Tetramorium atlante Cagniant, 1970

Lech Borowiec & Christophe Galkowski, 2016, REDESCRIPTION OF TETRAMORIUM ATLANTE CAGNIANT, 1970, NEW STATUS (HYMENOPTERA: FORMICIDAE: MYRMICINAE), Annales Zoologici 66 (1), pp. 43-52 : 44-50

Tetramorium atlante Cagniant, 1970 new status

( Figs 1 –13)

Tetramorium caespitum st. punicum var. atlantis Santschi, 1918: 155 (terra typica: Tunisia), unavailable name.

Tetramorium semilaeve subsp. atlante Cagniant, 1970: 430, 1997: 98 .

Material examined. Type material: syntype work- er on photo (AntWeb resources: Photo by Alexandra Westrich | URL: https://www.antweb.org/specimen/ CASENT0915045 ; accessed 1 April 2015): T. caespitum L. | st. punicum Sm | var. atlantis Sants | Type || Kairouan | (Santschi) || Tunisie | Kairouan | Dr. F. Santschi || 135 || Sammlung | Dr. F. Santschi | Kairouan || Type || NATURHIST. | MUSEUM | BASEL || ANTWEB | CASENT | 0 915045 ( NHMB).

Other material examined. 4 gynes, 5 males, 10 workers: Morocco | Meknès-Tafilale | Aïn Vittel n. Ifrane , 1600 m | 35.5409° / -5.113°, 10 VII 2010 | C. Galkowski || Collection L. Borowiec | Formicidae | LBC-MOR00010 ( DBET).

Redescription. Worker ( Figs 1–3 ). Measurements and indices (n=10): CL: 0.77 ± 0.03 (0.737–0.844); POC: 0.3 ± 0.02 (0.268–0.324); CW: 0.755 ± 0.04 (0.704– 0.866); FR: 0.27 ± 0.017 (0.257–0.313); FL: 0.271 ± 0.016 (0.257–0.313); SL: 0.535 ± 0.02 (0.506–0.575); OMD: 0.192 ± 0.015 (0.17–0.212); EL: 0.146 ± 0.08 (0.128–0.291); EH: 0.098 ± 0.01 (0.078–0.101); ML: 0.827 ± 0.039 (0.782–0.927); SPSP: 0.148 ± 0.013 (0.112–0.17); SPL: 0.106 ± 0.011 (0.089–0.126); PEL: 0.191 ± 0.014 (0.179–0.229); NOL: 0.153 ± 0.011 (0.134–0.179); PPL: 0.176 ± 0.007 (0.162–0.19); PEH: 0.25 ± 0.013 (0.235–0.282); NOH: 0.177 ± 0.016 (0.165–0.223); PPH: 0.243 ± 0.011 (0.229–0.268); MW: 0.471 ± 0.024 (0.441–0.531); PEW: 0.235 ± 0.013 (0.215–0.267); PPW: 0.261 ± 0.01 (0.246–0.285); CS: 0.763 ± 0.035 (0.721–0.855); EYE: 0.16 ± 0.01 (0.138– 0.167); CL/CW: 1.021 ± 0.02 (0.975–1.047); FR/CS: 0.353 ± 0.009 (0.341–0.367); FL/FR: 1.009 ± 0.01 (1.0–1.043); SL/CS: 0.703 ± 0.016 (0.672–0.741); MW/CS: 0.618 ± 0.008 (0.6–0.632); PEW/PPW: 0.902 ± 0.03 (0.857– 0.937); NOH/NOL: 1.163 ± 0.08 (1.057–1.336); NOH/ PEL: 0.928 ± 0.05 (0.852–1.0); NOL/PEL: 0.801 ± 0.04 (0.729–0.872); PEH/NOL: 1.637 ± 0.08 (1.538–1.722); PEW/PEH: 0.943 ± 0.03 (0.914–0.979); CS/PEW: 3.245 ± 0.07 (3.14–3.351); CS/PPW: 2.927 ± 0.08 (2.816– 3.065); CW/MW: 1.619 ± 0.02 (1.582–1.666).

Small to medium size, CS 0.763 [0.721–0.855]. Whole body brown to dark brown and appendages yellow, the palest specimens never yellow. Head nearly square CL/CW 1.021 [0.975–1.047], with almost parallel to slightly rounded sides, straight or slightly concave occipital margin and regularly rounded occipital corners. Eyes small, EYE 0.16 [0.138–0.167]. Frons moderately wide, FR/CS 0.353 [0.341–0.367], frontal lobes as wide as frons, FL/FR 1.009 [1.0–1.043]. Scape short, SL/CS 0.703 [0.672–0.741], without dorsal carina basally, surface smooth and shiny. Promesonotal dorsum slightly convex, metanotal groove shallow, but distinct. Propodeal teeth short, spiniform, apex of spine located approximately at 2/3 height of mesosoma ( Fig. 2 ). Dorsal surface of petiole flat, NOH/NOL 1.163 [1.057– 1.336], petiole relatively high, PEH/NOL 1.637 [1.538–1.722], postpetiole distinctly transverse. General appearance moderately rugose, ground surface finely sculptured. Head dorsum mostly longitudinally rugose and shiny between rugae, rugae extend occipital margin of head, occiput mostly smooth and shiny, sides in anterior half longitudinally rugose and shiny between rugae. In most specimens short band without rugosities runs between frontal rugose area and rugosities along ocular area on each side ( Fig. 3 ) but smooth area never exceeds 1/7 length of anterior surface of head; in extremely sculptured specimens almost entire frontal surface of head with long rugae with very small smooth patch between interrupted rugae and occiput with fine rugosities. Mesosoma dorsum longitudinally rugose and microreticulate but never reticulate, only occasionally rugae on pronotum partly interrupt- ed with indistinct microreticulation but pronotum nev- er with distinct smooth and shiny areas ( Fig. 1 ). Sides of pronotum and meso- and metapleuron usually coarsely microreticulate, sometimes reticulation tends to form transverse lines but surface never appears striate or rugose ( Figs 2 ). Dorsum of petiolar node smooth and shiny with sides carinate, lateral surface microreticulate. Dorsum of postpetiole smooth and shiny, sides microreticulate. First gastral tergite smooth and shiny. Whole dorsum, including head, covered with sparse setae, the longest on pronotum and the shortest on frons. Ventral surface of head with sparse short and 2–3 moderately long setae not forming a psammophore.

Gyne ( Figs 4–7 ). Measurements and indicates (n=3): CL: 1.05 ± 0.013 (1.039–1.065); POC: 0.388 ± 0.013 (0.374–.4); CW: 1.17 ± 0.02 (1.148–1.187); FR: 0.409 ± 0.007 (0.4–0.413); FL: 0.389 ± 0.01 (0.379– 0.398); SL: 0.727 ± 0.022 (0.704–0.749); OMD: 0.21 ± 0.016 (0.201–0.229); EL: 0.287 ± 0.007 (0.279–0.291); EH: 0.227 ± 0.02 (0.212–0.246); ML: 1.849 ± 0.001 (1.848–1.85); SPSP: 0.294 ± 0.02 (0.268–0.313); SPL: 0.216 ± 0.006 (0.212–0.223); PEL: 0.29 ± 0.02 (0.279– 0.313); NOL: 0.214 ± 0.008 (0.207–0.223); PPL: 0.315 ± 0.011 (0.302–0.324); PEH: 0.458 ± 0.011 (0.446–0.469); NOH: 0.287 ± 0.025 (0.257–0.302); PPH: 0.436 ± 0.007 (0.425–0.446); MW: 1.125 ± 0.01 (1.11–1.135); PEW: 0.39 ± 0.01 (0.38–0.4); PPW: 0.488 ± 0.02 (0.475–0.508); CS: 1.11 ± 0.014 (1.094–1.12); EYE: 0.232 ± 0.012 (0.224–0.246); CL/CW: 0.898 ± 0.015 (0.88–0.907); FR/CS: 0.368 ± 0.01 (0.357–0.378); FL/FR: 0.953 ± 0.04 (0.918–0.995); SL/CS: 0.655 ± 0.014 (0.644–0.671); MW/CS: 1.014 ± 0.09 (0.995–1.032); PEW/PPW: 0.801 ± 0.014 (0.787–0.815); NOH/NOL: 1.345 ± 0.168 (1.152– 1.459); NOH/PEL: 0.989 ± 0.08 (0.921–1.082); NOL/PEL: 0.74 ± 0.07 (0.661–0.799); PEH/NOL: 2.139 ± 0.03 (2.103–2.16); PEW/PEH: 0.853 ± 0.04 (0.83–0.897); CS/ PEW: 2.845 ± 0.106 (2.734–2.946); CS/PPW: 2.278 ± 0.12 (2.152–2.357); CW/MW: 0.987 ± 0.02 (0.967–1.005); WAIST: 0.792 ± 0.035 (0.764–0.83).

Moderate size, CS 1.11 [1.094–1.12]. Head and mesosoma dark brown, abdomen brown, appendages yellowish. Head wider than long, CL/CW 0.898 [0.88– 0.907], with straight subparallel sides, shallowly emarginate occipital margin and regularly rounded occipital corners. Frons moderately wide, FR/CS 0.368 [0.357– 0.378], frontal lobes as wide as frons, FL/FR 0.953 [0.918–0.995]. Scape short, SL/CS 0.655 [0.644–0.671], without dorsal carina basally, smooth and shiny. Head as wide as scutum, MW/CS 1.014 [0.995–1.032]. Propodeal teeth short, triangular. Dorsal crest of petiolar node in frontal view slightly convex. Petiolar node dorsum steeply rounded backward. Petiole and postpetiole relatively narrow, WAIST 0.792 [0.764–0.83]. General appearance partly sculptured. Head dorsum, occiput and sides distinctly rugulose, ground surface shiny or indistinctly microreticulate. Frons longitudinally rugulose ( Fig. 4 ). Mesosoma flat, pronotal sides visible from above. Anterior margin, sides, and median part of scutum smooth and shiny, lateral to shiny medi- an band punctate and longitudinally striate, striae extending from base to 2/3 length of scutum, in the strongest sculptured specimens median smooth band very narrow and whole base of scutum striate. Scutellum mostly smooth and shiny, only corners or corners and sides with oblique striation and punctate ( Fig. 5 ). Sides of pronotum ruguloso-reticulate and feebly microreticulate, anepisternum in upper part with fine longitudinal rugae and rest smooth and shiny, katepisternum mostly smooth and shiny but posterior corners and sometimes whole posterior third with fine longitudinal rugae and microreticulation ( Fig. 7 ). Whole surface of petiolar node distinctly reticulate, posterior surface granulate without or with indistinct transverse rugae. Postpetiole distinctly transverse, sides rounded ( Fig. 7 ), dorsum of postpetiole smooth, sides granulate and reticulate. First gastral tergite smooth and shiny. Whole dorsum, including head, covered with short, sparse setae. Ventral surface of head with several short setae, as long as to 1.5 times longer than frontal setae, arising posteriorly to buccal cavity.

Male ( Figs 8 –13). Measurements and indicates (n=5): CL: 0.694 ± 0.013 (0.673–0.715); POC: 0.284 ± 0.01 (0.268–.302); CW: 0.836 ± 0.014 (0.81–0.854); FR: 0.258 ± 0.009 (0.246–0.274); FL: 0.292 ± 0.006 (0.285– 0.302); SL: 0.311 ± 0.008 (0.302–0.324); OMD: 0.076 ± 0.007 (0.061–0.084); EL: 0.315 ± 0.008 (0.302–0.324); EH: 0.258 ± 0.005 (0.249–0.263); ML: 1.81 ± 0.113 (1.617–1.935); SPSP: 0.243 ± 0.01 (0.235–0.263); SPL: 0.216 ± 0.011 (0.201–0.232); PEL: 0.32 ± 0.011 (0.302– 0.335); NOL: 0.244 ± 0.019 (0.212–0.268); PPL: 0.304 ± 0.018 (0.279–0.324); PEH: 0.333 ± 0.01 (0.313–0.346); NOH: 0.206 ± 0.015 (0.19–0.235); PPH: 0.464 ± 0.029 (0.425–0.503); MW: 1.108 ± 0.049 (1.067–1.2); PEW: 0.36 ± 0.005 (0.351–0.366); PPW: 0.518 ± 0.02 (0.492– 0.547); CS: 0.765 ± 0.014 (0.742–0.785); EYE: 0.374 ± 0.002 (0.372–0.379); CL/CW: 0.831 ± 0.004 (0.824– 0.837); FR/CS: 0.337 ± 0.01 (0.32–0.349); FL/FR: 1.134 ± 0.06 (1.044–1.228); SL/CS: 0.407 ± 0.009 (0.395– 0.421); MW/CS: 1.449 ± 0.06 (1.389–1.565); PEW/PPW: 0.696 ± 0.03 (0.655–0.744); NOH/NOL: 0.85 ± 0.093 (0.739–0.955); NOH/PEL: 0.644 ± 0.05 (0.6–0.725); NOL/PEL: 0.762 ± 0.044 (0.702–0.821); PEH/NOL: 1.372 ± 0.08 (1.25–1.476); PEW/PEH: 1.084 ± 0.05 (1.014– 1.169); CS/PEW: 2.185 ± 0.06 (2.042–2.191); CS/PPW: 1.478 ± 0.06 (1.402–1.561); CW/MW: 0.691 ± 0.027 (0.639–0.719).

Whole body dark brown, appendages yellowish. Head behind eyes almost trapezoidal, occipital margin slightly convex, occipital corners subangulate. Scutum distinctly wider than head. Propodeum in profile with distinct angulation in position of propodeal teeth. Dorsal crest of petiolar node with obtuse transversal edge, slightly emarginated in frontal view. Head distinctly granulate, dull. Sides of pronotum microreticulate with fine transverse striation. Scutum between sutures in anterior part with oblique striation and microreticulate only along middle runs shiny band, laterally smooth and shiny, rest microreticulate with longitudinal and oblique striation. Scutellum at base and laterally with longitudinal striation, rest smooth and shiny. Anepisternum in anterior half smooth and shiny in posterior half with oblique striation, katepisternum in both dorsal angles distincty striate and microreticulate. Whole surface of petiolar node microgranulate and microreticulate, dull, postpetiole mostly microreticulate only top partly smooth and shiny. Whole surface of propodeum microreticulate, dull. First gastral tergite smooth and shiny. Male genitalia stout ( Figs 10 –13), in lateral distinctly slightly constricted before apex with obtuse inner angle, top shortly and sparsely pubescent, ventral and dorsal margins of parameres shallowly incised, top of inner margin of paramere before apical denticle straight, without dentiform plate extending beyond the sharp edge of paramere (Fig. 13).

Differental diagnosis. Tetramorium atlante and T. semilaeve at first glance look similar, and workers are especially difficult to identify. Males and gynes, however, have constant differences in the morphological characters and biometric data (see Table 1 ).

Workers of T. atlante differ from workers of T. semilaeve (in parentheses characters for T. semilaeve ) in brown to dark brown body (usually pale yellow to yellowish brown, occasionally brown), head sculpture with longitudinal rugosities, more distinct spread over the frontal surface with very small lateral areas without striation (rugosities less distinct on sides of frontal surface, usually with longitudinal areas without striation). Nevertheless, dark and strongly sculptured workers of T. semilaeve are extremely similar to T. atlante and a proper identification requires a nest sample with sexual forms. Workers of T. depressum Forel and T. punctatum Santschi , two other well-defined species of T. semilaeve complex, differ in reduced sculpture of head with at least half frontal surface smooth and shiny.

Gynes of T. atlante distinctly differ from gynes of T. semilaeve (characters for T. semilaeve in parentheses) in larger size with ML 1.848–1.850, MW 1.11– 1.35, CW 1.148–1.187 and SPL 0.212–0.223 (1.053– 1.813, 1.0–1.14, 0.978–1.161 and 0.173–0.201), scutum at base and laterally with striation extending from base to at least half length of scutum (scutum completely smooth and shiny or with short striation at base never extending to half length of scutum), scutellum with distinct striation in angles (completely smooth and shiny or with rudiments of striation), anepisternum in posterior half with distinct striation and microreticulation (mostly smooth and shiny), katepisternum along posterior margin with broad area of distinct sculpture (narrow area or reduced to posterior corners), postpetiole less transverse and more sculptured with smooth and shiny area reduced to the middle of top (postpetiole more transverse, less sculpture with whole dorsal surface smooth and shiny).

Males of T. atlante distinctly differ from males of T. semilaeve in higher petiole with NOH 0.19–0.235 and PEH 0.313–0.346 (0.156–0.179 and 0.257–0.313), lower SL/CS ratio 0.395–0.421 (0.436–0.478), head behind eyes trapezoidal (rounded), scutum between sutures mostly striate and microreticulate (mostly smooth and shiny), scutellum at whole base microreticulate and striate (completely smooth and shiny or in basal corners with fine sculpture), propodeum slightly angulate (round), anepisternum in posterior half with oblique striation (smooth and shiny, at most with few striae close to upper margin), katepisternum in both upper corners with broad microreticulate and striate area (narrow sculptured areas), male genitalia in lateral view distinctly constricted before apex (shallowly constricted) and top of inner margin of paramere without dentiform plate extending beyond the sharp edge of paramere (with dentiform plate).

Biological notes. Although locus typicus Kairouan in Tunisia is placed only 70 m a.s.l. Cagniant (1970, 1997) noted than T. atlante prefers mountainous habitats. Its known localities are mostly between 1600 m (our material) to 2300 m (Haut Atlas). Ants were collected in agricultural habitat such as farmlands, pastures, and in scrubs, luminous forests, roadsides. Preference for mountain habitats additionally differentiates T. atlante from T. semilaeve , which, according to Borowiec et al. (2015), prefers littoral habitats located usually below 700 m a.s.l. and only occasionally reach to the elevation of just over 1000 m a.s.l.

Figures

Figures 1 – 2. Tetramorium atlante Cagniant, worker: (1) dorsal view; (2) lateral view. Scale bar = 1 mm.

Figures 3 – 5. Tetramorium atlante Cagniant: (3) worker head, scale bar = 0.5 mm; (4) gyne head; (5) gyne mesosoma. Scale bar 4, 5 = 1 mm.

Figures 6 – 7. Tetramorium atlante Cagniant, gyne: (6) dorsal view; (7) lateral view. Scale bar = 1 mm.

Figures 8 – 9. Tetramorium atlante Cagniant, male: (8) dorsal view; (9) lateral view. Scale bar = 1 mm.

Figures 10 – 11. Tetramorium atlante Cagniant, male genitalia: (10) dorsal view; (11) ventral view; (12) lateral view; (13) apical view. Scale bar = 0.5 mm.