Notes on the ant genus Cataglyphis Foerster, 1850 (Hymenoptera, Formicidae) in the Arabian Peninsula with description of a new species and a key to species of the C. pallida-group

Abstract Cataglyphis fisheri sp. n. is described and illustrated from the United Arab Emirates, Oman and Kingdom of Saudi Arabia based on the worker caste. It belongs to the Cataglyphis pallida-group which is recorded for the first time from the Arabian Peninsula. Cataglyphis fisheri sp. n. is similar to Cataglyphis pallida Mayr, 1877 from Kazakhstan. Differential diagnosis between these two species is given and a key to the species of the Cataglyphis pallida-group is presented. Cataglyphis laylae Collingwood, 2011 is treated as a junior synonym of Cataglyphis saharae Santschi, 1929. Cataglyphis flavobrunnea Collingwood & Agosti, 1996 is redescribed and a lectotype for this species is designated.


Introduction
The ant genus Cataglyphis Foerster, 1850 currently includes 108 valid species and subspecies (http://www.antwiki.org/, accessed 15 August 2015) distributed in the desert areas of the Palearctic Region ranging from South Palearctic to Ghana, East to North China and India (Brown 2000). Members of the genus are among the commonest ants of the desert ecosystems of the Arabian Peninsula and Central Asia, where they build their crater nests directly in the ground (Brown 2000, Sharaf and Aldawood, unpublished data) and feed on dead insects (Lenoir et al. 2010). Their role in the desert ecosystem is important as they have been reported pollinating flowering plants (Herrera et al. 1984) and contributing to the dispersal of seeds (Hulme 1997;Boulay et al. 2007).
The worldwide revision of the genus by Santschi (1929) is out of date, but a comprehensive reclassification of the genus and its species groups was presented by Agosti in 1990. Many regional faunal treatments are available: Israel (Emery 1925), Iraq (Pisarski 1965), former European U.S.S.R. (Arnol'di and Dlussky 1978), Iberian Peninsula (Collingwood 1978), Kingdom of Saudi Arabia (KSA) (Collingwood 1985), Turkmenistan (Dlussky, Soyunov and Zabelin 1992), Bulgaria (Atanasov and Dlussky 1992), Armenia (Arakelian 1994), Central Europe (Seifert 1996), Portugal (Collingwood and Prince 1998), Asia species key (Radchenko 1998), Northwest China (Chang and He 2002), Egypt (Sharaf 2006), North and Central Europe species key (Seifert 2007) and Morocco (Cagniant 2009). Many Cataglyphis species are polymorphic, dimorphic or have variation in worker size. This makes it necessary to be cautious when making identifications and, even more, so when treating a single worker as representing a new species.
The Arabian species of Cataglyphis were first treated by Collingwood (1985), who recorded 18 species from the KSA describing two new species C. asiriensis and C. minima from the Asir Mountains of southwestern KSA. Subsequently, Collingwood and Agosti (1996) reviewed the genus for the entire Arabian Peninsula providing a key to species. The 26 recorded species included six new species, C. acutinodis, C. flavobrunnea, C. harteni, C. holgerseni, C. opacior and C. shuaibensis. A myrmecofaunal list of the United Arab Emirates (UAE) (Collingwood et al. 2011) reported 20 species and described an additional new species, C. laylae Collingwood for the Peninsula.
In the present paper a new species, C. fisheri, is described from the UAE based on the worker caste. A new lectotype designation for C. flavobrunnea Collingwood & Agosti, 1996 is presented with redescription of the worker caste. Cataglyphis laylae Collingwood, 2011 is shown to be a junior synonym of C. saharae Santschi, 1929.

Measurements and indices
All measurements are in millimeters and follow standard measurements of Agosti (1990).

Measurements Eye length (EL)
Maximum diameter of eye.

Head length (HL)
Length of head proper, excluding mandibles, measured from mid-point of anterior clypeal margin to mid-point of posterior head margin, in full-face view.

Head width (HW)
Maximum width of head in full-face view, measured below eyes. Metanotum height (MH) Maximum distance from line spanned between anteriormost and posteriormost part of mesosoma and lowest part of metanotum, measured at a right angle to this line.

Mesosomal length (ML)
Diagonal length of mesosoma in profile from point at which pronotum meets the cervical shield to posterior base of metapleuron. Median ocellus size (OS) Diameter of the ocelli.

Ocelli distance (OD)
Distance between the two basal ocellus. Propodeum height (PH) Maximum distance from a line spanned between anteriormost and posteriormost part of mesosoma and most raised part of propodeum, measured at a right angle to this line.

Pronotal width (PW)
Maximum width of pronotum measured in dorsal view.

Petiole height (PTH)
Maximum height of petiolar measured in lateral view from highest (median) point of node to ventral outline.

Scape length (SL)
Maximum straight line length of antennal scape excluding basal constriction or neck to condylar bulb.

Total length (TL)
Outstretched body length from mandibular apex to gastral apex.

Funicular index (FI)
Length of first funicular segment × 100/Length of second funicular segment.

Scape index (SI)
SL × 100/HW. In the original description of Cataglyphis flavobrunnea Collingwood and Agosti fixed the holotype from Oman and listed nine paratype specimens from Oman, The KSA, The United Arab Emirates and Yemen. Extensive searches in WMLC and NHMB did not succeed in finding the holotype specimen but nine specimens matching the paratypes data from the KSA were located. As recommended by the International Commission of Zoological Nomenclature, we designate a lecotype in this study to unequivocally ascertain the identity of the species  .

Cataglyphis fisheri
Worker. Head. Head distinctly longer than broad (CI 83-94), with straight posterior and lateral margins; posterior ocelli located at the level of posterior margin of eyes; scapes when laid back from their insertions surpass posterior margin of head by less than ¼ of its length. Mesosoma. Propodeal dorsum in profile distinctly low, nearly at same level as petiolar node. Petiole. Petiole an upright or slightly inclined scale, with the anterior face meeting the posterior face with a narrowly rounded margin angle. Pilosity. Third maxillary palp with erect hairs not longer than 1.5× maximum diameter of third segment; area behind the lateral clypeal margins with dense white pubescence, anterior clypeal margin with abundant long, curved, hairs; mesosomal dorsum with a few scattered hairs, two pairs each on the mesonotum and propodeum, petiole bare, gaster bare except for a few short hairs on apex, posterior margin of head with single pair of erect hairs. Sculpture. Cephalic dorsum faintly sculptured; median cephalic surface in front of ocelli feebly but distinctly longitudinally striated, striae curving outward to lateral margins in front of eyes; mandibles faintly but distinctly longitudinally striated, mesosoma and petiole faintly sculptured, general appearance dull. Colour. Uniform yellow, mandibular teeth brown. Affinities. Cataglyphis fisheri is a member of the C. pallida-group as defined by Agosti (1990), which is recorded here for the first time from the Arabian Peninsula. Although Collingwood and Agosti (1996) reported 265 species or morhospecies from the entire Arabian Peninsula, a large number of ant specimens remained unidentified. Cataglyphis fisheri was among those specimens. The workers cannot be identified from the key to Arabian species compiled by Collingwood and Agosti (1996) because material was not included in the study. However, C. fisheri is similar to the Palearctic species C. pallida Mayr, 1877 described from Kazakhstan. A differential diagnosis of the two species is summarized in Table 1.
In the key to Arabian species (Collingwood and Agosti 1996), C. fisheri will run to couplet 12 that also includes the much larger C. sabulosa Kugler, 1981. Cataglyphis fisheri sp. n. can be readily separated by the upright or slightly inclined petiole with a dorsal rounded node, the lower propodeal profile and the absence of body pubescence whereas C. sabulosa has a squaminode petiole with a convex anterior surface and straight posteriorly, a higher propodeal profile and the body covered with white silvery pubescence. The drawing of C. sabulosa in Collingwood (1985) is incorrect.

1
Colour uniform brown or dark brown; mesosoma massively constructed; in profile propodeal dorsum high, meeting declivity in a distinct obtuse angle (