Lepisiota

Mostafa R. Sharaf, Joe Monks, Andrew Polaszek & Abdulrahman S. Aldawood, 2016, A remarkable new species of the genus Lepisiota Santschi (Hymenoptera: Formicidae) from Oman and the United Arab Emirates with a key to the Arabian species, Journal of Natural History 50 (29), pp. 1875-1887 : 8-11

Key to Arabian species of Lepisiota

Modified from Collingwood and Agosti (1996).

1. Antennal scape long, surpassing the posterior margin of head by half its length or more ............................................................................................................................................................ 2

– Antennal scape shorter, surpassing the posterior margin of head by a third of its length or less ......................................................................................................................................... 18

2. Dorsum of mesosoma and gaster without standing setae; antennal scape exceptionally long; SI ˃ 200 .................................................................................................................................................. 3

– Dorsum of mesosoma with at least one or two pairs of long setae on pronotum; gaster always with some projecting setae; antennal scape shorter; SI <200 ............ 4

3. Unicolourous dark brown or black-brown; body parts of moderate lengths (SI 200 – 205; WL 1.00) ( KSA).................................................... .................................................... riyadha

– Bicoloured species, head and gaster brown; body exceptionally long (SI ˃ 375; WL 1.91) ( Oman, UAE).................................................... .................................................... elegantissima

4. Bicoloured, mesosoma paler than gaster, mainly or entirely reddish ........................... 5 – Whole body dark except a small area of the mesonotum more or less red in a few species....................................................................................................................................................... 10

5. Mesosoma with whole dorsum covered with blunt black setae ( KSA) ............ arabica

–

Mesosoma with one, two or three pairs of fine setae on the pronotum ...................... 6

6. Body sculpture coarse, general appearance opaque ............................................................ 7 –

All parts of the body shining with superficial reticulate sculpture at most.................. 8

7. Colour entirely black; several pairs of long, pale setae on cephalic dorsum, pronotum and gaster; petiole wide, at least 0.33 × HW ( Afghanistan, India)........................ sericea

– Bicoloured species, head, mesosoma, petiole and appendages orange, gaster dark brown; body pilosity rare except for long few setae on anterior clypeal margin and sparse appressed pubescence on cephalic dorsum; petiole narrower, less than 0.30 × HW ( Greece, India, Iran, Israel, Lebanon)................................... ................................... bipartita

8. Head and mesosoma uniformly red; propodeum armed with long curved spines ( Oman, Zimbabwe) ........................................................ ........................................................ arenaria

– Head darker than mesosoma; propodeum simply dentate, or armed with short, straight spines ........................................................................................................................................ 9

9. Head, petiole and gaster light brown, mesosoma and appendages yellow; mesonotum distinctly narrower anteriorly than posteriorly in dorsal view; propodeal and petiolar spines acute ( KSA) .................................................................................................................. dammama

– Head, petiole and gaster dark brown contrasting with the red mesosoma;

mesonotum characteristically rectangular in dorsal view; propodeal and petiolar spines blunt ( Greece, Iran, Israel, KSA, Turkey) .................................................... dolabellae

10. Mesosoma densely sculptured; not shining ................................................................ 11

– Mesosoma superficially sculptured; at least partially shining, in some species completely shining ................................................................................................................ 12

11. Head and mesosoma densely sculptured and completely opaque; propodeal spines long and curved; first and second gastral tergites with a few pairs of long setae located at posterior margins of tergites ( Oman) .............. dhofara

– Head and mesosoma superficially sculptured and slightly shining; propodeal armature short and blunt; first and second gastral tergites completely bare (Balkan Peninsula, Central Asia, Iran, Kazakhstan, Kuwait, UAE) karawaiewi

12. Body entirely black, with slight reticulate sculpture at most and shining ............... 13

– Mesosoma usually with small area of mesonotum red; head and mesosoma distinctly sculptured and not shining ................................................................................................................. 17

13. Propodeal spines short and straight, petiole dorsum narrow and rounded, with reduced armature; antennal scapes shorter, SI 150 – 155 ( Croatia, Egypt, Greece, Iberian Peninsula, Italy, Kyrgyzstan, Macedonia, Montenegro, Oman, UAE) ... nigra

– Propodeal and petiolar armature both well developed with long curved spines; antennal scape long, SI 165 – 200 ............................................................................................... 14

14. Propodeum and first gastral tergite with some fine surface sculpture; first gastral tergite with characteristic violet reflection; S1 195 – 200 ( Egypt, Israel, KSA, UAE) ........ ................................................................................................................................................ opaciventris

– Whole body smooth; first gastral tergite without reflection of any type; SI 165 – 195 .......................................................................................................................................... 15

15. Propodeal short, less than 0.10 mm, moderately curved; antennal scape long, SI 175 – 195 ( Yemen, Eritrea, Israel, UAE).................................. .................................. gracilicornis

– Propodeal spines long, more than 0.12 mm, and distinctly curved; antennal scape shorter, SI 165 – 170............................................................................................................................. 16

16. Body dark brown; propodeal spines shorter and slightly curved, in profile appearing at level of the petiolar spines; body slightly shining; scape shorter (SI 170), cephalic index smaller (CI 79), petiolar height lower in profile (0.41); appressed pubescence abundant on body ( Kazakhstan, Oman, KSA, Socotra) ...... .................................................................................................................................. spinisquama – Body black, propodeal spines longer and more strongly curved, in profile appearing much higher than level of petiolar spines; body more strongly shining; scape longer (SI 230 – 233), cephalic index greater (CI 86 – 88), petiolar height larger in profile (0.25 – 0.37); pubescence on body scattered ( Oman, UAE) ........... ........... omanensis sp. nov.

17. Pronotum with one pair of setae; petiole dorsum distinctly dentate (widespread in Palaearctic region)...................................................... ...................................................... frauenfeldi

– Pronotum without setae; petiole dorsum feebly incavate or narrowly rounded without teeth ( Tunisia, UAE) ................................................ ................................................ nigrescens

18. Head and gaster smooth and shining with only faint sculpture .................................. 19

– Head and gaster distinctly sculptured ....................................................................................... 21

19. Whole body dorsum covered with blunt black setae ( Namibia, Somalia, Yemen, Zimbabwe) ........................................................................................................................ validiuscula

– Mesosoma with pale, thin setae ................................................................................................. 20

20. Body pilosity short, restricted to a few pairs, sparse on propodeum and gastral tergites; pronotum without setae; whole body smooth and shining ( Bangladesh, India, Kenya, KSA, Lesotho, Somalia, Zimbabwe) ................................ simplex stat. nov.

– Body pilosity long and abundant, especially on gaster; pronotum with five pairs of hairs; whole body smooth except mesopleura transversely striate, general appearance moderately shining ( Guinea, Israel, Kenya, KSA, Somalia, Oman, Yemen............... ..................................................................................................................................................... canescens

21. Whole mesosomal dorsum covered with long pale setae ( Eritrea, Israel, KSA, Oman, Yemen) .......................................................................................................................................... obtusa

– Pilosity on mesosomal dorsum either restricted to pronotum or absent ................. 22

22. Petiolar angles produced into long spines ............................................................................. 23

– Petiole dorsum flat, emarginate or dentate at most ......................................................... 24

23. Larger species, TL 3.30; head superficially sculptured, slightly shining; in full-face view posterior margin of head strongly convex and with three pairs of long, stiff setae; mesosoma with several pairs of setae, smooth and shining, except for transverse striations on mesopleura ( Democratic Republic of Congo, Kenya, Yemen) ...................................................................................................................................... incisa

– Smaller species, TL 2.12; head strongly sculptured, completely opaque; in full-face view posterior margin of head straight, without setae; mesosoma without setae, entirely, and densely sculptured ( Djibouti, KSA, Oman, Somalia, Yemen) .................................... carbonaria

24. Petiolar armature well developed; gaster finely and densely granulate, completely opaque ( Eritrea, Ethiopia, KSA, Yemen) .................................................................... erythraea

– Petiolar dorsum shallowly emarginate; gaster superficially sculptured, slightly but distinctly shining ................................................................................................................................ 25

25. Mesosoma red; first gastral tergite with six pairs of long, pale setae located dorsally, posterior margin with several pairs; smaller species (TL 2.80), scape longer (SI 123) and head slightly narrower (HW 0.57) ( Yemen) ............................ ............................ harteni

– Mesosoma brown; pilosity of first gastral restricted to posterior margin; larger species (TL 3.20), scape shorter (SI 111), head wider (HW 0.63) ( KSA, Oman, Somalia) ........ depilis