Syllophopsis dentata

One type series, including the holotype, was found nesting under a rock in a small village 3 km from El-Minyia city (Upper Egypt); there were many Collembola and a single unidentified specimen of the ant genus Pyramica (Trichoscapa) Roger, 1862, living in the same niche. (Sharaf 2013)

Identification
Sharaf (2007) - This new species is a member of the Monomorium fossulatum-group as defined by Bolton (1987) and cannot be identified with any of the Monomorium species in Bolton’s key to the Afrotropical species. S. dentatum appears taxonomically closest to Syllophopsis sersalata, which was described from Rwanda, and Syllophopsis thrascolepta, which was described from Ivory Coast. All three species are uniformly yellow; the promesonotum profile is evenly convex, the propodeum immediately behind the metanotal groove rises to an acute peak then slopes posteriorly to a pair of distinct projecting denticuliform angles at the junction of the dorsum and declivity; the propodeum with two or three pairs of hairs; the scapes and sides of the head behind the eyes have erect to suberect pubescence; sides of pronotum are smooth; and the area between the mesopleuron and metapleuron is faintly cross-ribbed.

S. dentatum may be closer to S. thrascoleptum, but is consistently smaller, TL 1.49-1.63 versus TL 1.9-2.2 mm; has a lower scape index, SI< 100 versus SI 103-110; and M. dentatum also has sculpturation on the mesopleuron, which is smooth in S. thrascoleptum. The latter is known only from a single collection from Ivory Coast, West Africa.

Comparing S. dentatum with S. sersalatum, the scape index is similar but M. dentatum is smaller, TL 1.63 mm or less, versus TL 2.0-2.2 mm; the metanotal groove in S. dentatum is distinctly U-shaped whereas in S. sersalatum it has a sharply defined V-shape; in S. sersalatum the erect hairs on the body are shorter (Bolton 1987).

The Syllophopsis fossulatum-group contains seven species, widely distributed in tropical Africa (Bolton 1987) and two species, S. fossulatum Emery and S. australicum Forel, which are widespread in the Indo-Australian region and on the islands of the Pacific and Indian Oceans (Wilson & Taylor 1967).

Distribution based on Regional Taxon Lists
Palaearctic Region: Egypt.

Biology
Sharaf (2007) - Collected from different localities in Egypt (Damietta, El-Minyia, Qalyubiya and Port Said) and represents the first record of the fossulatum-group from Egypt and the Palaearctic region. It seems likely that M. dentatum has a wide distribution inside Egypt especially in the Nile river valley because specimens collected from Damietta, Abu-Swelem (El-Minyia) and Abuzabal (Qalyubiya) are all rather close to the river with the exception of the single specimen collected from Port Said.

Sharaf and Taylor (2009) - Sharaf (2007) expected M. dentatum would be widely distributed inside Egypt, especially in the Nile river valley, as all the localities, Damietta, Abu-Swelem (El-Minyia) and Abuzabal (Qalyubiya), were close to the river. Recently the senior author collected workers from Um Khnan, a small village near Giza, March 4, 2009, 30.01°N 31.13°E, so confirming the wide distribution along the Nile valley.

Sharaf and Aldawood (2013) -Nesting in or near date palm trees in damp soil.

Castes
Known only from the worker caste.

Nomenclature

 *  dentata. Monomorium dentatum Sharaf, 2007: 94, figs. 1, 2 (w.) EGYPT. Combination in Syllophopsis: Ward et al., 2014: 13.

Worker
[holotype in brackets]. TL 1.49-1.63 [1.63]; HL 0.39-0.43 [0.41]; HW 0.33-0.36 [0.34]; CI 82.9-92.3 [82.9]; SL 0.34-0.35 [0.34]; SI 98.6-101.4 [100]; EL 0.02 [0.028]; PL 0.184-0.210 [0.184]; PW 0.110-0.120 [0.113]; PPL 0.110-0.127 [0.127]; PPW 0.09-0.127 [0.127] (13 specimens measured including the holotype and the same series, Damietta, 20.viii.2003, 31 °26'N, 31 °48'E).

A unicolorous yellow, smooth, shining and slightly hairy ant. Monomorphic with very small size variation within the same nest. Head clearly longer than broad, smooth and shining with abundant, minute and scattered hair pits on the dorsum; sides of head with dense and relatively long yellow hairs. Mandibles armed with 4 teeth, the 3rd and the 4th teeth not close to each other; the whole mandible surface with relatively long and abundant yellow hairs. Frontal carinae very short; the area behind the lateral clypeal margins and adjacent to antennal insertions widely depressed. Antennae 12-segmented with a well defined 3-segmented club; antennal scapes with abundant and relatively long hairs; funiculus with very short and dense hairs; antennal club with very dense pubescence; the terminal funicular segment clearly longer than the two preceding segments together; the 2nd to 8th funicular segments clearly wider than long. Eyes very tiny with one ommatidium. Occiput raised. Pronotum sides smooth; promesonotum in profile with dorsal outline evenly convex; metanotal groove sharply defined as a U-shaped impression; junction of propodeal dorsum and declivity equipped with a pair of minute tubercles or tiny denticles; propodeal spiracles relatively large and round; lower part of mesopleuron faintly but conspicuously punctulate-shagreenate; impression between mesopleuron and metapleuron faintly cross-ribbed. Pronotum with about 9 pairs of relatively long erect hairs; mesonotum with 3 pairs, propodeal dorsum with 2 pairs of hairs. Petiole pedunculate, with a high rounded node and one pair of long hairs; subpetiolar process simply dentiform. Postpetiole as long as broad, with one or two pairs of hairs. Gaster smooth and shining with abundant scattered and relatively long hairs. Dorsal surfaces of head, alitrunk and gaster unsculptured except for scattered hair-pits.

Queen
1 dealated queen, Egypt: Damietta, 13.viii.2008, 31.24°N 31.44°E; (Mostafa R. Sharaf), Egyptian Entomological Society Collection (EESC), Cairo, Egypt. TL 2.60; HL 0.50, HW 0.45, SL 0.35, EL 0.15, PL 0.23, PW 0.15, PPL 0.15, PPW 0.22. Indices: CI 90; SI 78.

Body unicolorous yellow or yellowish brown, legs and antennae yellow, eyes and ocelli brown. Head clearly longer than broad, broader posteriorly than anteriorly. With head in full-face view the sides clearly convex and the occipital margin shallowly concave. Masticatory margins of mandibles with 4 teeth, the apical one being the longer and brown, the second and the third are subequal and brown, the basal one yellow and the shorter; eyes large, oval, with 15 ommatidia in the longest row. Antennae 12-segmented, antennal scapes, when laid straight back from their insertions, failing to reach the occipital margin. Mesosoma narrow, considerably longer than broad; mesonotum higher than pronotum, mesonotum dorsum and sides smooth and shining with abundant sparse hair pits; propodeal spines small but acute. Petiole with a long peduncle and convex and narrow dorsum and with several pairs of long hairs. Postpetiole dorsum clearly convex, broad and with several pairs of long hairs. The ventral dent short and acute. First gastral tergite paler than the rest. Entire body abundantly hairy; all dorsal surfaces of head and body with dense standing long pilosity and sides of head in full-face view with freely projecting long hairs both in front of and behind the eyes. Pilosity of scapes and tibiae elevated, not appressed. Head dorsum punctuate to reticulate punctuate. Area between frontal carinae to the occipital margin faintly longitudinally striate.

Type Material
Holotype. Worker, Egypt, Damietta, 20.viii.2003, 31°26'N, 31°48'E, leg. M. R. Sharaf.- Paratypes: 17 workers, same series as holotype, 13 workers, Abu-Swelem, El-Minyia, 29.vi.2003, 28°06'N, 30°45'E, leg. M. R. Sharaf; 3 workers, Abuzabal, Qalyubiya, 21.vi.2003, 30°03'N, 31°15'E, leg. M. R. Sharaf; 1 worker, Port Said, 26.viii.2003, 31°16'N, 32°18'E, leg. M. R. Sharaf.

The holotype is deposited in the entomological collection of the Egyptian Entomological Society, Cairo (EESC); paratypes are deposited in the entomological collection of the Entomology Department, Faculty of Science, Ain Shams University, Cairo (ASUC) and in the entomological collection of the Ministry of Agriculture, Giza (MAC).

Etymology
The species name is based on the dentate propodeum and was proposed by Cedric A. Collingwood.