Ants of Saudi Arabia

Ongoing studies by Mostofa Sharaf (King Saud University, Riyadh) are steadily consolidating past findings in contemporary taxonomic revisions. Many of Sharaf's new species descriptions are from specimens collected in his own field research and are published with Saudi centered generic-summaries and localized keys. Biological details from his first-hand field observations inlcuded in these taxonomic revisions are also adding important details to our knowledge of the ants in this region.

The generic accounts below may include country or regional specific text-summaries and links to species keys. There are species names on this page but are not meant to provide a complete faunal list (see Saudi Arabia). References and many citations are not included here as they are easily accessed elsewhere. The source and full set of references for each key, for example, are provided on the key webpage. The full reference for citations that are given below can be found on the respective author pages, e.g., Mostofa Sharaf.

Arabian Peninsula

Sharaf et al. (2020) - The Arabian Peninsula (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates, and Yemen) sits as a semi-isolated block between Eurasia and Africa that overlaps three of the world’s key zoogeographical regions; the Afrotropical (Ethiopian), the Oriental and the Palearctic (Larsen 1984; Delany 1989). It is, certainly, the only area where three such regions intersect. Through the Miocene to the Pliocene, it formed a land bridge between the Afrotropical and Oriental regions, allowing the interchange between the two faunas with a far stronger Afrotropical influence. The Afrotropical forms would have been forced out by invading Palearctic species following the severance of the land bridges and the lowering of temperatures during the Pleistocene glaciations, contracted into relict distributions, or evolved to become what are now southern Arabian endemics. The Palearctic species would have been forced northwards or into mountain refugia through the post-glacial increase in aridity and temperature and the remaining Afro-tropical species would have expanded their ranges.

Across through the Bab el Mandeb straits, further invasions from Africa may have been occurred, perhaps swamping such endemics, but invasions from the Oriental region seem have not occurred (Larsen 1980; Delany 1989). Land features affect species distribution and richness (Bestelmeyer and Schooley 1999; Boulton et al. 2005). Geographically, highlighting Oman, Al-Hajar mountains extended in Northeastern part. While, the Dhofar mountain range extend in the South East to Hadhramaut in Yemen. A large stretch of barren desert, acting as a zoogeographical barrier, lies between them. Boundaries among zoogeographical realms in the Arabian Peninsula is continuously a trending controversial topic (Larsen 1984; Rueda et al. 2013; El- Hawagry and Al Dhafer 2015; Ficetola et al. 2017; El-Hawagry et al. 2019).

The biogeography of the Arabian Peninsula has always been a subject of interest and sometimes controversial by researchers, and this is undoubtedly due to its geographic location at the interchange of three major zoogeographical realms, the Afrotropical, the Palearctic, and the Oriental regions. This pivotal geographical location has made the Arabian Peninsula harbor elements of all zoogeographic regions with a notable influence of the Afrotropical species documented for the southwestern mountains of the Arabian Peninsula, Yemen, the Dhofar Governorate, and Jabal Al Akhdar in Oman (e.g. Guichard 1980; Larsen and Larsen 1980; Larsen 1984; Collingwood 1985; Cowie 1989; Collingwood and Agosti 1996; Pesenko and Pauly 2009; Sharaf and Aldawood 2011, 2012, 2019; Sharaf et al. 2012a, b, c; El-Hawagry et al. 2013, 2016a, b, 2017; Abdel-Dayem et al. 2019).

Numerous studies have considered that the southwestern Arabian Peninsula, which includes the Al Sarawat Mountain and the Asir Mountains (KSA) and Yemen, with clear Afrotropical affinities (e.g. Larsen and Larsen 1980; Collingwood 1985; Collingwood and Agosti 1996; Taiti et al. 2000; Hausmann 2009; Pesenko and Pauly 2009; Sharaf and Aldawood 2011, 2012, 2019; Sharaf et al. 2012a, b, c; El-Hawagry et al. 2013, 2016a, b, 2017; Hájek and Reiter 2014; Ball et al. 2015; Abdel-Dayem et al. 2019). Some studies conjoin the Dhofar Governorate, Jebel Akhdar (Oman) and the Hajar Mountains that extend between Oman and the UAE to the Arabian areas of Afrotropical elements but with relatively lesser degrees of Afrotropical affinities (Larsen 1984; Cowie 1989; Delany 1989; Penati and Vienna 2006).

Aenictus

A single species, Aenictus arabicus, is present. This ant is a member of the Aenictus wroughtonii group. There is information about diagnostic characters on the species page and the species group page, plus a Key to the Aenictus wroughtonii species group and a shorter key, with the species that most resemble A. arabicus, in the paper cited just below.

Sharaf, Aldawood, and El-Hawagry (2012) - Most Aenictus species are tropical (Brown 2000) and forage in soil and leaf litter. Aenictus are all believed to hunt other ants and termites (Gotwald 1995, Rosciszewski and Maschwitz 1994). Ten species of Aenictus have been reported from the Palaearctic, nine of which are distributed in the Southwestern part of the region, from Morocco in the west to Afghanistan in the east (Aktaç et al. 2004). Many of the Southeast Asian species forage on the ground, with a few utilizing trees (e.g., Hirosawa et al. 2000).

The presence of an Aenictus species in the Southwestern part of Saudi Arabia is not surprising as the area is regarded as Afrotropical. There are likely more Afrotropical ants awaiting discovery in the area.

Anochetus

Saudi Arabia Anochetus species

Key to Arabian Anochetus.

Aphaenogaster

Saudi Arabia Aphaenogaster species

Key to Arabian Aphaenogaster.

Brachymyrmex

Sharaf et al. (2016) reported on the discovery of the introduced Brachymyrmex cordemoyi in Saudi Arabia:

This species was found nesting in soil at the base of a date palm tree (Phoenix dactylifera L.) in King Saud University campus, Riyadh. Specimens were collected by sifting the soil which was a mixture of sandy clay, with much decaying organic material. Workers were found about 8 cm deep in the soil. Other ant species collected with B. cordemoyi included: Solenopsis saudiensis, Nylanderia jaegerskioeldi Tapinoma simrothi and Cardiocondyla mauritanica.

Brachyponera

The only species, Brachyponera sennaarensis, is introduced. The biology section of the species page provides information about this species in the Arabian Peninsula.

Camponotus

Saudi Arabian Camponotus species

There is no key for this set of Camponotus species, but the following include species that occur in the region:

Cardiocondyla

Saudi Arabia Cardiocondyla species

The species can all be identified using the Key to Holartic Cardiocondyla.

Carebara

Saudi Arabia Carebara species

The identification section of the species pages of the two known species, Carebara arabica and Carebara fayrouzae, has a couplet that can be used to distinguished these ants from one another.

Cataglyphis

List of Saudi Arabian Cataglyphis species.

More than 20 species of this taxonomically difficult genus have been recorded from the region. There is no key available.

Crematogaster

Saudi Arabia Crematogaster species

Crematogaster inermis is widespread in the Mediterranean and Middle East. Despite there being one record from the Arabian Peninsula (from Yemen), it seems likely future sampling will reveal C. inermis is more widespread in the region.

Key to Arabian Crematogaster

Sharaf et al. (2019), the Crematogaster of the Arabian Peninsula - There are numerous, scattered, records of Crematogaster on the Arabian Peninsula. Prior to this study, the total number of species was 15 (plus one subspecies), recorded from the Kingdom of Saudi Arabia (KSA) (Collingwood 1985; Collingwood and Agosti 1996), the United Arab Emirates (UAE) (Collingwood and Agosti 1996; Collingwood et al. 2011), the Sultanate of Oman (Collingwood 1985; 1988; Collingwood and Agosti 1996; Sharaf et al. 2018), Yemen (Collingwood and van Harten 1994; 2001; 2005), and Kuwait (Collingwood and Agosti 1996). However, there are no records known from Bahrain, nor the Socotra Archipelago.

The taxonomy of Arabian Crematogaster is even more challenging than in other parts of the world due to the geographic location of the Arabian Peninsula, which connects sub- Saharan Africa or the Afrotropical region with the Mediterranean/Middle East or Palaearctic region (Kreft and Jetz 2010). As a consequence, the Arabian Peninsula shares biogeographical affinities with both, the Afrotropical and Palaearctic regions, however, no modern revisions of Crematogaster exist for these regions around the Arabian Peninsula. While there are some treatments covering particular countries or smaller areas in Europe or the northern Mediterranean, these either just describe new taxa or provide identification resources without revising the genus (Collingwood 1978, Agosti and Collingwood 1987, Cagniant 2005, Seifert 2007, Karaman 2008). In addition, many Crematogaster species have large female reproductives and good dispersal abilities leading to often vast distribution ranges. Thus, to be certain about the identity of any Arabian Crematogaster material it would require examining and comparing hundreds of Afrotropical and Palaearctic type specimens from numerous natural history collections.

As can be seen from the species accounts presented, the taxonomic histories of many species treated herein are complex and problematic. Many species have had numerous status changes and a changing number of infraspecific taxa. In some cases, it is likely that the species listed here will turn out to be senior or junior synonym of another taxon, and it is also very probable that some or many of the infraspecific taxa deserve to be treated as “good” species. As a consequence, except for the few species endemic to the Arabian Peninsula, for most others we suggest caution. Our review of species is based on literature records, material examined by the first author, and Arabian material examined in some European collections. We have pointed out which species we consider well identifiable and which ones are difficult. Overall, we consider previous identifications, as well as ours, as temporary. This study is meant as a first step stone towards a more comprehensive revision of the Arabian Crematogaster fauna. Since comprehensive taxonomic revisions of the genus are not to be expected from neither the Palaearctic nor the Afrotropical regions any time soon, the most sensible solution for the study of Arabian Crematogaster is to visit additional European collections and compare our material with as many types as possible in order to verify or improve the identifications of our material.

Notwithstanding the taxonomic problems lined out above, the treated fauna of Crematogaster exemplifies very well that the Arabian Peninsula shares substantial faunal elements with the Palaearctic (mostly Mediterranean species) and the Afrotropics, with a minority of species currently considered as Arabian endemics. At present, we recognize eight Afrotropical, seven Palaearctic, and two Arabian species, which we think fits fairly well with the biogeography of the Arabian Peninsula. However, this assessment might change with further studies and comparisons with types. We suspect that in some cases it might turn out that our material is not conspecific with any of the previously identified species and might represent another undescribed endemic, but this requires further taxonomic work.

The ant genus Crematogaster is one of the most abundant myrmicine genera in the Arabian Peninsula, especially in the Asir mountains, Yemen, and Oman, particularly in areas with open forests and woodlands of Acacia (Martius, 1829) (Fabaceae) and Juniperus L. (Cupressaceae) trees. The close ecological association between ants and acacia trees has been documented by several authors (e.g., Hölldobler and Wilson 1990; Isbell et al. 2013; Madden and Young 1992; Palmer and Brody 2013; Young et al. 1997). Crematogaster mimosae is known to have mutualistic relationships with other ants in East Africa (Boyle et al. 2017; Palmer and Brody 2013) and we anticipate similar associations to be found in the vast areas of Acacia forests of the southwestern part of the Arabian Peninsula.

Although at present only 17 species of Crematogaster are known from the Arabian Peninsula, further targeted collecting may yield both additional species records and more new species. For example, no Crematogaster have been collected from Bahrain but it is very unlikely that the genus is absent from the country. We are sure that the current absence of Crematogaster records from Bahrain is due to the lack of any national myrmecological studies. The identification key to the Arabian Crematogaster presented herein serves as a foundation for further faunistic studies and taxonomic revisions of the genus.

Cryptopone

Cryptopone ochracea

Dorylus

Dorylus fulvus

Emeryopone

Emeryopone loebli

Hypoponera

Saudi Arabia Hypoponera species

Lepisiota

Saudi Arabia Lepisiota species

Key to Arabian Lepisiota

Sharaf, Mohamed, et al. (2020), referring to the Arabian Peninsula - With 135 described species and subspecies, the ant genus Lepisiota is one of the most diverse genera of the subfamily Formicinae (Bolton 2020). Species occur in the grasslands, savannahs, and woodlands of the Afrotropical, Indomalayan, and Palearctic regions (Brown 2000; Hita Garcia et al. 2013). They may nest in the ground, under stones, or in rotten wood. Numerous Lepisota species attend aphids and coccids (Bolton 1973; Hita Garcia et al. 2013). The genus is diagnosed in the worker caste by the following character states (Bolton 1994): antennae 11-segmented; eyes well-developed, ocelli frequently present but sometimes reduced; propodeum armed with a pair of spines, teeth, or tubercles; petiole a scale-like with the dorsal margin bispinose, bidentate or emarginated; acidopore well-developed.

The taxonomic status of the genus is dreadful. Most contributions are restricted to few treatments including to a limited number of papers including faunal lists, descriptions of new species or taxonomic keys for some regions and countries, such as for the Arabian Peninsula (Collingwood and Agosti 1996; Sharaf et al. 2016), Armenia (Arakelian 1994), the Balkans (Agosti and Collingwood 1987), Bulgaria (Atanassov and Dlussky 1992), China (Wu and Wang 1995; Zhou 2001), Egypt (Finzi 1936), Europe and Algeria (André 1882), India, Sri Lanka and Burma (Bingham 1903), Kingdom of Saudi Arabia (KSA) (Collingwood 1985), and Turkestan (Kuznetsov-Ugamsky 1929).

The Lepisiota fauna of Oman is poorly known due to a lack of appropriate specialized research, and the few available records are scattered through the literature or have been gleaned from few field surveys only accidentally or incidentally. Lepisiota arenaria and Lepisiota spinisquama were the first species to be recorded from Oman (Collingwood 1985). However, L. arenaria is now excluded from the fauna of the Arabian Peninsula due to misidentification. In their treatment of the ant fauna of the Arabian Peninsula, Collingwood and Agosti (1996) reported 20 species from the region, with ten from Oman, including a description of a new species Lepisiota dhofara from the Dhofar Governorate. Sharaf et al. (2016) described Lepisiota omanensis from Oman and the United Arab Emirates (UAE) and presented a key to the Arabian Lepisiota species.

Our new collections and previous literature records (Collingwood 1985; Collingwood and Agosti 1996; Collingwood et al. 2011) indicate that the Lepisiota fauna of the Arabian Peninsula includes 21 species, which is clearly represented by taxa of the Afrotropical and the Palearctic regions (Table 1, Fig. 8). About 53% of these species have strong affinities with the Afrotropical Region (11 species), followed by the Palearctic elements (including western and eastern boundaries of the Palearctic region) with about 48% (10 species). This Afrotropical preponderance has been previously recognized by numerous studies (e.g. Guichard 1980; Larsen and Larsen 1980; Larsen 1984; Collingwood 1985; Cowie 1989; Waterston and Pittaway 1991; Schneider and Krupp 1993; Collingwood and Agosti 1996; Taiti et al. 2000; Hausmann 2009; Pesenko and Pauly 2009; Sharaf and Aldawood 2011, 2012, 2019; Neubert and van Damme 2012; Sharaf et al. 2012a, b, c; El-Hawagry et al. 2013, 2016a, b, 2017; Hájek and Reiter 2014; Ball et al. 2015; Abdel-Dayem et al. 2019). The close Afrotropical affinity of the taxa mentioned in the above studies supports the direct linkage of Afrotropical lineages with the Arabian Peninsula. However, the Oriental influence is absent but it is anticipated some taxa from the region might be exist with extensive collecting. The minor Oriental influence is documented by some studies as Larsen (1984) on the Arabian fauna of the butterflies (Larsen 1984), Penati and Vienna (2006) on the Arabian Histeridae, and Abdel-Dayem et al. (2019) on the Carabidae of Shada Al-A’Ala Nature Reserve, Southwestern KSA. Obviously much more collecting efforts must be done to allow an in-depth zoogeographical treatment for confirming speculation.

These distributional patterns indicate that zoogeographically the area of the Arabian Peninsula is not a homogeneous unit. Our analysis of Lepisiota zoogeographic affinities generally supports Larsen and Larsen (1980), Larsen (1984), Abdel-Dayem et al. (2019), Cowie (1989), Penati and Vienna (2006), Rueda et al. (2013), Sharaf et al. (2014), Ficetola et al. (2017), Delany (1989), El-Hawagry et al. (2019) arguments that a major zoogeographic discontinuity exists within the region. Despite this, as mentioned above about 38% (8 out of 21 spp.) of the species appear to be endemic to the region.

Our available data of the distribution of the Arabian fauna of Lepisiota clearly show a confined distribution of all the Afrotropical species and the endemic species to the southern Arabian Peninsula, whereas those Afrotropical species are not represented in the arid regions of the Arabian deserts and obviously are replaced by taxa of the Palearctic region. These data fully coincide with the findings of several studies that draw the boundaries between the Afrotropical and the Palearctic regions of the Arabian Peninsula as a line connecting the mountainous coastal strip that is parallel to the Red Sea in the western Arabian Peninsula starting from Taif and southwards to Yemen, parts of Oman (Dhofar, Jebel Akhdar) and the UAE) (the Hajar Mountains) (Fig. 9) (Larsen 1984; Cowie 1989; Delany 1989; Penati and Vienna 2006).

The distribution pattern of the Arabian Lepisiota is restricted to two major regions of the Arabian Peninsula: the forests of the southwestern mountains and the vast surrounding deserts. The distribution of the Afrotropical species is obviously confined to forests of the southern Arabian Peninsula of the KSA, Yemen, and Oman, whereas the Palearctic species are mainly represented outside this geographic range and precisely correlated to the desert ecosystems of the Arabian Peninsula. Hence, while the Afrotropical influence decreases towards the north and east, the Palearctic influence increases correspondingly. This geographic correlation is likely related to habitat availability, soil nature, and vegetation cover in the two ecosystems. Environmental impact obviously favors the spread and maintenance of a species over another and can result in a vast distribution (Larsen 1984; Cowie 1989).

The Arabian Lepisiota fauna, however, includes a noteworthy proportion of apparently endemic species (38.10%) represented by eight species, Lepisiota arabica, Lepisiota dammama, Lepisiota dhofara, Lepisiota elbazi, Lepisiota elegantissima, Lepisiota harteni, Lepisiota omanensis, and Lepisiota riyadha. This high degree of endemism for the Arabian Peninsula is documented for several groups of animals including amphibians (Arnold 1980), reptiles (Šmíd 2010; Melnikov and Pierson 2012), birds (Ball et al. 2015), arthropods of different groups including Isopoda (Taiti et al. 2000), Lepidoptera (Larsen and Larsen 1980; Hausmann 2009), Isoptera (Cowie 1989), Odonata (Waterston and Pittaway 1991; Schneider and Krupp 1993), Coleoptera (Hájek and Reiter 2014), and Hymenoptera (Collingwood 1985; Collingwood and Agosti 1996; Pesenko and Pauly 2009; Sharaf and Aldawood 2019).

Our analysis of species endemism is distinctly higher than the degree of endemism of numerous animal groups which include the works of Cowie (1989) for the Arabian Isoptera (24%), Abdel-Dayem et al. (2018) for the Carabidae of Garf Raydah (southern KSA) (19.3%), Larsen (1984) for the Rhopalocera (15.5%), Collingwood (1985) for the Formicidae of the KSA (11%), Collingwood and Agosti (1996) for the Formicidae of the Arabian Peninsula (25%), Abdel-Dayem et al. (2019) for the Carabidae of Shada Al-A’Ala Nature Reserve (KSA) (5.3%), Abdel-Dayem et al. (2017) for the Carabidae of the beetle fauna of Rawdhat Khorim National Park (KSA) (6.0 %), Penati and Vienna (2006) for the Histeridae (7.5%).

The ant genus Lepisiota along with two other genera (Camponotus and Cataglyphis') are the most diverse and abundant genera of the subfamily Formicine both in Oman and in the entire Arabian Peninsula (Collingwood 1985; Collingwood and Agosti 1996; Sharaf et al. 2018). They are represented in Oman by the following number of species; Camponotus (18), Cataglyphis (15) and Lepisiota (15). In the Arabian Peninsula the number is as follows; Camponotus (25), Cataglyphis (28) and Lepisiota (26). An inventory in the southwestern mountains of the KSA using several collecting techniques (Pitfall, Malaise, and light traps) revealed a similar pattern of abundance and diversity of the three genera (Sharaf et al. unpublished data).

Among this remarkable abundance and diversity of many species of Lepisiota, however, there are some rare species known only from a few specimens, e.g. Lepisiota arabica (5), Lepisiota dhofara (1), Lepisiota dammama (5), Lepisiota elbazi sp. nov. (2), and Lepisiota omanensis (5). Not only are there morphological similarities between [[Lepisiota elbazi and its congener [[Lepisiota arabica but they have similar habitat preferences with both species appearing to prefer the mountainous territories of the Dhofar Governorate for L. elbazi and the southwestern mountains of the KSA for L. arabica.

The taxonomic keys for the Lepisiota fauna of the KSA (Collingwood 1985) and the Arabian Peninsula (Collingwood and Agosti 1996) have some degree of apparent ambiguity in some of their parts, which results in the difficulty of species identification. Therefore, interested workers in the region must be careful when dealing with these two keys.

Leptogenys

Saudi Arabia Leptogenys species

The identification section of the Leptogenys polaszeki species page provides the details needed to distinguish the two species that occurr in the region.

Lioponera

Lioponera longitarsus

Melissotarsus

Melissotarsus emeryi

Meranoplus

Meranoplus pulcher

Sharaf and Aldawood (2019) - The first report of the genus Meranoplus from the Arabian Peninsula (Sharaf, Al Dhafer & Aldawood, 2014) described a new species, M. pulcher of the M. magretii-group based on the worker caste, from the southwestern mountains of the KSA. Recently, the queen caste of M. pulcher was discovered for the first time based on a single specimen collected from the type locality by pitfall traps (Sharaf & Aldawood, 2017). The genus was then recorded for the first time from Oman (Meranoplus mosalahi), based on recently collected ant specimens from the Dhofar Governorate. These specimens are described here as a new species.

Mesoponera

Mesoponera ambigua

Messor

Saudi Arabia Messor species

Monomorium

Saudi Arabia Monomorium species

The key to Arabian Monomorium monomorium group species can be used to identify the species of this species group, which make up about a quarter of the Monomorium species occurring in the region.

Nesomyrmex

Nesomyrmex angulatus

Sharaf, Monks, et al. (2020) - The myrmicine ant genus Nesomyrmex was originally described by Wheeler (1910) with the type species Nesomyrmex clavipilis, by monotypy, and later was treated by Emery (1915) as a subgenus or junior synonym of the genus Leptothorax (e.g. Wheeler 1922; Kempf 1959; Bolton 1982) and later it was revived from the mentioned synonymy and elevated to the generic level by Bolton (2003) in the tribe Crematogastrini.

Currently, the genus includes 81 described species, one valid subspecies, Nesomyrmex angulatus lybica, and two extinct species, Nesomyrmex caritatis (De Andrade et al. 1999) and Nesomyrmex dominicanus (De Andrade et al. 1999), from the Dominican Amber (De Andrade et al. 1999; Bolton 2020). The genus is one of the taxonomically best studied genera in the subfamily Myrmicinae, with numerous published contributions on the fauna of most zoogeographical regions including the Afrotropical (Bolton 1982; Mbanyana and Robertson 2008; Hita Garcia et al. 2017), the Malagasy (Wheeler 1922; Csősz and Fisher 2015, 2016a, 2016b, 2016c), the Nearctic (Guénard and Economo 2016), the Neotropical (Kempf 1959, 1972; Brandão 1991), and the Palearctic (Collingwood 1985; Collingwood and Agosti 1996; Sharaf et al. 2017). A detailed taxonomic history of the genus is given by Hita Garcia et al. (2017). The bionomics and sociobiology of the genus are still not fully understood, but most species are generalised foragers (Brown 2000) preferring dry habitats, and build nests directly in the soil, under stones or in rotten branches (Collingwood 1985; Collingwood and Agosti 1996), while a few are tropical dry forest and rainforest dwellers (Kempf 1959; Hita Garcia et al. 2017; Castro et al. 2018).

Member species can be diagnosed by the combination of the following characters in the worker caste (Fisher and Bolton 2016): antennae with 11 or 12 segments, terminating in a three-segmented club; masticatory margin of mandibles armed with 3–5 teeth; posterior clypeal portion broadly inserted between frontal lobes and anterior margin without paired median setae; eyes well developed. The closest relative myrmicine genus to Nesomyrmex is the Temnothorax, from which it can be separated by the presence of an anterior clypeal apron that fits tightly over the dorsal surface of mandibles when seen in profile.

The previous records of the Nesomyrmex fauna of the Arabian Peninsula are scattered in the literature under the genus Leptothorax. The first record was presented by Collingwood (1985) for the species N. angulatus from the south-western mountains of the Kingdom of Saudi Arabia (KSA). A faunal treatment of the Arabian Formicidae (Collingwood and Agosti 1996) reported two species, N. angulatus from the KSA and Yemen, and Nesomyrmex humerosus from Yemen. Recently, Sharaf et al. (2017) fully revised and illustrated the Arabian Nesomyrmex, recognising three species and describing N. zaheri from Yemen based on the worker caste.

Oxyopomyrmex

Oxyopomyrmex nitidior

Key to Oxyopomyrmex workers

Parasyscia

Saudi Arabia Parasyscia species

The identification section of the species pages of the two known species, Parasyscia rifati and Parasyscia wittmeri, has a couplet that can be used to distinguished these ants from one another.

Pheidole

Saudi Arabia Pheidole species

Plagiolepis

Saudi Arabia Plagiolepis species

Key to Arabian Plagiolepis Species

Platythyrea

Platythyrea modesta

Polyrhachis

Saudi Arabia Polyrhachis species

There are two species present: Polyrhachis lacteipennis and Polyrhachis viscosa. They can be distinguished by comparing specimens collected from the region to images on the two species pages.

Solenopsis

Saudi Arabia Solenopsis species

Key to Arabian Solenopsis

Strumigenys

Saudi Arabia Strumigenys species

The two species that occur in the region, Strumigenys arnoldi and Strumigenys membranifera, are in this key: Key to Afrotropical Strumigenys.

Syllophopsis

Saudi Arabia Syllophopsis species

The identification section of the species pages of the two known species, Syllophopsis kondratieffi and Syllophopsis saudiensis, has a couplet that can be used to distinguished these ants from one another.

Tapinolepis

Saudi Arabia Tapinolepis species

Tapinoma

Saudi Arabia Tapinoma species

Technomyrmex

Saudi Arabia Technomyrmex species

Key to Arabian Technomyrmex

Sharaf et al. (2018) - The first treatment of the ants of the Kingdom of Saudi Arabia (KSA) (Collingwood 1985) reported two species, Technomyrmex albipes from the Eastern Region, and Technomyrmex setosus from the southwestern Asir Mountains. In addition, this author mentioned two additional putative species designated as sp. A. and sp. B. and indicating that these taxa may represent undescribed species. In their work on the ant fauna of the Arabian Peninsula, Collingwood and Agosti (1996) briefly treated and keyed the Arabian Technomyrmex species and recorded T. albipes and T. setosus from Yemen. Subsequently, two new species were added to the Arabian Peninsula, Technomyrmex briani and Technomyrmex montaseri from the KSA and Oman, respectively (Sharaf 2009, Sharaf et al. 2011). A key to the Arabian species was included in the latter work. The faunal list of Al Bahah Province (El-Hawagry et al. 2013) recorded T. briani and T. setosus from various localities in the Al Sarawat Mountains of KSA.

Recent collecting efforts, especially in the southwestern Mountains of KSA by the senior author and the entomology team of King Saud University Museum of Arthropods (KSMA) have resulted in new material for study. Also, several years of field surveys (2009-2017) throughout KSA using different collecting methods (e.g. hand collecting, pitfall traps, beating sheets, light traps, etc.), have added material for study, and importantly new information on the distribution of this genus. The study of this new material has allowed us to provide this updated synopsis of the genus for the Arabian Peninsula, providing identification, distribution, and habitat information.