The species of the genus Enicospilus Stephens, 1835 in Saudi Arabia are reviewed. Six species have previously been recorded from Saudi Arabia: E. brevicornis (Masi, 1939), E. capensis (Thunberg, 1822), E. nervellator Aubert, 1966, E. perlatus Shestakov, 1926, E. psammus Gauld & Mitchell, 1978 and E. oculator Seyrig, 1935. Five new species are described and illustrated in this paper: Enicospilus 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. Twelve species are newly recorded for the fauna of Saudi Arabia, thus raising the total number to 23 species: E. bicoloratus Cameron, 1912, E. divisus (Seyrig, 1935), E. dubius (Tosquinet, 1896), E. grandiflavus Townes & Townes, 1973, E. odax Gauld & Mitchell, 1978, E. oweni Gauld & Mitchell, 1976, E. pacificus (Holmgren, 1868), E. pallidus (Taschenberg, 1875), E. rundiensis Bischoff, 1915, E. senescens (Tosquinet, 1896), Enicospilus sp. 1 and Enicospilus sp. 2 cf. bicoloratus Cameron, 1912. The unknown male of E. odax is described for the first time. The COI barcodes of 17 specimens were sequenced, compared to the existing data and uploaded to the BOLD Systems database. An illustrated key and an annotated faunistic list of all species of Enicospilus in Saudi Arabia are also provided. Finally, we discuss the biogeographical and ecological significance of the Enicospilus fauna in Saudi Arabia.

Rawdhat Khorim, a densely vegetated alluvial basin supporting a distinctive floral community in the hyper-arid desert of central Saudi Arabia, is one of the most important protected nature sanctuaries of the country. The ant fauna (Formicidae) of Rawdhat Khorim was sampled and 14 species, including one new species were collected using a variety of sampling methods. The new species, Tetramorium saudicum sp. n., a member of the T. caespitum-group, is described based on the worker caste. Cataglyphis viaticoides (André) is recorded for the first time from Saudi Arabia. The information in this paper will allow natural resource managers to establish long-term ecological studies, using sentinel taxa such as ants to evaluate present and future impacts on Rawdhats.

The Farasan Archipelago is a group of small coral islands and islets in the southern Red Sea, offshore of the southwestern Kingdom of Saudi Arabia (KSA). These islands are internationally important as breeding sites for turtles and bird species and regionally for its threatened, rare, and endemic flora and other fauna. The beetles (Coleoptera) of the Archipelago have not been previously surveyed. This study presents the first data on the beetle fauna based on a recent survey of the Farasan Archipelago. In total, 179 beetle species (including three synanthropic species) in 145 genera and 31 coleopteran families were determined. The Carabidae are represented by 31 species, followed by the Tenebrionidae (22 species), Chrysomelidae (17 species), Scarabaeidae (13 species), and Coccinellidae (12 species). The genusLasioceraDejean, 1831 and the speciesAmblystomus villiersanusBruneau de Miré, 1991 (Carabidae) are new for the beetle fauna of the Arabian Peninsula, and eighteen species are new country records for KSA. Sand dune habitats on the islands were inhabited by the greatest number of species in comparison with other habitats. Zoogeographically, the beetle fauna of the Archipelago was dominated by the representatives of the Saharo-Arabian and Afrotropical elements (74 spp., 41.0%). Fourteen species (7.8%) were recognized as cosmopolitan and subcosmopolitan. No species was known to be exclusively endemic to Farasan Archipelago. Eighteen species (10.1%) were endemic to Arabian Peninsula and KSA. Approximately 64.8% (116 spp.) of the archipelago beetle species is found on the KSA mainland and is most closely allied to the south and southwestern KSA regions (sharing 91 spp.). Comparisons of the beetle faunas of the Farasan and Socotra archipelagos indicate that 30 families, 70 genera, and 28 species are shared.

119 named species, belonging to 48 genera are recorded from the Arabian Peninsula. Of these 21 species are described as new to science, being Scoliophthalmus cryptonevriformis, Elachiptera acanthellata, Pselaphia acuticornis, P. albiseta, P. sabroskyi, P. yemenensis, Polyodaspis abhaensis, Calamoncosis sorghivora, Tricimba africana, Aphanotrigonum vanemdeni, Incertella dimorphica, Sabroskyina sinuata, Trachysiphonella dawahi, T. recurva, Eutropha dancei, E. longicornis, Chloropsina enigma, Merochlorops vanharteni, Lagaroceras argillum, Stenophthalmus baderi and S. occidentalis. Seven species are placed in new combination, being Melanochaeta umbrosa (Becker), M. vulgaris (Adams), M. scapularis (Adams), M. atricornis (Adams) and M. flavofrontata (Becker) to Lasiochaeta, Conioscinella amabilis (Becker) to Gaurax and Chlorops lucidifrons Becker to Lasiosina. Lasiosina aurea Dely-Draskovits is placed as a junior synonym of L. lucidifrons (Becker) and Aprometopis sylvestrii Séguy is placed as a junior synonym of Strobliola flavofacies (Becker). Calamoncosis occulta (Becker) is partially re-described. Immature stages are described where available.

The ant genus Trichomyrmex Mayr, 1865 is revised for the Arabian Peninsula based on the worker caste. Nine species are recognized and descriptions of two new species, T. almosayari sp. nov. and T. shakeri sp. nov. from Riyadh Province, Saudi Arabia, are given. For nomenclatural stability, lectotypes for T. abyssinicus (Forel, 1894a), T. lameerei (Forel, 1902) and T. mayri (Forel, 1902) are designated. A key to species and diagnostic characters of the treated species are presented. New country records are presented for T. abyssinicus (Saudi Arabia), T. destructor (Jerdon, 1851) (Saudi Arabia and the United Arab Emirates) and T. mayri (Qatar). New distributional records for T. destructor and T. mayri for Saudi Arabia are also provided. World and regional species distributions are indicated and distributional maps for nine Arabian species are included. Ecological and biological information is given when known.

The dramatic increased rates of uncontrolled urbanisation in various parts of the World have resulted in loss of native species and overall threats to biodiversity. Over the last few decades Saudi Arabia has witnessed a remarkably rapid population growth and unparalleled levels of urbanisation, leading to threats to biodiversity. In this study we focused on arid city (Riyadh, Saudi Arabia) where ant assemblages cross an urban-rural gradient. Ants were collected by pitfall traps from 15 sites along three different urbanisation gradients at 3-monthly intervals throughout 1 year. Ant abundance, species richness, evenness, and α diversity were consistent across the urbanisation gradient. However, significant differences were observed in ant β diversity and assemblage composition between rural and urban, suburban and urban, but not between rural and suburban sites. Eleven ant species were identified as indicator species (IV values between 50.7% and 80.7%). These ant assemblages were influenced by flora, ground cover, soil variables, and urbanisation characteristics. To conclude, we found a significant effect of urbanisation on the β diversity and composition of ant assemblages.