of the reported species are typical of the Afrotropical region rather than the Palaearctic region, especially those collected from Al Baha and Asir provinces (southwestern Saudi Arabia). Of the Saudi species of Enicospilus, 86.9% are Afrotropical, 8.7% are Palaearctic and 13% are both ( E. capensis, E. psammus, E. pseudoculator sp. nov.) (Table 1). Interestingly, two species reported from Yemen ( E. justus and E. expeditus) (Gauld & Mitchell 1978) were not collected in the present study from South Western Saudi Arabia. An explanatory hypothesis might be that these two species were collected only in the high mountains in Yemen. As a consequence, we can not ascertain their presence in Saudi Arabia and did not include them in the key.

Key to the species of Enicospilus in Saudi Arabia

1. Disco-submarginal cell of fore wing without any alar sclerites (Figs 25C, 27B) ............................ 2 – Disco-submarginal cell of fore wing with one or more alar sclerites ............................................... 3

2. Rs+2 r strongly sinuate proximally, fenestra relatively small, AI> 1 (Fig. 27B); antenna with more than 65 flagellomeres ........................................................................ E. senescens (Tosquinet, 1896)

– Rs+2 r straighter proximally (Fig. 25C), fenestra larger, AI <1; antenna with fewer than 65 flagellomeres .................................................................................. E. oweni Gauld & Mitchell, 1976

3. Mesosoma interspersed with ivory markings (Figs 3H, 4B, 4G, 5B, 5C); antenna relatively short with fewer than 55 flagellomeres ...................................................................................................... 4

– Mesosoma uniformly coloured, without ivory markings; antenna variable, usually with more than 55 flagellomeres ..................................................................................................................................... 8

4. Fore wing with one proximal sclerite, central sclerite totally absent (Figs 26C, 27C, 28A) ........... 5

– Fore wing with one proximal and one central sclerite (Figs 24B, 25A) ........................................... 7

5. Proximal sclerite very weakly sclerotized (Fig. 28A); outer mid tibial spur very short, less than 0.4 × as long as inner spur (Fig. 33C)....................... E. splendidus Rousse, Soliman & Gadallah sp. nov.

– Proximal sclerite fully sclerotized (Figs 26C, 27C); outer mid tibial spur usually longer ............... 6

6. Body dark reddish brown (Fig. 5B); proximal sclerite dark brown to black, triangular, CI> 0.2 (Fig. 27C); face narrow, 1.5 × higher than wide (Fig. 8F); moderately large species (B> 27, F> 12) ............................................................................ E. shadaensis Gadallah & Soliman sp. nov.

– Body lighter orange to brown (Fig. 4G); proximal sclerite bright red and dome-shaped, CI <0.2 (Fig. 26C); face subquadrate, 1.1 × higher than wide (Fig. 8C); smaller species (B <19, F <12) ...................................................................... E. pseudoculator Gadallah & Soliman sp. nov.

7. Metasoma interspersed with ivory markings (Fig. 3H); central sclerite uniformly sclerotized (Fig. 24B); median flagellomeres stout (Fl20 <1.7) ........ E. mirabilis Soliman & Gadallah sp. nov.

– Metasoma without ivory markings (Fig. 4B); central sclerite weakly sclerotized proximally (Fig. 25A); median flagellomeres more slender (Fl20> 1.7) ...................... E. oculator Seyrig, 1935

8. Proximal sclerite acutely arrow-shaped, central sclerite very weakly sclerotized (Fig. 25B); moderately to very large species (B 16–30, F 14–20) .................... E. odax Gauld & Mitchell, 1978

– Proximal sclerite obviously different, central sclerite present or absent; usually smaller species ... 9

9. Central sclerite totally absent, without even a faint trace (Figs 22A, 22C, 23C, 24A) .................. 10

– Central sclerite present (e.g., Figs 22B, 23B, 26A, 26B, 28C) though sometimes weakly sclerotized (e.g., Figs 23A, 24C, 28C) .............................................................................................................. 13

10. Pale yellow species (Figs 3A, 3G) ...................................................................................................11

– Darker yellowish-orange species (Figs 3C, 3E) ............................................................................. 12

11. Proximal sclerite obtusely angled without distal extension, ICI> 0.6, CI <0.3 (Fig. 24A); propodeum coarsely and concentrically striate (Fig. 19A); clypeus flat in profile; metasoma darkened dorsally and apically (Fig. 3G); large species (B> 25, F> 15) ....................................................................... ........................................................................................... E. grandiflavus Townes & Townes, 1973

– Proximal sclerite comma-shaped with very long distal extension, ICI <0.6, CI> 0.3 (Fig. 22A); integument is almost longitudinally striate just behind the basal transverse carina of propodeum (Fig. 18A); clypeus very strongly convex in profile (Fig. 10A); metasoma uniformly yellow without any dark markings (Fig. 3A); smaller species (B <25, F <15) ......................................................... ........................................................................................... E. arabicus Gadallah & Soliman sp. nov.

12. Antenna moderately long with more than 50 flagellomeres, median ones strongly elongate (Fl20> 2); metapleuron weakly convex, without punctures, and longitudinally striate ................................. ................................................................................................................ E. dubius (Tosquinet, 1896)

– Antenna short with fewer than 50 flagellomeres, median ones stout (Fl20 <2); metapleuron strongly convex, puncto-striate and longitudinally striate .................................... E. brevicornis (Masi, 1939)

13. Central sclerite subdivided and U-shaped (Fig. 23B) ................................. E. divisus (Seyrig, 1935)

– Central sclerite not elongate, obviously different ........................................................................... 14

14. Proximal sclerite rather narrow, comma-shaped with very long distal extension, central sclerite uniformly sclerotized (Fig. 26A) ....................................................... E. pacificus (Holmgren, 1868)

– Proximal sclerite different, more or less triangular sometimes with a faint distal extension (e.g., Figs 22B, 23A, 26B, 28C); central sclerite sometimes weakly sclerotized (e.g., Figs 23A, 24C, 28C) ................................................................................................................................................ 15

15. Central sclerite crescent-shaped, weakly sclerotized proximally, and large with maximal length larger than distance to Rs+2r (Fig. 26B); pale yellow species (Fig. 4F) ............................................ .......................................................................................................... E. pallidus (Taschenberg, 1875)

– Central sclerite smaller and more or less circular (e.g., Figs 22B, 23A, 28B), sometimes hardly sclerotized proximally and/or distinctly elongate (Figs 24C, 27A) but never crescent-shaped; usually darker yellowish-orange species ..................................................................................................... 16

16. Very small species (F 6–9), with characteristic alar sclerites (Fig. 34A) ........................................... .................................................................................................. E. psammus Gauld & Mitchell, 1978

– Larger species (F nearly always> 10), with different alar sclerites ............................................... 17

17. Outer mid (and sometimes hind) tibial spur(s) very short, less than 0.4 × as long as inner spur(s) (Figs 33A); central sclerite longitudinal and weakly sclerotized (Fig. 24C) ...................................... ................................................................................................................ E. nervellator Aubert, 1966

– Outer mid and hind tibial spurs longer; central sclerite variable .................................................... 18

18. Mandible with a long piliferous furrow from dorsal base to between teeth (Fig. 10D) ................. 19

– Mandible without such a distinct piliferous furrow (e.g., Fig. 13B) .............................................. 20

19. Mandible with upper tooth less than twice the length of lower tooth (Fig. 6B), bare or sparsely setose on outer margin (Fig. 6B); central sclerite small, circular, and uniformly sclerotized (Fig. 22B) ............................................................................................ E. bicoloratus Cameron, 1912

– Mandible with upper tooth more than twice the length of lower tooth (Fig. 6D), with dense setae on outer margin (Figs 6D, 10D); central sclerite not uniformly sclerotized (Fig. 23A) .......................... .............................................................................................................. E. capensis (Thunberg, 1822)

20. Central sclerite small, shortly elongate and totally translucent (Fig. 34B); hind wing with Cu & cu-a (nervellus) intercepted around middle (NI 1.0–1.2) .............................. E. perlatus Shestakov, 1926

– Central sclerite circular to distinctly elongate, pigmented at least distally (Figs 27A, 28 B–C); hind wing with Cu & cu-a (nervellus) intercepted far below middle (NI> 1.6) .................................... 21

21. Central sclerite moderately to very long and curved toward base of wing, proximal sclerite dark brown (Fig. 27A) .................................................................................. E. rundiensis Bischoff, 1915

– Central sclerite more or less circular, proximal sclerite lighter (Figs 28 B–C) ............................... 22

22. Central sclerite weakly sclerotized proximally (Fig. 28C); mesopleuron closely punctate without longitudinal striations (Fig. 17C) ............................................................................ Enicospilus sp. 1

– Central sclerite fully sclerotized (Fig. 28B); mesopleuron puncto-striate........................................... .............................................................................. Enicospilus sp. 2 cf. bicoloratus Cameron, 1912