Tetramorium squaminode Santschi, 1911

Sharaf, Mostafa R., Al Dhafer, Hathal M. & Aldawood, Abdulrahman S., 2015, The Tetramoriumsquaminode species group (Hymenoptera, Formicidae) in the Arabian Peninsula, with a new record from the Kingdom of Saudi Arabia and keys to Arabian species, ZooKeys 502, pp. 99-115 : 103-105

Taxon classification Animalia Hymenoptera Formicidae

Tetramorium squaminode Santschi, 1911

Tetramorium squaminode Santschi, 1911: 356, fig. (w) Tanzania.

Tetramorium squaminode Santschi 1914: 102 (q.m.). See also: Bolton 1980: 260.

Diagnosis.

Worker (Figs 7-9). Head in full-face view distinctly longer than broad with feebly convex sides and nearly straight posterior margin; anterior clypeal margin superficially concave medially; frontal carinae strongly divergent posteriorly, directed towards posterior corners of head; antennal scrobes well developed; eyes relatively large (OI 22-29) situated on midlength of head, with 13 ommatidia in longest row. Mesosoma with rounded pronotal corners when seen from above; in profile metanotal groove feebly impressed or absent; propodeal spines long and sharp; transverse dorsal crest of petiole scale thin and sharp, knife-edged. (DPeI 135-200); in larger specimens petiole dorsum weakly but distinctly emarginate in dorsocaudal view; postpetiole in profile rounded from above; in dorsal view postpetiole hexagonal and much broader than long (DPpI 159-233). Sculpture. Cephalic dorsum sharply and irregularly longitudinally rugulose, sculpture running broken from clypeus to posterior margin of head, area in front of eyes strongly reticulate-rugose, lateral sides of head similar but less strongly sculptured; mandibles faintly but distinctly longitudinally rugulose; clypeus with strong median carinae and two pairs of weaker lateral carinae; mandibles faintly but distinctly longitudinally striated; mesosomal dorsum coarsely irregularly reticulate-rugose; area between propodeal spines when seen from above with three transverse carinae; petiole, postpetiole and gaster dorsum more or less smooth and shining, with very faint superficial sculpture. Pilosity. Frontal carinae with seven pairs of relatively longer hairs straddling the entire line; posterior corners of head with a single pair of characteristically longer hairs compared to rest of cephalic pilosity which is much shorter; mesosomal pilosity relatively less dense and long, some hairs apically clubbed; petiole and postpetiole with abundant apically clubbed long hairs; legs and antennae with appressed hairs. Colour. Cephalic dorsum and gaster dark brown, head sides, mesosoma, petiole and postpetiole yellowish brown.

Measurements.

Worker. TL 2.70-3.35; HL 0.70-0.75; HW 0.62-0.72; SL 0.42-0.57; EL 0.15-0.20; PW 0.47-0.57; WL 0.75-0.90; PSL 0.15-0.25; PTL 0.15-0.20; PTH 0.27-0.35; PTW 0.25-0.30; PPL 0.15-0.22; PPH 0.22-0.27; PPW 0.32-0.45; CI 84-97; SI 60-81; OI 22-29; DMI 55-67; PSLI 24-35; PeNI 29-60; LPeI 50-67; DPeI 135-200; PpNI 61-90; LPpI 63-100; DPpI 159-233; PPI 117-156 (n=12).

Queen (Figs 10-12). Head. Head clearly longer than broad, narrower anteriorly than posteriorly, with straight posterior margin; median portion of anterior clypeal margin feebly concave; eyes situated nearly at midlength of head; eyes large (OI 28-29) with 16 ommatidia in longest row; antennae when laid back from their insertions fail to reach posterior margin of head. Mesosoma. Propodeal spines long thick and sharp; petiole, postpetiole and gaster as in worker caste.

Colour.

Head, mesosomal dorsum, petiole and postpetiole dark brown or blackish brown, gaster dark blackish brown to black, antennae and legs yellowish. Sculpture. As in worker except mesosomal dorsum longitudinally rugose. Pilosity. Pilosity dense over entire body with apically clubbed hairs which are more abundant on postpetiole and rare on gaster; frontal carinae with five pairs of distinctly longer hairs straddling entire length, corners of posterior margin of head with a single pair of longer hairs.

Measurements.

Queen. TL 3.65-3.75; HL 0.85; HW 0.75-0.80; SL 0.55-0.57; EL 0.22; PW 0.67-0.72; WL 1.12-1.25; PSL 0.20-0.25; PTL 0.20-0.22; PTH 0.40-0.42; PTW 0.35-0.37; PPL 0.20-0.22; PPH 0.32-0.35; PPW 0.45-0.47; CI 88-94; SI 69-76; OI 28-29; DMI 58-60; PSLI 24-29; PeNI 49-55; LPeI 48-55; DPeI 168-175; PpNI 65-67; LPpI 63; DPpI 205-235; PPI 122-134 (n=2).

Materials examined.

3 workers, 1 queen, Saudi Arabia, Asir, Abha, Raydah, 18°12.315'N, 42°24.607'E, 2761 m, 26.vii.2014, (Pitfall trap) (Al Dhafer et al. Leg.); 2 workers Saudi Arabia, Asir, Abha, Raydah, 18°12.095'N, 42°24.536'E, 2578 m; 3 workers Saudi Arabia, Asir, Abha, Raydah, 18°12.265'N, 42°24.744'E, 2820 m; 1 worker Saudi Arabia, Asir, Abha, Raydah, 18°11.695'N, 42°23.818'E, 1897 m (all in KSMA) (Al Dhafer et al. Leg.); 1 worker in NHMB; 1 worker (casent0914585) and 1 queen (casent0914584) in CASC (Al Dhafer et al. Leg.).

Habitat.

Tetramorium squaminode was collected from Raydah Protectorate which includes one of the last remnants of dense juniper forest found on the KSA. The vegetation shows distinct altitudinal zonation, although there are variations within zones. The locality (Fig. 13) has a substantial high diversity of wild plants including: Juniperus procera Hochst. ex Endlicher ( Cupressaceae ), Olea europaea ssp. africana (Mill.) P. Green. ( Oleaceae ), Maerua crassifolia (Capparceae), Panicum turgidum ( Poaceae ), Lycium shawii roem ( Solanaceae ), Haloxylon salicornicum ( Chenopodiaceae ), Aloe officinalis Forssk. ( Xanthorrhoeaceae ), Ziziphus spina-christi ( Rhamnaceae ), Opuntia ficus-indica (L.) Mill. ( Cactaceae ), Coffea arabica ( Rubiaceae ) and Acacia spp. ( Mimosaceae ).