Temnothorax bahoruco, Prebus, 2021

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 : 274-280

Temnothorax bahoruco sp. nov.

Distribution: Fig. 133C ; worker & gyne: Fig. 137 .

Type material examined: Holotype worker: DOMINICAN REPUBLIC: Pedernales: Sierra de Bahoruco National Park , 18.29217 ° N 71.69448 ° W ± 30 m, 2,025 m, 30 March 2014, D. Lubertazzi #DL03802 , open pine forest, in dead tree trunk and soil, 1 worker ( CASENT0758817 ) [ MCZC].

Paratype workers and gyne: same data as holotype, 1 worker (CASENT0758816) [ MCZC] 1 worker (CASENT0758678) [ UCDC]; same data as previous, except: D. Lubertazzi #DL03803:003, open pine forest, in dead tree trunk and soil, 1 dealate gyne (MCZENT00521421) [ MCZC] .

Geographic range: High elevations of Hispaniola ( Fig. 133C ).

Worker diagnosis: Temnothorax bahoruco sp. nov. can be separated from all other species in the salvini clade by the following character combination: anterior clypeal margin flat; in profile view, dorsum of mesosoma weakly 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 posterodorsally, and weakly downcurved; in dorsal view, propodeal spines broadly approximated, the negative space between them “U” shaped; hind femora weakly incrassate; petiole 1.4 times the length of the postpetiole; in dorsal view, apex of petiolar node narrower to slightly broader than the caudal cylinder of the petiole; postpetiole very broad: greater than or equal to 2.4 times the width of the petiole; dorsum of head smooth and shining; petiolar node with four erect setae dorsally; setae on head, mesosoma, waist segments and gaster erect, moderately long, sparse and blunt (never long and tapering); integument tricolored: predominantly dark brown, with the mandibles, and propodeal spines light yellow; legs testaceous with light yellow joints and tarsi.

Similar species: Temnothorax balaclava sp. nov., T. ciferrii , T. harlequina sp. nov., T. hippolytus sp. nov., T. magnabulla sp. nov., T. pulchellus , T. schwarzi , T. terricola , and T. wilsoni sp. nov. The erect setae count of four on the dorsum of the petiolar node differentiates T. bahoruco sp. nov. from T. terricola and T. hippolytus sp. nov., which have only two along the posterior margin. The presence of erect setae on the propodeum distinguishes T. bahoruco sp. nov. from T. pulchellus . The relatively small metapleural gland bulla of T. bahoruco sp. nov., which reaches halfway to from the metacoxal insertion to the propodeal spiracle, distinguishes it from T. magnabulla sp. nov., in which it extends three quarters of the way or more. Temnothorax balaclava sp. nov. and T. harlequina sp. nov. can be separated most easily by the color of the integument: T. harlequina sp. nov. has a light yellow gaster which strongly contrasts with the darker integument of the rest of the body, whereas the gaster of T. bahoruco sp. nov. is always light dark brown. The mesosoma is of T. bahoruco sp. nov. is less arched and more densely sculptured in comparison to T. harlequina sp. nov. Temnothorax bahoruco sp. nov. could also be confused with T. schwarzi due to the smooth and shining head capsule, but the relatively narrow apex of the petiolar node of T. bahoruco sp. nov. will separate the two. The medially flat anterior clypeal margin of T. bahoruco sp. nov. will differentiate it from T. wilsoni sp. nov. and T. balaclava sp. nov., which have emarginate and rounded anterior clypeal margins, respectively. Temnothorax bahoruco sp. nov. can be further separated from T. balaclava sp. nov. by the relatively shorter petiole, which is about 1.4 times the length of the postpetiole, versus 1.5 to 1.6 times in T. balaclava sp. nov.

Worker measurements & indices (n = 3): SL = 0.530 –0.560 (0.546); FRS = 0.215 –0.235 (0.225); CW = 0.616 –0.641 (0.631); CWb = 0.569 –0.604 (0.589); PoOC = 0.268 –0.289 (0.275); CL = 0.651 –0.693 (0.675); EL = 0.138 –0.152 (0.147); EW = 0.112 –0.118 (0.115); MD = 0.145 –0.168 (0.160); WL = 0.733 –0.805 (0.772); SPST = 0.256 –0.263 (0.261); MPST = 0.241 –0.252 (0.246); PEL = 0.312 –0.338 (0.329); NOL = 0.189 –0.217 (0.199); NOH = 0.122 –0.144 (0.135); PEH = 0.225 –0.254 (0.241); PPL = 0.218 –0.242 (0.232); PPH = 0.253 –0.271 (0.259); PW = 0.402 –0.441 (0.422); SBPA = 0.196 –0.213 (0.204); SPTI = 0.244 –0.315 (0.283); PEW = 0.161 –0.168 (0.164); PNW = 0.154 –0.177 (0.169); PPW = 0.401 –0.436 (0.419); HFL = 0.510 –0.532 (0.523); HFWmax = 0.126 –0.137 (0.132); HFWmin = 0.044 –0.055 (0.050); CS = 0.895 –0.944 (0.926); ES = 0.194 –0.211 (0.205); SI = 92–93 (93); OI = 22; CI = 86–89 (87); WLI = 129–133 (131); SBI = 34–36 (35); PSI = 32–36 (34); PWI = 245–261 (255); PLI = 140–143 (142); NI = 131–178 (149); PNWI = 94–110 (103); NLI = 56–70 (61); FI = 244–286 (268).

Worker description: In full-face view, head subquadrate, longer than broad (CI 86–89). Mandibles weakly striate, shining, and armed with five teeth: the apical-most well developed, followed by a less developed preapical tooth and three equally-developed smaller teeth. Anterior clypeal margin flat medially. Antennal scapes moderately long: when fully retracted, just barely surpassing the posterior margin of the head capsule (SI 92–93). Antennae 12-segmented; antennal club of three segments, with the apical-most segment slightly longer than the preceding two in combination. Frontal carinae moderately long, extending past the antennal toruli by about two times 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, forming a continuous arc from the posterior of the head, converging below the compound eye to the mandibular insertions. Posterior head margin weakly concave to flat, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 22), with 9 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a rounded ~120 ° angle. Mesosoma evenly 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 visible as a disruption of the sculpture laterally from where it arises between the mid- and hind coxae to where it ends in the poorly developed metathoracic spiracle, which is nearly indistinguishable against the ground sculpture. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about two and a half spiracle diameters. Propodeal spines well developed and moderately long (PSI 32–36), about as long as the propodeal declivity, tapering evenly from the base, weakly downcurved, and acute. Propodeal declivity straight and flat, forming a rounded ~100 ° angle with the base of the propodeal spines. Propodeal lobes rounded and weakly developed. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole moderately long (PLI 140–143), without tubercles anterodorsally. Subpetiolar process in the form of a small, acute tooth; ventral margin of petiole weakly concave posterior to it. Petiolar peduncle short, comprising about one third the total length of the petiole. Petiolar node robust: transition between peduncle and node marked by a rounded angle of ~140 °, resulting in a weakly concave anterior node face; anterior face forming a rounded, ~100 ° angle with the dorsal surface, which is evenly convex; dorsal surface rounding evenly into the short posterior declivity, which forms a ~100 ° angle with the caudal cylinder. Postpetiole evenly rounded dorsally, and weakly lobed ventrally.

In dorsal view, humeri weakly developed: evenly rounded and slightly wider than the rest of the mesosoma; mesothoracic spiracles weakly protruding past the lateral margins of the mesosoma, visible as slight angles where the pronotum meets the mesonotum. 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 protruding past the lateral margins, peduncle slightly narrowed anterior to them. Petiolar node evenly ovular, but slightly flatted posteriorly; node slightly wider than the peduncle, and evenly grading into the caudal cylinder, which is slightly narrower than the node. Postpetiole very broad (PWI 245–261) and campaniform, articulating with the nearly the entire anterior margin of the gaster. Anterior margin of the postpetiole flat and evenly rounds into the lateral margins, which diverge to the angulate posterior corners; posterior margin broadly concave. Metafemur weakly to moderately incrassate (FI 244–286).

Sculpture: median clypeal carina present, extending posteriorly nearly to the frontal triangle, and flanked on either side by two equally strong carinae. Lateral clypeal lobes with additional, weaker carinae; ground sculpture smooth and shining. Antennal scapes smooth and shining through weak areolate ground sculpture. Cephalic dorsum smooth and shining, but with covered with coarse piligerous punctures; costulae flanking the frontal carinae. Lateral surfaces of head with weak areolate sculpture posterior to the compound eye, dense rugose sculpture surrounding the compound eye, and weak rugae between the compound eye and the mandibular insertion. Ventral surface of head smooth and shining. Pronotal neck areolate. Lateral surface of the pronotum with weak costulate that are joined by rugulae. Mesopleurae and lateral surface of propodeum areolate-rugulose, with weaker sculpture between the propodeal spiracle and the propodeal spines. Dorsal surface of mesosoma uniformly areolate-rugulose. Femora shining, with weak areolate sculpture on the distal quarter. Dorsal surface of peduncle and ventral surface of petiole smooth and shining, with weak areolate sculpture on all other surfaces. Postpetiole smooth and shining, with weak areolate sculpture on the posterior quarter. Gaster smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Dorsum of head, pronotum, waist segments and gaster with moderately abundant, erect, blunt-tipped setae, the longest of which are about the width of the compound eye. The head bears ~24, mesosoma ~10, petiole 4, postpetiole ~10, and first gastral tergite ~20 setae. Short, sparse pubescence present over the entire body.

Color: predominantly dark brown, with the mandibles, bases of antennal scapes, and propodeal spines light yellow. Distal parts of the antennal scape, antennal funiculus, dorsum of mesosoma, and petiolar node testaceous. Legs testaceous with light yellow joints and tarsi.

Gyne measurements & indices (n = 1): SL = 0.570; FRS = 0.270; CW = 0.794; CWb = 0.736; PoOC = 0.288; CL = 0.746; EL = 0.244; EW = 0.188; MD = 0.147; WL = 1.304; SPST = 0.296; MPST = 0.296; PEL = 0.416; NOL = 0.200; NOH = 0.167; PEH = 0.315; PPL = 0.222; PPH = 0.391; PW = 0.807; SBPA = 0.354; SPTI = 0.356; PEW = 0.251; PNW = 0.233; PPW = 0.528; HFL = 0.673; HFWmax = 0.129; HFWmin = 0.053; CS = 1.109; ES = 0.338; SI = 77; OI = 30; CI = 99; WLI = 177; SBI = 48; PSI = 23; PWI = 210; PLI = 187; NI = 120; PNWI = 93; NLI = 48; FI = 243.

Gyne description: In full-face view, head subquadrate, about as long as broad (CI 99). Mandibles striate but shining and armed with five teeth: the apical-most well developed, followed by a less developed preapical tooth and three equally-developed smaller teeth. Anterior clypeal margin flat medially. Antennal scapes moderately long: when fully retracted, just reaching the posterior margin of the head capsule (SI 77). Antennae 12-segmented; antennal club composed of three segments, with the apical-most segment as long as the preceding two in combination. Frontal carinae moderately long, extending past the antennal toruli by about three times the maximum width of the antennal scape. Compound eyes moderately protruding past the lateral margins of the head capsule. Lateral margin of head evenly convex, converging from below the compound eyes to the mandibular insertions. Posterior head margin flat, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and large (OI 30), with 18 ommatidia in the longest row. Mesoscutum rounded evenly anteriorly, covering the dorsal surface of the pronotum, and flat dorsally. Mesoscutellum on the same level as the mesoscutum, not overhanging the metanotum. Posterior margin of metanotum extending past the posterior margin of the mesoscutum. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about four spiracle diameters. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Propodeal spines stout and well developed, but short (PSI 23), about as two thirds as long as the propodeal declivity, tapering evenly from the base, directed posteriorly, straight, and blunt. Propodeal declivity straight and flat, forming a rounded ~100 ° angle with the base of the propodeal spines. Propodeal lobes rounded and weakly developed. Petiole moderately long (PLI 187), without tubercles anterodorsally. Subpetiolar process in the form of a small, triangular, very acute tooth, which grades evenly into the ventral margin of the petiole posteriorly. Petiolar peduncle short: petiolar node covering most of the petiolar dorsum. 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 short. Dorsal face of petiolar node joins the posterior face at a ~120 ° angle. Posterior face of petiolar node forms a ~120 ° angle with the caudal cylinder. Postpetiole evenly rounded anterodorsally, bulging slightly before it transitions into the flattened dorsal face; ventral surface weakly convex.

In dorsal view, mesoscutum covering pronotum anteriorly, but humeri visible laterally as rounded sclerites. Propodeal spines diverging apically, their apices separated from each other by about two times their length. Petiolar peduncle with spiracles protruding past the lateral margins. Petiolar node trapezoidal: widest anteriorly, and emarginated anterodorsally; lateral faces converge to the posterior face. Petiolar node slightly narrower than the peduncle, and evenly grading into the caudal cylinder, which is slightly wider than the node. Postpetiole moderately broad (PWI 210), anteroposteriorly compressed, and subquadrate, articulating with most of the anterior margin of the gaster, leaving small, angulate margins on each side exposed. Anterior margin of postpetiole broadly concave, with corners evenly rounded as they transitions to the lateral margins, which are roughly parallel to the angulate posterior corners; posterior margin broadly concave. Metafemur weakly incrassate (FI 243).

Sculpture: median clypeal carina present, extending from the anterior margin nearly to frontal triangle, and flanked by weaker, indistinct carinae; lateral margins of median clypeal lobe with two carinae that are as strong as the medial carina. Lateral clypeal lobes with additional weaker carinae; ground sculpture smooth and shining. Antennal scapes smooth and shining. Cephalic dorsum with costulae, which become weaker posteriorly; a strip of smooth sculpture present medially, surrounding a central carina, which extends from the frontal triangle nearly to the median ocellus. Lateral surfaces of head with weak areolate sculpture posterior to the compound eye, dense rugose sculpture surrounding the compound eye, and rugae between the compound eye and the mandibular insertion. Ventral surface of head with weak rugae and areolae. Pronotal neck areolate. Pronotum with weak areolate ground sculpture arranged into longitudinal rows and separated by superficial striae. Anepisternum and katepisternum shining on their anterior halves, transitioning into weak costulae over weak areolae posteriorly. Propodeum areolate laterally and on the propodeal declivity; sculpture weaker between the propodeal spiracle and the base of the propodeal spine. Mesoscutum with costulae which are weaker anteromedially and laterally. Mesoscutellum smooth and shining medially, surrounded by dense striae and areolae. Femora smooth and shining, with traces of weak areolate sculpture distally. Petiole areolate laterally and on the dorsal surface of the node; peduncle smooth and shining dorsally; base of petiolar node with rugulae. Postpetiole smooth and shining anteriorly, areolate laterally and on the posterior half. Gaster smooth and shining, without spectral iridescence. Surface of the first gastral sternite smooth and shining.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Dorsum of head, pronotum, waist segments and gaster with moderately abundant, erect, blunt-tipped setae, the longest of which are about half the width of the compound eye. Short, sparse pubescence present over the entire body.

Color: predominantly dark brown, with the mandibles, bases of antennal scapes, and propodeal spines light yellow. Distal parts of the antennal scape and antennal funiculus testaceous. Legs testaceous with light yellow joints and tarsi.

Male: Unknown.

Etymology: Bahoruco, a word from the Macorix language of the people of the northern coast of Hispaniola meaning “within the forest”, a reference to the mountain range and habitat in which the type specimens were collected.

Comments: Temnothorax bahoruco sp. nov. is known only from high elevation Pinus occidentalis forests in the Sierra de Bahoruco, where workers and a dealate gyne were collected from a dead tree trunk and the surrounding soil. Other details of the biology of this species are unknown but are probably similar to other members of the terricolous pan-Caribbean pulchellus group. In the limited number of specimens that I observed from this series, this species displays some variation in coloration of the mesosoma and waist segments, ranging from being completely dark brown to dorsally testaceous. This taxon is part of a species complex with T. balaclava sp. nov., T. ciferrii , and Temnothorax wilsoni sp. nov., all of which have only been collected from allopatric populations in mountains and low-lying dry forest from the southern parts of Hispaniola. The worker is morphologically quite similar to T. wilsoni sp. nov. and T. balaclava sp. nov., differing primarily in the conformation of the clypeus, coloration, and sculptural details. The gyne differs from these two species by the concave anterior margin of the postpetiole in dorsal view.

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 137 Temnothorax bahoruco sp. nov. (A-C) Holotype worker (CASENT0758817). (A) Full-face view. (B) Profile view. (C) Dorsal view.(D-F) Paratype gyne (MCZENT00521421).(D) Full-face view. (E) Profile view. (F) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-137