Temnothorax albispinus ( Wheeler, 1908 )

Prebus, Matthew M., 2021, Taxonomic revision of the Temnothorax salvini clade (Hymenoptera: Formicidae), with a key to the clades of New World Temnothorax, PeerJ (e 11514) 9, pp. 1-462 : 265-273

Temnothorax albispinus ( Wheeler, 1908)

Distribution: Fig. 133B ; worker, gyne & male: Fig. 135 ; variability: Fig. 136 .

Macromischa albispina Wheeler, 1908: 139 , pl. 11, figs. 3, 4. Syntype workers and gyne. U.S.A., Puerto Rico. One syntype worker here designated lectotype.

Macromischa (Antillaemyrmex) albispina (Wheeler) : Mann, 1920: 408. First combination in Macromischa (Antillaemyrmex) .

Macromischa (Antillaemyrmex) albispina var. pallipes Mann, 1920: 424 . Nomen nudum.

Antillaemyrmex albispina (Wheeler) : Wheeler, 1931: 27. First combination in Antillaemyrmex .

Antillaemyrmex albispina ssp. pallipes (Mann) : Wheeler, 1931: 27. Syntype workers and gyne; junior synonym of Temnothorax albispinus by Baroni Urbani, 1978: 413.

One syntype worker here designated lectotype.

Leptothorax albispina (Wheeler) : Baroni Urbani, 1978: 413. First combination in Leptothorax .

Temnothorax albispinus (Wheeler) : Bolton, 2003: 271. First combination in Temnothorax .

Type material examined: 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) [ MCZC].

Lectotype worker of Macromischa (Antillaemyrmex) alibispina pallipe s : 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].

Non-type material examined: U.S.A.: Puerto Rico: Coamo Springs, 1 worker, 1 dealate gyne (LACMENT323175) [ LACM]; Guánica Forest 17.960000 ° N 66.870000 ° W, 28 August 2000, J.A. Torres, ex sifted leaf litter, 1 dealate gyne & 2 workers (LACMENT323245) [ LACM]; same data as previous, except: 1 January 2000 J.A. Torres, ex sifted leaf litter, 4 workers (LACMENT323247) [ LACM]; Guánica Forest, 17.840000 ° N 66.860000 ° W, 14 June 1997, M. Canals, lite trap, 1 male (LACMENT323241) [ LACM] 1 male (LACMENT323242) [ LACM] 1 male (LACMENT323246) [ LACM]; 17.972000 ° N 66.868000 ° W, 120 m, 20 September 1998, R.R. Snelling#98-239, #1998-239, subtropical deciduous forest, ex rotten stick in leaf litter, 2 workers (LACMENT323243) [ LACM]; 17.966667 ° N 66.883333 ° W, 0–50 m, 30 May 1993, J. Longino#JTL3493-s, dry forest, sifted leaf litter sample, taken from moist litter in ravine, 1 worker (LACMENT002310) [ LACM] 2 workers (LACMENT002311) [ UCDC]; same data as previous, except: J. Longino#JTL3494-s, dry forest, strays from first site, 1 worker (LACMENT002269) [ LACM]. Guánica Forest, 7 June 1991, J. Torres#592, 2 workers, 1 dealate gyne (LACMENT323244) Isla de Mona: 30 June 1982, J.A. Torres#65, 3 workers (LACMENT323169) [ LACM]; Maygüez: Isla de Mona, 4 July 1982, J.A. Torres#255, 2 workers (LACMENT323170) [ LACM]; Isla de Mona, 5 min E of antenna, 18.100000 ° N 67.927000 ° W, 3 June 2006, J.K. Wetterer#272, 2 workers (MCZENT00505426) 2 workers (MCZENT00505427) [ MCZC]; Isla de Mona, 50 min E of antenna, 18.090000 ° N 67.910000 ° W, 3 June 2006, J.K. Wetterer#282, 1 dealate gyne (MCZENT00505431) [ MCZC]; Isla de Mona, Los Cerezos, 18.089000 ° N 67.900000 ° W, 3 June 2006, James K. Wetterer#277, forest, 1 worker (CASENT0756097) [ MMPC] 1 male (CASENT0756098) [ MMPC]; Isla de Mona, near antenna, 18.910000 ° N 67.936000 ° W, 40 m, 2 June 2006, J.K. Wetterer#JKW-2006-250, 1 worker (CASENT0758674) [ UCDC]; Isla de Mona, 21-26 February 2014, 3 workers (CASENT0758358) [ USNM]; Isla de Mona, 11-31 August 1944, Harry A. Beatty, 1 worker (CASENT0758359) [ USNM]; Cayo Luis Peña, 10 Sept 1982, J.A. Torres#51b, 3 workers (LACMENT323171) [ LACM]; Isla Piñeras, Humacao 11 March 1982, J.A. Torres#109, 3 workers (LACMENT323172) [ LACM]; Cayo Ratones, 17 July 1982, J.A. Torres#252, 1 worker (LACMENT323173) [ LACM]; Caja de Muertos, 27 September 1980, coll. J.A. Torres#51, 3 workers (LACMENT323174) [ LACM] 3 workers (CASENT0759975) [ FSCA] .

Geographic range: Low elevations of Puerto Rico and its small outlying islands ( Fig. 133B ).

Worker diagnosis: Temnothorax albispinus can be separated from all other species in the salvini clade by the following character combination: head in full face view with posterior margin flat to slightly convex; mesosoma compact; in profile view, dorsum of mesosoma evenly convex; metanotal groove not impressed; propodeum not depressed below the level of the promesonotum; propodeum bearing standing setae dorsally; propodeal spines about as long as the propodeal declivity, directed posteriorly, and straight to downcurved; in dorsal view, propodeal spines broadly approximated basally, the negative space between them “U” shaped; hind femora moderately to strongly incrassate; petiolar node rounded dorsally; in dorsal view, apex of petiolar node narrower or slightly wider than the caudal cylinder of the petiole; petiolar node with four erect setae dorsally; postpetiole very broad: greater than 2.5 times the width of the petiole; median clypeal carina well-defined; dorsum of head uniformly areolate; mesosoma bearing more than ten erect setae dorsally; setae on head, mesosoma, waist segments and gaster erect, moderately long, sparse and blunt (never long and tapering); integument variously colored: either predominantly dark brown, with light yellow antennal funiculus, tibiae, tarsi, and propodeal spines, or femora and antennal scapes yellow in addition to the preceding body parts, or uniformly yellow.

Similar species: Temnothorax agavicola sp. nov., T. laticrus sp. nov., T. torrei , T. wettereri sp. nov., and members of the pastinifer group. Temnothorax albispinus can be separated from most members of the pastinifer group, by the petiolar node, which not squamiform and relatively narrow in dorsal view: 0.9 to 1.1 times the width of the caudal cylinder of the petiole in T. albispinus vs. greater than 1.3 times in the pastinifer group. The petiolar node shape, in addition to the long propodeal spines and relatively narrow hind femora will distinguish T. albispinus from T. laticrus sp. nov. The erect setae count of four on the dorsum of the petiolar node differentiates T. albispinus from T. torrei , which has only two along the posterior margin. The flat to weakly convex posterior margin of the head of T. albispinus contrasts with T. agavicola sp. nov., which has a weakly concave posterior head margin. The body of T. wettereri sp. nov. is mostly devoid of erect setae, whereas T. albispinus has more than ten erect setae on the dorsum of the mesosoma.

Worker measurements & indices (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).

Worker description: 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.

Gyne measurements & indices (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).

Gyne description: 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 measurements & indices (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).

Male description: 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.

Etymology: Morphological, from the Latin ‘albus’ (= white) + ‘spinus’ (= spined), in reference to the lightly colored integument of the propodeal spines.

Comments: Temnothorax albispinus is known mostly from collections made on xerophytic islands surrounding Puerto Rico; known only from a couple of localities on the main island: the vicinity of Coamo Springs, and a light form from Guánica State Forest. Only one record of their nesting habits has appeared in the literature: Wheeler (1908), when describing the type series, noted: “a single colony which was found nesting in a small cavity in the ground in the shade of a thicket, where some of the workers were moving about slowly over the dead leaves and twigs.” Additional collections of the light form have been from either from soil beneath a stone, from rotten sticks in the leaf litter, or from Winkler extraction of leaf litter. An unpublished study by Snelling & Torres notes that it is attracted to tuna fish baits placed on the soil but has never been observed at baits placed on vegetation, even in localities where it is common. Apparently heat tolerant, workers have been observed foraging at baits during the midday hours, when soil surface temperatures probably exceed 45 ° C (R. R. Snelling & J.A. Torres, 2001, unpublished data). Males have been collected at light traps in Guánica State Forest, but queens have only been collected from nests or from sifting leaf litter. Based on the presence of multiple dealate gynes in nest series, T. albispinus may be polygynous, but only dissections of the gynes can rule out functional monogyny. This species, like other members of the pulchellus group, is probably ground or leaf litter nesting. Populations from Mona Island, which correspond to subspecies pallipes Wheeler, appear to be highly variable in the amount of infuscation on their appendages, ranging from the entirety of the legs being light yellow to the femora and antennal scapes being medium brown. However, another difference between T. albispinus pallipes and T. albispinus s.s. noted by Wheeler (1931), the absence of sculpture on the dorsal surface of the petiolar node, appears to occur only in the Isla de Mona populations. The amount of sculpture on the first gastral tergite appears to vary throughout the range of T. albispinus as well: at the extreme end, the anterior 2/3 of the tergite is weakly sculptured in the Coamo Springs worker. Nest series of workers indicate that the extent of femoral incrassation is at least somewhat dependent on worker size. The light form of this species has been determined as T. torrei in Torres & Snelling, 1997 and in the unpublished manuscript by Snelling & Torres, which is a review of the ants of Puerto Rico ( Fig. 136 ). It is easily separated from T. torrei by the larger size and presence of four erect setae on the dorsum of the petiole. Recognition of this species also explains what was interpreted as a disjunct distribution of T. torrei in Torres & Snelling, 1997. Temnothorax torrei , like many other Temnothorax species , has a Bahamian-Cuban distribution; it has never been collected from the island of Hispaniola. This species has long been suspected to have close relationships to other members of the salvini clade: specifically, T. androsanus , T. pastinifer , and T. subditivus ( Wheeler, 1908) . Baroni Urbani (1978) lumped them into the heterogeneous pulchellus group. In the first formal morphology-based phylogenetic work including this species, Fontenla Rizo (2000), while not including all of the taxa in Baroni Urbani’ s pulchellus group, corroborated these relationships to some degree, with the caveat that T. terricola and T. torrei fell outside of this group. Combined molecular and morphological analyses (M. Prebus, 2021, unpublished data) mostly agree with Fontenla Rizo (2000).

Figures

Figure 133 Geographical and elevational distribution of the pulchellus group. (A) Temnothorax agavicola sp. nov. (B) T. albispinus. (C) T. bahoruco sp. nov. (D) T. balaclava sp. nov. (E) T. ciferrii (F) T. flavidulus (G) T. harlequina sp. nov. (H) T. hippolytus sp. nov. (I) T. laticrus sp. nov. (J) T. magnabulla sp. nov. (K) T. pulchellus (L) T. terricola (M) T. torrei (N) T. wettereri sp. nov. (O) T. wilsoni sp. nov. Colored scale to the left of each map represents elevation in meters. Points in black represent the species named in each subfigure, while points in red represent other members of the species group. Type localities are represented by triangles; if present, types of synonyms are named; non-type localities are represented by circles. Bounding box in inset map shows location of main map. Full-size DOI: 10.7717/peerj.11514/fig-133

Figure 135 Temnothorax albispinus. (A–C) Worker (CASENT0756097). (A) Full-face view. (B) Profile view. (C) Dorsal view. (D–F) Gyne (MCZENT00505431). (D) Full-face view. (E) Profile view. (F) Dorsal view. (G–J) Male (CASENT0756098). (G) Full-face view. (H) Profile view. (I) Forewing. (J) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-135

Figure 136 Light form of Temnothorax albispinus. (A–C) Worker (LACMENT323245). (A) Full-face view. (B) Profile view. (C) Dorsal view. (D–F) Gyne (LACMENT323245). (D) Full-face view. (E) Profile view. (F) Dorsal view.(G–J) Male (LACMENT323246). (G) Full-face view.(H) Profile view. (I) Wings. (J) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-136