Research Article |
Corresponding author: Mostafa R. Sharaf ( antsharaf@gmail.com ) Academic editor: Brian Lee Fisher
© 2015 Mostafa R. Sharaf, Hathal M. Al Dhafer, Abdulrahman S. Aldawood.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Sharaf MR, Al Dhafer HM, Aldawood AS (2015) The Tetramorium squaminode 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: 99-115. https://doi.org/10.3897/zookeys.502.9011
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The Arabian species of the Tetramorium squaminode-group are treated. Tetramorium squaminode Santschi, 1911 is recorded for the first time from the Kingdom of Saudi Arabia and the Arabian Peninsula. Keys to the two Arabian species of the T. squaminode-group, T. latinode Collingwood & Agosti, 1996 and T. squaminode, based on worker and queen castes, are given and a regional distribution map is provided. Notes on habitats of T. squaminode are presented.
Myrmicinae, Middle East, Palearctic Region, Asir Mountains, taxonomy, keys, squaminode-group
The genus Tetramorium Mayr, 1855 is one of the largest and most species-rich ant genera in the Formicidae with 575 described species (www.antwiki.org) distributed worldwide (
The majority of the Arabian species of the genus Tetramorium can be readily distinguished by the combination of the following characters in the worker caste (
The T. squaminode-group was characterized by
The Tetramorium fauna of the Arabian Peninsula is still relatively poorly known when taken in consideration of the vastness of the peninsula (3,100,000 km2) and many areas are unexplored entomologically. The first contribution to the knowledge of the genus Tetramorium of the region was presented by
In the present study, the species of the T. squaminode-group occurring in the Arabian Peninsula are treated. Two species are known, T. latinode Collingwood & Agosti, 1996 and T. squaminode Santschi, 1911. The latter species is recorded for the first time from the KSA and the entire Arabian Peninsula. Keys to the two Arabian species are provided based on worker and queen castes with notes on habitats of Tetramorium squaminode Santschi.
Study area. The Raydah Protectorate in the mountains of southwestern KSA is one of the smallest areas set aside as a conservation reserve area in 1989 and is located 10 km west of the city of Abha, (18°12'N, 42°24'E). The total area is about 9 km2, but given a drop of 1000 m in 3 km, the estimated total area is closer to 12 km2. The village of Raydah lies at 1600 m just outside the protected area (
(Following
Head length (HL) maximum distance from mid-point of anterior clypeal margin to mid-point of posterior margin of head, measured in full-face view.
Head width (HW) width of head directly behind eyes measured in full-face view.
Scape length (SL) maximum scape length excluding basal condyle and neck.
Eye length (EL) maximum diameter of compound eye measured in oblique lateral view.
Pronotal width (PW) maximum width of pronotum measured in dorsal view.
Weber’s length (WL) diagonal length of mesosoma in lateral view from the postero-ventral margin of propodeal lobe to anterior-most point of pronotal slope, excluding the neck.
Propodeal spine length (PSL) in dorsocaudal view, tip of the measured spine, its base, and center of propodeal concavity between spines must all be in focus. Using a dual-axis micrometer spine length is measured from tip of spine to a virtual point at its base where spine axis meets orthogonally with a line leading to median point of the concavity.
Petiolar node length (PTL) maximum length of dorsal face of petiolar node measured in dorsal view, excluding peduncle.
Petiolar node height (PTH) maximum height of petiolar node measured in lateral view from the highest (median) point of the node to ventral outline. The measuring line is placed in an orthogonal angle to ventral outline of node.
Petiolar node width (PTW) maximum width of dorsal face of petiolar node measured in dorsal view.
Postpetiole length (PPL) maximum length of postpetiole measured in dorsal view.
Postpetiole height (PPH) maximum height of postpetiole measured in lateral view from the highest (median) point of the node to the ventral outline. The measuring line is placed in an orthogonal angle to ventral outline of the node.
Postpetiole width (PPW) maximum width of postpetiole measured in dorsal view.
Ocular index (OI): EL / HW × 100
Cephalic index (CI): HW / HL × 100
Scape index (SI): SL / HW × 100
Propodeal spine index (PSLI): PSL / HL × 100
Petiolar node index (PeNI): PTW / PW × 100
Lateral petiole index (LPeI): PTL / PTH × 100
Dorsal petiole index (DPeI): PTW / PTL × 100
Postpetiolar node index (PpNI): PTW / PW × 100
Lateral postpetiole index (LPpI): PPL / PPH × 100
Dorsal postpetiole index (DPpI): PPW / PPL × 100
Postpetiole index (PPI): PPW / PTW × 100
The collection abbreviations follow
CASC California Academy of Sciences, San Francisco, California, U.S.A.
NHMB Naturhistorisches Museum, Basel, Switzerland.
KSMA King Saud University Museum of Arthropods, Plant protection department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia.
WMLC World Museum Liverpool, Liverpool, U. K.
The map was created by the ArcGIS 9.2 program, with the help of Prof. Mahmoud S. Abdeldayem (King Saud University).
Tetramorium latinode Collingwood & Agosti, 1996: 335, fig. 12 (w.) YEMEN. Holotype worker, YEMEN: Ma‘bar, pitfall trap, 11.v.1992 (M. Mahyoub & A. Drews) (WMLC).
Worker (Figs
Tetramorium latinode, worker (casent0906432, Saudi Arabia). 1 body in profile 2 body in dorsal view 3 head in full-face view. Photographer Estella Ortega, from www.AntWeb.org
Tetramorium latinode, queen (casent0906431, Saudi Arabia). 4 body in profile 5 body in dorsal view 6 head in full-face view. Photographer Estella Ortega, from www.AntWeb.org
34 workers, Saudi Arabia, Al Bahah, Amadan forest, Al Mandaq, 20°12.163'N, 41°13.906'E, 1881 m, 19.v.2010 (M. R. Sharaf & A. S. Aldawood Leg.); 1 worker, Saudi Arabia, Asir, Abha, Raydah, 18°11.679'N, 42°23.691'E, 1851 m, 8.vi.2014, (Pitfall trap) (Al Dhafer et al. Leg.); the following materials with data as the previous materials except coordinates and altitudes as follow: 1 worker, 18°11.618'N, 42°23.420'E, 1772 m; 2 workers, 18°11.695'N, 42°23.818'E, 1897 m; 2 workers, 18°12.265'N, 42°24.744'E, 2820 m; 5 workers, 18°12.315'N, 42°24.607'E, 2761 m; 5 workers, 18°12.095'N, 42°24.536'E, 2578 m. (KSMA).
Head little longer than broad with nearly straight or feebly convex sides; posterior margin of head weakly concave; eyes large and consist of 14 ommatidia in the longest row, EL about 0.27 × HW; antennae 12-segmented; frontal carinae long and sinuate, reaching back almost to posterior margin of head where they merge with the remaining sculpture of cephalic dorsum; antennal scrobes well developed; propodeal spines long and acute; petiole, postpetiole, pilosity and head sculpture as in worker. Bicoloured, body yellowish, gaster brown.
Tetramorium squaminode Santschi, 1911: 356, fig. (w) Tanzania.
Worker (Figs
Tetramorium squaminode, worker (casent0914585, Saudi Arabia). 7 body in profile 8 body in dorsal view 9 head in full-face view. Photographer Michele Esposito, from www.AntWeb.org
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
Tetramorium squaminode, queen (casent0914584, Saudi Arabia). 10 body in profile 11 body in dorsal view 12 head in full-face view. Photographer Michele Esposito, from www.AntWeb.org
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.
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).
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.).
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.
1 | Strongly bicoloured species, head, mesosoma, petiole and postpetiole yellow, gaster brown to brownish yellow; eyes with ten ommatidia in the longest row; posterior margin of head concave; pronotal corners angled from above; posterior margin of head with hairs of more or less equal lengths; clubbed pilosity distributed over the entire body (Yemen & KSA) | T. latinode Collingwood & Agosti |
– | Weakly bicoloured species with cephalic dorsum and gaster dark brown, lateral head, mesosoma, petiole and postpetiole of lighter brown; eyes with 13 ommatidia in the longest row; posterior margin of head nearly straight; pronotal corners rounded from above; posterior margin of head with one pair of characteristically longer hairs on both corners; clubbed pilosity restricted to the gaster, few on mesosoma (KSA) | T. squaminode Santschi |
1 | Strongly bicoloured, mesosoma, petiole, postpetiole, antennae and legs yellowish, head dorsum yellowish with scattered brownish tint, gaster brown; posterior margin of head distinctly concave; frontal carinae with only two pairs of hairs straddling the entire length, posterior corners of head without a single pair of longer hairs, instead about 8 subdecumbent hairs straddling the corners (Figs |
T. latinode Collingwood & Agosti |
– | Weakly bicoloured species with, head, mesosomal dorsum, petiole and postpetiole dark brown or blackish brown, gaster dark blackish brown to black, antennae and legs yellowish; posterior margin of head straight; frontal carinae with five pairs of distinctly long hairs straddling the entire length, posterior corners of head with some short hairs and a characteristic single pair of longer hairs (KSA) | T. squaminode Santschi |
Geologically, the Ethiopian and Arabian Peninsula mountains and highlands were separated approximately 13 my by the formation of the Great Rift Valley through a rifting process as the African continental crust separated (
From another aspect, the regional distribution of the two species of the T. squaminode-group appears to be restricted to the southwestern Mountains of the Arabian Peninsula (Fig.
The project was funded by the National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, award number 12-ENV2484-02. We are grateful to Prince Bandar Bin Saud Al Saud, Head of the Saudi National Commission for Wildlife Conservation and Development for the appreciated support during the study. The authors are grateful to Francisco Hita Garcia and Peter Hawkes for valuable suggestions that improved the manuscript. Special thanks to Brian Fisher for appreciated editorial work, to Michele Esposito (California Academy of Sciences, San Francisco, USA) for assistance in photographing the specimens, to Lutfy Al Juhany for identifying plants and to Mahmoud Abdel-Dayem for making the map. The authors are grateful to Boris Kondratieff (Colorado State University) for giving substantial comments on the manuscript. Mostafa Sharaf thanks the following: Stephen Judd (Director of WML), Tony Hunter (Entomology curator, WML) for appreciated hospitality in UK and his wife Amal Alsaadany, and children Mohammed and Fayrouz for encouragements.