Research Article |
Corresponding author: Shahid Ali Akbar ( kingakbarali@gmail.com ) Academic editor: Simon van Noort
© 2017 Mostafa R. Sharaf, Shahid Ali Akbar, Abdulrahman S. Aldawood, Francisco Hita Garcia.
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, Akbar SA, Aldawood AS, Hita Garcia F (2017) Review of the ant genus Nesomyrmex Wheeler, 1910 (Hymenoptera, Formicidae, Myrmicinae) from the Arabian Peninsula. African Invertebrates 58(2): 21-37. https://doi.org/10.3897/AfrInvertebr.58.12782
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In this study, we review the Arabian species of the ant genus Nesomyrmex Wheeler. We provide species reviews for the two previously known species, N. angulatus (Mayr, 1862) and N. humerosus (Emery, 1896) and describe a new species N. zaheri sp. n. from Yemen based on the worker caste. An illustrated key to the Arabian species of the genus and montage photos of all three species are provided.
Afrotropical Region, identification key, systematics, taxonomy, new species, Kingdom of Saudi Arabia, Asir Province
The myrmicine ant genus Nesomyrmex Wheeler, 1910 is distributed in the subtropical and tropical regions of the Neotropical, Afrotropical, and Malagasy Regions. With currently 80 valid species, the genus is comparatively species-rich (
In the last decade the taxonomy of the Old World fauna, especially the Afrotropical Region, has received much attention.
Little taxonomic or biogeographical information is currently available for the Arabian Nesomyrmex, of which only two species are known. The wide-spread and common species, N. angulatus (
While treating the Arabian species of Temnothorax Mayr, 1861 (
Morphological examinations were made using a Nikon SMZ 1500 stereo zoom microscope. The images of the type are available at AntWeb (https://www.antweb.org). General terminology for ant morphology is based on
HL Head length: maximum distance from the midpoint of the anterior clypeal margin to the midpoint of the posterior margin of head, measured in full-face view. Impressions on the anterior clypeal margin and the posterior head margin reduce head length.
HW Head width: width of the head directly behind the eyes measured in full-face view.
SL Scape length: maximum scape length excluding basal condyle and neck.
EL Eye length: maximum diameter of compound eye measured in oblique lateral view.
PH Pronotal height: maximum height of the pronotum measured in lateral view.
PW Pronotal width: maximum width of the pronotum measured in dorsal view.
WL Weber’s length: diagonal length of the mesosoma in lateral view from the posteroventral margin of propodeal lobe to the anterior-most point of pronotal slope, excluding the neck.
PSL Propodeal spine length: in dorsofrontal view the tip of the measured spine, its base, and the centre of the propodeal concavity between the spines must all be in focus. Using a dual-axis micrometre the spine length is measured from the tip of the spine to a virtual point at its base where the spine axis meets orthogonally with a line leading to the median point of the concavity.
PTH Petiolar node height: maximum height of the petiolar node measured in lateral view from the highest (median) point of the node to the ventral outline. The measuring line is placed at an orthogonal angle to the ventral outline of the node.
PTL Petiolar node length: maximum length of the dorsal face of the petiolar node from the anterodorsal to the posterodorsal angle, measured in dorsal view excluding the peduncle.
PTW Petiolar node width: maximum width of the dorsal face of the petiolar node measured in dorsal view.
PPH Postpetiole height: maximum height of the postpetiole measured in lateral view from the highest (median) point of the node to the ventral outline. The measuring line is placed at an orthogonal angle to the ventral outline of the node.
PPL Postpetiole length: maximum length of the postpetiole measured in dorsal view.
PPW Postpetiole width: maximum width of the postpetiole measured in dorsal view.
OI Ocular index: EL / HW * 100
CI Cephalic index: HW / HL * 100
SI Scape index: SL / HW * 100
DMI Dorsal mesosoma index: PW / WL * 100
LMI Lateral mesosoma index: PH / WL * 100
PSLI Propodeal spine index: PSL / HL * 100
LPeI Lateral petiole index: PTL / PTH * 100
DPeI Dorsal petiole index: PTW / PTL * 100
LPpI Lateral postpetiole index: PPL / PPH * 100
DPpI Dorsal postpetiole index: PPW / PPL * 100
PPI Postpetiole index: PPW / PTW * 100
Schematic line drawings of a Nesomyrmex species illustrating the measurements used (reproduced from
Throughout the text we abbreviate the castes in the following way: “w” for worker(s), “q” for queen, and “m” for male.
The collection abbreviations follow
FHGC Francisco Hita Garcia personal collection, Okinawa Institute of Science and Technology, Onna-son, Okinawa, Japan
KSMA King Saud University Museum of Arthropods, Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia.
MCZC Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, U.S.A.
WMLC World Museum Liverpool, Liverpool, U.K.
Nesomyrmex angulatus (Mayr, 1862) [Oman, Saudi Arabia, Yemen]
= Nesomyrmex angulatus ilgii (Forel, 1894)
= Nesomyrmex latinodis (Mayr, 1895)
= Nesomyrmex angulatus concolor (Santschi, 1914)
Nesomyrmex humerosus (Emery, 1896) [Yemen]
Nesomyrmex zaheri Sharaf, Akbar & Hita Garcia, sp. n. [Yemen]
1 | Anterior clypeal lobe short, flat-margined, and never convex, lobe with a small median triangular projection (Fig. |
N. humerosus |
– | Anterior clypeal lobe always conspicuously developed, convex and rounded, never with a small median triangular projection (Fig. |
2 |
2 | Clypeus with median longitudinal carina (Fig. |
N. angulatus |
- | Clypeus without median longitudinal carina (Fig. |
N. zaheri |
Anterior cephalic dorsum (white ellipse around anterior clypeus) and body in profile (arrows indicating petiolar node). A, B N. humerosus (CASENT0906196 – Antweb, Estella Ortega 2013) C N. angulatus (CASENT0235552 – Antweb, Shannon Hartman 2011) D N. angulatus (CASENT0922010 – Antweb, Zachary Lieberman 2015).
Anterior cephalic dorsum showing mandibles and clypeus (white lines outlining mandibular teeth and white arrows indicating median longitudinal carina or absence thereof). A N. angulatus (CASENT0235552 – Antweb, Shannon Hartman 2011) B N. zaheri sp. n. (CASENT0906379 – Antweb, Estella Ortega 2013).
Leptothorax
angulatus
Mayr, 1862: 739 (w.). EGYPT.
Leptothorax
angulatus
r.
ilgii
Forel, 1894: 82 (w.). ETHIOPIA. Santschi 1912: 148 (q.). [Combination in L. (Goniothorax):
Leptothorax
latinodis
Mayr, 1895: 130 (w.). MOZAMBIQUE. [Combination in L. (Goniothorax):
Leptothorax
angulatus
var.
concolor
Santschi, 1914: 107, fig. 15 (w.) KENYA.
KENYA: Coast Province, Malindi, Arabuko Sokoke Forest, -3.29, 39.98, 10–15 m, coastal hard wood forest, 24.V.2001 (R.R. Snelling) (FHGC: 3w); Coast Province, Malindi, Arabuko Sokoke Forest, -3.321, 39.929, 50 m, coastal dry forest, VI.2009 (F. Hita Garcia & G. Fischer) (FHGC: 3w); Rift Valley Province, Laikipia, Ewaso Ngiro, near Mpala Research Centre, 0.30, 36.91, 1600 m, Acacia woodland, 10.IV.2001 (R.R. Snelling) (FHGC: 10w); Rift Valley Province, Laikipia, Mpala Research Centre, 0.29, 36.9, 1650 m, Acacia woodland, 27.-28.IX.1999 and 24.III.2001 (R.R. Snelling) (FHGC: 3w); Western Province, Kakamega Forest, Buyangu Village, 0.3590, 34.8708, 1590 m, farmland, VII.2007 (F. Hita Garcia) (FHGC: 3w); MOZAMBIQUE: Sofala Province, Gorongosa National Park, Explore Gorongosa Park, -18.927, 34.378, 24 m, Fever tree forest, 20.V.2012 (G.D. Alpert) (MCZC: 3w); Sofala Province, Gorongosa National Park, 3 km W Chitengo, -18.992, 34.325, 37 m, riverine forest, 19.IV.2013 (G.D. Alpert) (MCZC: 3w); KINGDOM OF SAUDI ARABIA: Al Baha Province, Al Mukhwah, Dhi Ayn Archeological village, 19.929417°N, 41.441722°E, 741 m, 18.V.2010, (M. R. Sharaf) (KSMA: 3w); Elqamh park, Baljurshi, 19.913056°N, 41.905°E, alt. 1931 m, 17.V.2010, (M. R. Sharaf) (KSMA: 1w). Asir Province, Khamis Mushayt, W. Ben Hashbal, 18.594806°N, 42.650361°E, 1892 m, 26.IV.2011, (M. R. Sharaf) (KSMA: 6w); ZIMBABWE: Zebra Island, south side, -16.573, 28. 901, 12.V.2012 (J.K. Wetterer) (FHGC: 1w).
The following character combination distinguishes N. angulatus from the other members of the group in the Arabian Peninsula: third mandibular tooth relatively larger and better developed; anterior clypeal lobe always conspicuously developed, convex and rounded, never with a small median triangular projection; clypeus with median longitudinal carina; pronotum anterodorsally without sharp, dentate corners; in profile mesosomal dorsum forming a single, uninterrupted flat surface without any trace of metanotal groove; petiole with very well developed node.
(n=19). HL 0.70–0.91; HW 0.55–0.71; SL 0.50–0.67; EL 0.17–0.22; PH 0.26–0.41; PW 0.37–0.57; WL 0.75–1.21; PSL 0.05–0.14; PTL 0.17–0.27; PTH 0.20–0.34; PTW 0.20–0.34; PPL 0.15–0.26; PPH 0.17–0.30; PPW0.25–0.40; OI 27–35; SI 88–97; CI 76–86; DMI 44–56; LMI 30–37; PSLI 6–16; LPeI 57–88; DPeI 114–137; LPpI 68–91; DPpI 154–188; PPI 111–160.
As already pointed out by
This species exhibits remarkable variability throughout its distributional range, most notably in the shape of the petiolar node (
Nesomyrmex angulatus (CASENT0922010 – Antweb, Zachary Lieberman 2015). A Body in profile B Body in dorsal view C Head in full-face view.
Leptothorax (Goniothorax) humerosus
Emery, 1896: 62 (w.) EAST AFRICA (no locality given, very likely KENYA). [Combination in Nesomyrmex:
KENYA: Coast Province, Malindi, Arabuko Sokoke Forest, -3.321, 39.929, 50 m, coastal dry forest, VI.2009 (F. Hita Garcia & G. Fischer) (FHGC: 3w, 1q).
The following character combination distinguishes N. humerosus from the other members of the group in the Arabian Peninsula: anterior clypeal lobe short, flat-margined, and never convex, with small median triangular projection; clypeus without median longitudinal carina; pronotum anterodorsally sharply marginate, with sharp, dentate corners; in profile mesosomal outline conspicuously concave; petiole barrel-shaped with very weakly developed, short and triangular petiolar node.
(n=3). HL 0.74–0.75; HW 0.70–0.71; SL 0.58–0.59; EL 0.27–0.28; PH 0.34–0.35; PW 0.52–0.53; WL 0.89–0.92; PSL 0.19–0.20; PTL 0.12–0.13; PTH 0.24–0.25; PTW 0.21–0.22; PPL 0.15–0.16; PPH 0.21–0.22; PPW 0.33–0.34; OI 39; SI 83; CI 95; DMI 58; LMI 38; PSLI 26–27; LPeI 50–52; DPeI 169–175; LPpI 71–73; DPpI 213–220; PPI 155–157.
Nesomyrmex humerosus is currently only known to occur in Kenya, Tanzania, and Yemen. Very little is known about the biology of the species. Rarely collected species seems to live on vegetation but has also been sampled from the ground (
Nesomyrmex humerosus is the only member of the N. humerosus group and possesses an unusual character combination for an Afrotropical species due to its flat anterior clypeal margin, dentate pronotum, and barrel-shaped petiole. For more details see
Nesomyrmex humerosus (CASENT0906196 – Antweb, Estella Ortega 2013). A Body in profile B Body in dorsal view C Head in full-face view.
Holotype, pinned worker, YEMEN: Al Kawd, 13.088622° N, 45.364722° E, light-trap, 6770, 07.IX.2001, (A. van Harten) (WMLC: CASENT0906379).
The following character combination separates N. zaheri from the other Nesomyrmex species known from the Arabian Peninsula: third mandibular tooth relatively smaller and reduced; anterior clypeal lobe always conspicuously developed, convex and rounded, never with a small median triangular projection; pronotum anterodorsally without sharp, dentate corners; clypeus without median longitudinal carina; in profile mesosomal dorsum forming a single, uninterrupted flat surface without any trace of metanotal groove; petiole with very well developed node.
Holotype worker measurements. HL 0.71; HW 0.55; SL 0.49; EL 0.17; PH 0.30; PW 0.42; WL 0.83; PSL 0.07; PTL 0.17; PTH 0.21; PTW 0.18; PPL 0.12; PPH 0.21; PPW 0.24; OI 31; SI 89; CI 77; DMI 51; LMI 36; PSLI 10; LPeI 81; DPeI 106; LPpI 57; DPpI 200; PPI 133.
Head. Masticatory margin of mandible with four teeth, decreasing in size from largest, acute apical tooth to smallest basal denticle; clypeus smoothly arched-convex and without a small median triangular projection; head in full-face view appearing almost rectangular, longer than broad (CI 77), sides of head almost straight, broader posteriorly behind eye level and narrowest directly behind posterior eye margin; posterior head margin slightly concave medially; frontal carinae and antennal scrobes absent; antennal scapes short, not reaching posterior head margin (SI 89). Eyes of moderate size (OI 31), with eight to nine ommatidia in the longest row.
Mesosoma. In lateral view mesosomal outline relatively low (LMI 36) and flat without any metanotal groove; promesonotal suture present laterally and completely absent dorsally; pronotum marginate between lateral and dorsal mesosoma, anterodorsal corners slightly denticulate; propodeum armed with short propodeal teeth (PSLI 10); propodeal lobes moderately developed and rounded.
Waist segments and gaster. Petiolar peduncle moderate short; in profile petiolar node relatively high and narrowing from base to apex, around 1.2 times as high as long (LPeI 81); anterior and petiolar faces truncate; node in dorsal view weakly wider than long (DPeI 106) and denticulate; in profile postpetiole globular, about 1.8 times as high as long (LPpI 57); in dorsal view about twice as wide as long (DPpI 200); postpetiole in dorsal view around 1.3 times as wide as petiolar node (PPI 133).
Sculpture. Mandibles shagreened with prominent but weak, irregular, longitudinal rugulae; median clypeal carina absent, two lateral, longitudinal, rugae on each side; cephalic dorsum posteriorly and laterally weekly reticulate-rugose, medially mostly with conspicuously reticulate-punctulate ground sculpture; mesosoma laterally and dorsally with distinct reticulate-punctulate ground sculpture, lateral mesosoma also with few conspicuously longitudinal rugae; dorsum reticulate-rugose with some irregular, longitudinal elements medially; legs unsculptured, smooth and shining; petiole and postpetiole with prominent reticulate-rugose sculpture superimposed on reticulate-punctulate ground sculpture; gastral tergites mostly smooth and shiny.
Pilosity and pubescence. Head, mesosoma, waist segments and gaster dorsally with stout, erect, blunt, and moderately short pilosity; head laterally and ventrally with short appressed to decumbent pubescence; pubescence on mesosoma and waist segments sparse to absent; gastral tergites with short appressed to decumbent pubescence.
Coloration. Body uniformly light brown with head darker and the appendages lighter in colouration.
The patronym zaheri has been selected to honor the late famous Egyptian Qura’an reader Sheikh Abdel-Azim Zaher (1904–1971).
At present the new species is only known from the type locality, which is located near the Indian Ocean in southwestern Yemen near Aden. Nothing is known about the biology or nesting behavior of the species.
The new species is clearly a member of the N. angulatus species group sensu
Nesomyrmex zaheri sp. n. (CASENT0906379 – Antweb, Estella Ortega 2013). A Body in profile B Body in dorsal view C Head in full-face view.
Nesomyrmex is broadly distributed throughout the Afrotropical and the Malagasy Regions (
Due to the position of the Arabian Peninsula in the interchange of three biogeographical regions, the Palearctic, Oriental, and Afrotropical, it is not surprising to observe shared faunal elements between these regions. The southwestern mountains of the Kingdom of Saudi Arabia and Yemen exhibit strong biogeographical affinities with the Afrotropical fauna (
This work was supported by the Deanship of Scientific Research at King Saud University [RG-1438–010]. The authors are grateful to Brian Fisher (California Academy of Sciences, USA) for permission to use images on www.AntWeb.org, and Boris Kondratieff (Colorado State University, USA) for useful comments.