Polyrhachis lacteipennis

This species nests inside the trunks of date palm trees. Several additional workers were found in leaf litter under date palm trees where the soil was loose and dry (Sharaf et al., 2018). Pashaei Rad et al. (2018) found this species in Iran in a very low rainfall area.

Identification
Workers of Polyrhachis lacteipennis vary from 4.5-7.0 mm in body length. They are black in colour with the head and thorax finely punctured and granulate. Pubescence is almost entirely absent except for a few scattered erect hairs on the front of the head and on the apical segments of the gaster. Head is broadly oval; clypeus has a distinct medial vertical carina and is briefly lobed; antennal carinae wide apart and not divergent. They have three pairs of spines: pronotal spines are very short, thick and directed obliquely outwards; propodeal (or metanotal) spines are erect and divergent with the tip slightly bent outwards; two large petiolar spines curved to the shape of the gaster on the upper lateral angles with two obtuse or very small teeth between them. Gaster is short, opaque and globose (modified from Bingham 1903).

Distribution based on Regional Taxon Lists
Afrotropical Region: Saudi Arabia, United Arab Emirates. Oriental Region: India, Nepal. Palaearctic Region: Afghanistan, Iran, Israel, Oman, Turkmenistan.

Biology
These ants construct carton nests at the base of trees, by cementing twigs with their salivary exudates. They are one of the most commonly encountered ants in the urban regions of South India (Narendra & Kumar 2006).



Nomenclature

 *  lacteipennis. Polyrhachis lacteipennis Smith, F. 1858b: 60, pl. 4, fig. 40 (q.) INDIA. Combination in P. (Myrmhopla): Emery, 1925b: 195. Senior synonym of simplex (and its junior synonym spiniger): Bolton, 1974b: 177. Current subspecies: nominal plus obsoleta.
 * simplex. Polyrhachis simplex Mayr, 1862: 682 (q.) INDIA. Wheeler, G.C. & Wheeler, J. 1970: 649 (l.); Imai, Baroni Urbani, et al. 1984: 9 (k.). Combination in P. (Myrmhopla): Emery, 1925b: 196. Junior synonym of lacteipennis: Bolton, 1974b: 177. See also: Bingham, 1903: 394; Ofer, 1970: 49.

Taxonomic Notes
Pashaei Rad et al. (2018): Dietrich (2004) separated specimens from Israel, Jordan and Yemen as a new species, Polyrhachis palaearctica. Antweb do not have photographic images of the type but Dietrich gave SEM images of the lateral and dorsal alitrunk of the worker and the dorsal alitrunk of the queen. The worker appears to be a close fit to those from Israel and Iran held by B.T. Dietrich, however, mentioned P. lacteipennis only vaguely and did not sight the type queen or, apparently, the type of what he refers to as “Polyrhachis simplex”, which also is not on Antweb. The SEM image of the P. palaearctica queen is a near exact match for the P. lacteipennis queen, CASENT0903386. He separated Polyrhachis grisescens as a separate species but the type images (CASENT0905639) also are little or no different from the fresh specimens from Israel and Iran. So we leave our findings as P. lacteipennis.