Temnothorax albispinus

Wheeler (1931) reports this species has been observed nesting in soil under stones or leaves.

Identification
A synonymized form (Wheeler 1931): from Mona Island, off Porto Rico..... A worker and a dealated female in my collection measure only 1.5 and 2.6 mm. respectively, whereas the worker and female of the typical albispina measure 2-2.5 and 4 mm. In both castes of pallipes the legs, antennal scapes and mandibles are yellowish white and the petiolar node is distinctly smooth and shining. The antennal funiculi are slightly brownish.

Distribution based on Regional Taxon Lists
Neotropical Region: Greater Antilles, Puerto Rico.

Nomenclature

 *  albispinus. Macromischa albispina Wheeler, W.M. 1908a: 139, pl. 11, figs. 3, 4 (w.q.) PUERTO RICO. Combination in M. (Antillaemyrmex): Mann, 1920: 408; in Antillaemyrmex: Wheeler, W.M. 1931b: 27; in Leptothorax: Baroni Urbani, 1978b: 413; in Temnothorax: Bolton, 2003: 271. Senior synonym of pallipes: Baroni Urbani, 1978b: 413.
 * pallipes. Antillaemyrmex albispina subsp. pallipes Wheeler, W.M. 1931b: 27 (w.q.) PUERTO RICO (attributed to Mann). [Macromischa albispina var. pallipes Mann, 1920: 424. Nomen nudum.] Subspecies of albispinus: Smith, M.R. 1937: 851. Junior synonym of albispinus: Baroni Urbani, 1978b: 413.

Worker
Prebus (2021) - (n = 28): SL = 0.432-0.530 (0.487); FRS = 0.167-0.216 (0.190); CW = 0.518-0.641 (0.578); CWb = 0.456-0.590 (0.525); PoOC = 0.233-0.294 (0.265); CL = 0.563-0.694 (0.637); EL = 0.120-0.156 (0.139); EW = 0.091-0.116 (0.103); MD = 0.120-0.179 (0.147); WL = 0.608-0.763 (0.691); SPST = 0.190-0.276 (0.245); MPST = 0.184-0.250 (0.224); PEL = 0.259-0.350 (0.317); NOL = 0.161-0.231 (0.195); NOH = 0.093-0.147 (0.120); PEH = 0.172-0.238 (0.214); PPL = 0.171-0.240 (0.208); PPH = 0.209-0.297 (0.246); PW = 0.332-0.416 (0.386); SBPA = 0.125-0.180 (0.154); SPTI = 0.171-0.259 (0.218); PEW = 0.119-0.169 (0.146); PNW = 0.116-0.176 (0.148); PPW = 0.334-0.434 (0.385); HFL = 0.431-0.534 (0.492); HFWmax = 0.120-0.157 (0.141); HFWmin = 0.044-0.058 (0.050); CS = 0.738-0.937 (0.844); ES = 0.169-0.212 (0.191); SI = 86-97 (93); OI = 22-24 (23); CI = 79-87 (82); WLI = 123-138 (132); SBI = 25-33 (29); PSI = 31-39 (36); PWI = 247-281 (265); PLI = 121-178 (153); NI = 141-216 (164); PNWI = 85-117 (102); NLI = 56-78 (62); FI = 245-320 (283).

In full-face view, head subquadrate, longer than broad (CI 79-87). Mandibles weakly striate, shining, and armed with five teeth: the apical-most well developed, followed by a four roughly equally developed smaller teeth. Anterior clypeal margin entire to very slightly concave medially. Antennal scapes moderately long: when fully retracted, just reaching the posterior margin of the head capsule (SI 86-97). Antennae 12-segmented; antennal club of three segments, with the apical-most segment longer than the preceding two in combination. Frontal carinae very short, extending past the antennal toruli by the maximum width of the antennal scape. Compound eyes moderately protruding past the lateral margins of the head capsule. Lateral margin of head weakly convex, converging evenly to the mandibular insertions. Posterior head margin flat to very slightly convex, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 22-24), with 11 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a rounded ~120° angle. Mesosoma evenly, but weakly, convex dorsally from where it joins the pronotal neck to the propodeal spines. Promesonotal suture extending from the posterior margin of the procoxal insertion only to the mesothoracic spiracle, which is well developed. Metanotal groove nearly entirely absent: only visible as a faint disruption in the surface sculpture between meso- and metacoxal insertions to the minute metathoracic spiracle, which is nearly indistinguishable against the ground sculpture. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about three spiracle diameters. Propodeal spines well developed and moderately long (PSI 31-39), about as long as the propodeal declivity, tapering evenly from the base, evenly downcurved, and acute. Propodeal declivity straight and flat, forming a rounded ~100° angle with the base of the propodeal spines. Propodeal lobes rounded and very weakly developed. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole moderately long (PLI 121-178), without tubercles anterodorsally. Subpetiolar process in the form of a weakly developed, blunt tooth, which grades evenly into the ventral margin of the petiole posteriorly. Petiolar peduncle short, comprising about one third of the total length of the petiole. Petiolar node robust and erect: transition between peduncle and node marked by a rounded angle of ~120°, resulting in a strongly concave anterior node face; anterior face forming a rounded ~90° angle with the dorsal face, which is evenly convex; dorsal face rounding evenly into the posterior face, which is straight and forms a ~100° angle with the caudal cylinder. Postpetiole evenly rounded anterodorsally, before flattening posterodorsally; weakly lobed ventrally.

In dorsal view, humeri weakly developed: rounded and only slightly wider than the rest of the mesosoma; mesothoracic spiracles not protruding past the lateral margins of the mesosoma. Metanotal groove absent: mesonotum and propodeum completely fused and converging evenly to the bases of the propodeal spines. Propodeal spines broadly approximated basally and diverging apically, their apices separated from each other by slightly more than their length; negative space between them "U" shaped. Petiolar peduncle with spiracles slightly protruding past the lateral margins, the peduncle subtly constricted anterior to them. Petiolar node campaniform: rounded anteriorly, flatter posteriorly, slightly wider than the peduncle, and evenly grading into the caudal cylinder, which is slightly wider than the node. Postpetiole very broad (PWI 247-281) and campaniform, articulating with the entire anterior margin of the gaster. Anterior margin of the postpetiole broadly convex, with corners evenly rounding into the lateral margins, which evenly diverge to the angulate posterior corners; posterior margin broadly concave. Metafemur moderately to strongly incrassate (FI 245-320).

Sculpture: median clypeal carina present, flanked by additional faint carinae over weakly areolate ground sculpture. Antennal scapes weakly areolate and dull. Cephalic dorsum and lateral surfaces of head densely areolate; ventral surface shining through weaker areolate sculpture. Mesosoma with uniformly areolate sculpture, with the areolae subtly arranged into longitudinal rows on the dorsal faces of the pronotum, meso- and metapleurae; area directly anterior to the propodeal spiracle, as well as the area between the propodeal spiracle and base of the propodeal spines shining through weaker sculpture. Femora shining through weak areolate sculpture. Petiole smooth and shining ventrally, with shallow areolate sculpture surrounding the base of the petiolar node, which is mostly smooth and shining dorsally. Dorsal surface of postpetiole dull with weak costulae and shallow areolate sculpture. Gaster smooth and shining, with extensive spectral iridescence on the first tergite. Surface of the first gastral sternite smooth and shining, with weaker spectral iridescence.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Dorsum of head, mesosoma, waist segments and gaster with short, erect, blunt-tipped setae, the longest of which are roughly the width of the compound eye. The head bears ~28, mesosoma ~24, petiole 4, postpetiole ~12, and first gastral tergite ~44 setae. Sparse, adpressed pubescence present on the entire body, but only apparent on the gaster due to the dense ground sculpture on the rest of the body.

Color: head, mesosoma (except for propodeal spines), waist segments (except for strigil), and gaster are uniformly dark brown. Mandibles, extremities, and strigil are pale yellow.

Queen
Prebus (2021) - (n = 4): SL = 0.561-0.613 (0.591); FRS = 0.224-0.254 (0.243); CW = 0.776-0.807 (0.787); CWb = 0.715-0.758 (0.731); PoOC = 0.278-0.315 (0.301); CL = 0.716-0.775 (0.756); EL = 0.210-0.224 (0.217); EW = 0.160-0.185 (0.169); MD = 0.146-0.154 (0.150); WL = 1.153-1.262 (1.206); SPST = 0.282-0.328 (0.302); MPST = 0.304-0.342 (0.321); PEL = 0.384-0.466 (0.438); NOL = 0.212-0.265 (0.244); NOH = 0.131-0.176 (0.159); PEH = 0.256-0.310 (0.288); PPL = 0.210-0.297 (0.251); PPH = 0.316-0.359 (0.336); PW = 0.715-0.779 (0.757); SBPA = 0.354-0.374 (0.363); SPTI = 0.293-0.345 (0.327); PEW = 0.182-0.206 (0.196); PNW = 0.189-0.212 (0.201); PPW = 0.492-0.553 (0.533); HFL = 0.629-0.674 (0.655); HFWmax = 0.122-0.151 (0.139); HFWmin = 0.051-0.061 (0.057); CS = 1.073-1.142 (1.109); ES = 0.293-0.313 (0.301); SI = 78-86 (81); OI = 26-28 (27); CI = 92-100 (97); WLI = 161-172 (165); SBI = 48-52 (50); PSI = 23-28 (25); PWI = 260-284 (273); PLI = 148-189 (177); NI = 151-162 (154); PNWI = 100-105 (103); NLI = 55-57 (56); FI = 234-256 (245).

In full-face view, head subquadrate, roughly as long as broad (CI 92-100). Mandibles weakly striate, shining, and armed with five teeth: the apical-most well developed, followed by a four roughly equally developed smaller teeth. Anterior clypeal very slightly concave medially. Antennal scapes moderately long: when fully retracted, just reaching the posterior margin of the head capsule (SI 78-86). Antennae 12-segmented; antennal club of three segments, with the apical-most segment as long as the preceding two in combination. Frontal carinae very short, extending past the antennal toruli by one and a half times the maximum width of the antennal scape. Compound eyes moderately protruding past the lateral margins of the head capsule. Lateral margin of head slightly convex, converging evenly to the mandibular insertions. Posterior head margin flat to very slightly convex, rounding evenly into the lateral margins.

In profile view, compound eyes teardrop-ovular and large (OI 26-28), with 16 ommatidia in longest row. Mesoscutum rounded evenly anteriorly, covering the dorsal surface of the pronotum, and flat dorsally. Mesoscutellum depressed slightly below the level of the mesoscutum; posterior margin of mesoscutellum even with the posterior margin of the metanotum. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about four spiracle diameters. Propodeal spines stout and well developed, but short (PSI 23-28), about half as long as the propodeal declivity, tapering evenly from the base, straight, and directed posteriorly. Propodeal declivity straight and flat, forming a rounded ~90° angle with the base of the propodeal spines. Propodeal lobes rounded and very weakly developed. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole moderately long (PLI 148-189), without tubercles anterodorsally. Subpetiolar process in the form of a weakly developed, blunt triangular tooth, which grades evenly into the ventral margin of the petiole posteriorly. Petiolar peduncle short; comprising about one third of the total length of the petiole. Petiolar node erect: transition between peduncle and node evenly rounded, resulting in a very slightly concave anterior node face; anterior face forming a sharp ~90° angle with the dorsal face, which is evenly convex and short; dorsal face rounding evenly into the posterior face, which forms a ~130° angle with the caudal cylinder. Postpetiole evenly rounded anteriorly, dorsal face weakly bulging anterodorsally before flattening posteriorly; ventral surface lobed.

In dorsal view, mesoscutum covering pronotum anteriorly, but humeri visible laterally as rounded sclerites. Propodeal spines weakly diverging proximally, but converging distally, their apices separated from each other by about one and a half times their length. Petiolar peduncle with spiracles slightly protruding past the lateral margins, the peduncle broadened where they arise. Petiolar node weakly convex anteriorly, its shape roughly trapezoidal; posterior face of node indistinct. Petiolar node slightly wider than the peduncle, and evenly grading into the caudal cylinder, which is roughly the same width as the node. Postpetiole very broad (PWI 260-284), anteroposteriorly compressed, and campaniform, articulating with most of the anterior margin of the gaster, leaving small, angulate margins on each side of the gaster exposed. Anterior margin of postpetiole weakly convex, with corners evenly rounding into the lateral margins, which evenly diverge to the angulate posterior corners; posterior margin broadly concave. Metafemur weakly to moderately incrassate (FI 234-256).

Sculpture: median clypeal carina present, flanked by additional equally strong carinae over weakly areolate ground sculpture. Antennal scapes weakly areolate and moderately shining. Cephalic dorsum densely areolate, with weak longitudinal striae. Ventral surface of head weakly, but densely, areolate. Pronotal neck areolate. Pronotum, propodeum, and posterior halves of the anepisternum and katepisternum sculptured like the cephalic dorsum; anterior halves of anepisternum and katepisternum smooth and shining. Mesoscutum costulate with weak areolate sculpture; a small patch of smooth and shining sculpture present anteromedially. Mesoscutellum densely areolate, with a central strip of weaker, shining sculpture. Femora smooth and shining, with traces weak areolate sculpture on the distal quarter. Petiole covered with shallow areolate sculpture, which is weaker ventrally and on the angulate dorsal surface of the node. Dorsal surface of postpetiole dull, with weak costulae and shallow areolate sculpture. Gaster smooth and shining, with extensive spectral iridescence on the first, second, and third tergites. Surface of the and first gastral sternite smooth and shining, with weaker spectral iridescence.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Dorsum of head, mesosoma, waist segments and gaster with short, erect, blunt-tipped setae, the longest of which are roughly a third of the width of the compound eye. Sparse, adpressed pubescence present on the entire body, but only apparent on the gaster due to the dense ground sculpture on the rest of the body.

Color: head, mesosoma (except for propodeal spines), waist segments (except for strigil), and gaster are uniformly dark brown. Mandibles, extremities, and strigil are pale yellow.

Male
Prebus (2021) - (n = 4): SL = 0.312-0.338 (0.322); FRS = 0.137-0.177 (0.152); CW = 0.504-0.574 (0.534); CWb = 0.449-0.494 (0.470); PoOC = 0.190-0.202 (0.196); CL = 0.479-0.516 (0.499); EL = 0.209-0.228 (0.217); EW = 0.172-0.182 (0.177); MD = 0.056-0.069 (0.063); WL = 0.698-0.765 (0.737); SPST = n/a; MPST = 0.141-0.172 (0.156); PEL = 0.295-0.349 (0.322); NOL = 0.191-0.217 (0.203); NOH = 0.042-0.058 (0.050); PEH = 0.120-0.150 (0.130); PPL = 0.154-0.193 (0.174); PPH = 0.158-0.198 (0.181); PW = 0.445-0.519 (0.467); SBPA = n/a; SPTI = n/a; PEW = 0.115-0.130 (0.122); PNW = 0.123-0.155 (0.137); PPW = 0.262-0.339 (0.313); HFL = 0.523-0.649 (0.580); HFWmax = 0.069-0.084 (0.078); HFWmin = 0.036-0.039 (0.038); CS = 0.693-0.752 (0.719); ES = 0.295-0.315 (0.305); SI = 67-70 (69); OI = 42-43 (42); CI = 90-96 (94); WLI = 152-163 (157); SBI = n/a; PSI= n/a; PWI = 228-277 (256); PLI = 153-213 (186); NI = 341-481 (412); PNWI = 99-119 (112); NLI = 59-68 (63); FI = 177-221 (204).

In full-face view, head subovate, slightly longer than broad (CI 90-96). Mandibles weakly striate, shining, and armed with five teeth: the apical-most well developed, followed by a four roughly equally developed smaller teeth, and the basal-most two separated from the rest by a brief diastema. Anterior clypeal margin entire and evenly convex. Antennal scapes moderately long: when fully retracted, just reaching the posterior margin of the head capsule (SI 67-70). Antennae 13-segmented; antennal club of four segments, with the apical-most segment as long as the preceding two in combination. Frontal carinae very short, extending past the antennal toruli by one and a half times the maximum width of the antennal scape. Compound eyes strongly protruding past the lateral margins of the head capsule. Lateral margin of head convex, margin between the anterior margin of the compound eye and the mandibular insertions straight. Posterior head margin very slightly convex, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and large (OI 42-43), with 19 ommatidia in the longest row. Mesoscutum bulging anteriorly, covering the dorsal surface of the pronotum, flat dorsally, and rounded posteriorly. Mesoscutellum depressed slightly below the level of the mesoscutum, overhanging the very small metanotum. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about three spiracle diameters. Propodeal spines absent, indicated by weak carinae on the dorsal and declivitous faces of the propodeum, which converge into a rounded angle. Propodeal lobes rounded and weakly developed. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole long (PLI 153-213), without tubercles anterodorsally where it articulates with the mesosoma. Subpetiolar process absent. Petiolar peduncle short: comprising about one third of the total length of the petiole. Petiolar node low and rounded, the convergence of the anterior and dorsal faces marked by a rounded angle. Postpetiole evenly rounded anterodorsally, flattened dorsally, and with a lobed, concave ventral surface.

In dorsal view, mesoscutum covering pronotum anteriorly, humeri barely visible laterally as slivers of rounded sclerites. Petiolar peduncle with spiracles slightly protruding past the lateral margins, the peduncle broadened where they arise. Petiolar node slightly wider than the peduncle; petiole narrowed posterior to the node, before widening again to the caudal cylinder, which is slightly narrower than the node. Postpetiole very broad (PWI 228-277) and campaniform, articulating with most of the anterior margin of the gaster, leaving small, rounded margins on each side exposed. Anterior margin of postpetiole weakly convex, with the anterior corners evenly rounding into the lateral margins, which evenly diverge to the angulate posterior corners; posterior margin of postpetiole broadly concave. Metafemur not incrassate (FI 177-221).

Sculpture: median clypeal carina present, flanked by additional weak carinae over weakly areolate ground sculpture. Antennal scapes weakly shining through shallow areolate sculpture. Head uniformly densely areolate. Lateral surfaces of pronotum and propodeum moderately shining through weak areolate sculpture. Anepisternum and katepisternum smooth and shining with weak areolate sculpture on their posterior third. Dorsally, mesoscutum weakly areolate between the Mayrian furrows, with a small patch of smooth sculpture anteromedially; otherwise smooth and shining. Mesoscutellum weakly areolate. Femora smooth and shining, with traces weak areolate sculpture along the entire length. Petiole covered with shallow areolate sculpture, with the dorsal surface of the node smooth and shining. Dorsal surface of postpetiole shining, with traces of shallow areolate sculpture, especially on the posterior third. Gaster smooth and shining, with weak spectral iridescence on the first gastral tergite.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Dorsum of head, mesosoma, waist segments and gaster with short, erect, blunt-tipped setae, the longest of which are roughly a quarter of the width of the compound eye. Sparse, adpressed pubescence present on the entire body, but only apparent on the gaster due to the dense ground sculpture on the rest of the body.

Color: head, mesosoma, waist segments, and gaster are uniformly dark brown. Mandibles and extremities are pale yellow.

Type Material
Prebus (2021) – Syntype workers and gyne. U.S.A., Puerto Rico. One syntype worker here designated lectotype.

Lectotype worker of Macromischa albispina: U.S.A.: Puerto Rico: Culebra Island, W.M. Wheeler, TYPE No. A.M.N.H., specimen furthest from pin (images of M.C.Z. Type 1-3 21013 examined on the MCZ Type Database website).

Lectotype worker of Macromischa (Antillaemyrmex) alibispina pallipes: U.S.A.: Puerto Rico: Isla de Mona: Mona Passage, top specimen (images of MCZ Type 1-2 21014 syntype worker examined on the MCZ Type Database website) [MCZC].

Etymology
Morphological, from the Latin ʻalbus' (= white) + ʻspinus' (= spined), in reference to the lightly colored integument of the propodeal spines.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1978. Materiali per una revisione dei Leptothorax neotropicali appartenenti al sottogenere Macromischa Roger, n. comb. (Hymenoptera: Formicidae). Entomol. Basil. 3: 395-618.
 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Garcia M. A. The vulnerability of leaflitter ants to forest disturbances in the islands of Puerto Rico, Greater Antilles. Novitates Caribaea 13: 74-91.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Smith M. R. 1937. The ants of Puerto Rico. Journal of Agriculture of the University of Puerto Rico 20: 819-875.
 * Torres, Juan A. and Roy R. Snelling. 1997. Biogeography of Puerto Rican ants: a non-equilibrium case?. Biodiversity and Conservation 6:1103-1121.
 * Wheeler W. M. 1908. The ants of Porto Rico and the Virgin Islands. Bulletin of the American Museum of Natural History 24: 117-158.
 * Wheeler W. M. 1931. New and little-known ants of the genera Macromischa, Creosomyrmex and Antillaemyrmex. Bulletin of the Museum of Comparative Zoology 72: 1-34.
 * Wheeler W. M. 1937. Ants mostly from the mountains of Cuba. Bulletin of the Museum of Comparative Zoology. 81: 439-465.