Temnothorax wettereri, 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 : 333-337

Temnothorax wettereri sp. nov.

Distribution: Fig. 133N ; worker: Fig. 148 .

Type material examined: Holotype worker: ANTIGUA AND BARBUDA: Barbuda: Gut Road , 4 km W of town, 17.63 ° N 61.783 ° W, 20 m, 11 June 2007, J.K. Wetterer #JKW- 2007-483 ( CASENT0756094 ) [ USNM].

Paratype workers: same data as holotype, 1 worker (CASENT0758675) [ UCDC] 1 worker (CASENT0758818) [ MCZC] .

Geographic range: Barbuda ( Fig. 133N ).

Worker diagnosis: Temnothorax wettereri sp. nov. 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 without standing setae dorsally; propodeal spines slightly longer than the propodeal declivity, directed posterodorsally, and very slightly downcurved; in dorsal view, propodeal spines broadly approximated basally, the negative space between them “U” shaped; hind femora weakly to moderately incrassate; petiolar node rounded dorsally; in dorsal view, apex of petiolar node the same width as or slightly broader than the caudal cylinder of the petiole; postpetiole very broad: greater than 2.4 times the width of the petiole; median clypeal carina obscured by areolate ground sculpture; dorsum of head uniformly areolate; mesosoma bearing less than ten erect setae dorsally; setae on head, mesosoma, waist segments and gaster erect, moderately long, sparse and blunt (never long and tapering); integument uniformly light brown, with the surface of the metapleural gland, posterior margin of the postpetiole, and posterior halves of the gastral sclerites darker brown; mandibles, tibiae, and tarsi pale yellow.

Similar species: Temnothorax agavicola sp. nov., T. albispinus , T. laticrus sp. nov., T. torrei , and members of the pastinifer group. Temnothorax wettereri sp. nov. can be separated from most members of the pastinifer group by the petiolar node, which not squamiform and relatively narrow in dorsal view: 1 to 1.1 times the width of the caudal cylinder of the petiole in T. albispinus versus 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. wettereri sp. nov. from T. laticrus sp. nov. The lack of erect setae on the dorsum of the petiolar node differentiates T. wettereri sp. nov. from all of the above species. The flat to weakly convex posterior margin of the head of T. wettereri sp. nov. 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 (n = 2): SL = 0.476 –0.519 (0.494); FRS = 0.177 –0.186 (0.181); CW = 0.550 –0.578 (0.565); CWb = 0.505 –0.532 (0.519); PoOC = 0.221 –0.247 (0.231); CL = 0.585 –0.619 (0.601); EL = 0.136 –0.145 (0.141); EW = 0.105 –0.109 (0.107); MD = 0.153 –0.162 (0.157); WL = 0.619 –0.646 (0.630); SPST = 0.225 –0.241 (0.234); MPST = 0.190 –0.212 (0.203); PEL = 0.276 –0.295 (0.283); NOL = 0.169 –0.187 (0.179); NOH = 0.104 –0.118 (0.112); PEH = 0.188 –0.206 (0.196); PPL = 0.153 –0.180 (0.167); PPH = 0.193 –0.210 (0.202); PW = 0.334 –0.360 (0.350); SBPA = 0.136 –0.140 (0.138); SPTI = 0.189 –0.204 (0.199); PEW = 0.119 –0.138 (0.130); PNW = 0.135 –0.145 (0.139); PPW = 0.291 –0.326 (0.311); HFL = 0.455 –0.486 (0.470); HFWmax = 0.114 –0.119 (0.117); HFWmin = 0.040 –0.046 (0.043); CS = 0.798 –0.842 (0.820); ES = 0.191 –0.199 (0.195); SI = 93–98 (95); OI = 24; CI = 86–87 (86); WLI = 120–123 (121); SBI = 26–27 (27); PSI = 36–38 (37); PWI = 236–245 (239); PLI = 163–182 (170); NI = 153–163 (159); PNWI = 100–113 (107); NLI = 61–65 (63); FI = 259–285 (275).

Worker description: In full-face view, head subquadrate, longer than broad (CI 86–87). Mandibles striate, weakly shining, and armed with five teeth: the apical-most well developed, followed by a smaller preapical tooth, which is followed by three equally developed smaller teeth. Anterior clypeal margin flat to very slightly concave medially. Antennal scapes moderately long: when fully retracted, extending past the posterior margin of the head capsule by about the maximum width of the antennal scape (SI 93–98). 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 slightly convex, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 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 36–38), about as long as the propodeal declivity, tapering evenly from the base, very slightly downcurved at the apical quarter, and acute. Propodeal declivity weakly concave, forming a rounded ~110 ° 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 163–182), without tubercles anterodorsally; subpetiolar process in the form of a weakly developed, blunt tooth; ventral surface of petiole slightly concave posterior to the process. Petiolar peduncle moderately long: comprising about half 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 and short; dorsal face rounding evenly into the posterior face, which 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 protruding past the rest of the mesosoma; mesothoracic spiracles 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 roughly by their length; negative space between them “U” shaped. Petiolar peduncle with spiracles slightly protruding past the lateral margins. Petiolar node weakly campaniform, with the posterior margins rounded, slightly wider than the peduncle, and evenly grading into the caudal cylinder, which is slightly wider than the node. Postpetiole very broad (PWI 236–245) and campaniform, articulating with the nearly the entire anterior margin of the gaster, leaving rounded angles of the gaster on each side exposed anteriorly. 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 incrassate (FI 259–285).

Sculpture: median clypeal carina present but very weak, extending halfway from the anterior clypeal margin to the frontal triangle before becoming obscured by areolate ground sculpture. Antennal scapes weakly areolate and dull. Cephalic dorsum and lateral surfaces of head densely areolate. Ventral surface of head shining through weaker areolate sculpture. Mesosoma evenly, densely areolate. Femora shining through weak areolate sculpture. Peduncle of petiole smooth and shining ventrally, with shallow areolate sculpture surrounding the base of the petiolar node, which is weakly shining through weak areolate sculpture dorsally. Dorsal surface of postpetiole dull with weak costulae and shallow areolae. Gaster smooth and shining, with very weak spectral iridescence on the first tergite. Surface of the first gastral sternite smooth and shining.

Setae: antennal scapes and funiculi with short, adpressed pilosity. Setae sparse on all body surfaces: dorsum of head with short, erect, blunt-tipped setae, the longest of which are roughly the ½ the width of the compound eye. The head bears ~16, mesosoma ~4, postpetiole ~2, and first gastral tergite ~4 erect 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: uniformly light brown, with the surface of the metapleural gland, posterior margin of the postpetiole, and posterior halves of the gastral sclerites darker brown. Mandibles, tibiae, and tarsi are pale yellow.

Gyne: Unknown.

Male: Unknown.

Etymology: Patronym, in honor of the collector of the type series, James K. Wetterer.

Comments: Temnothorax wettereri sp. nov. is known only from the type series. Barbuda is a low-lying coral limestone island with little topographical variation, supporting primarily tropical scrub vegetation. The climate is tropical marine, with little seasonal temperature variation. The natural history of this species remains unknown but is likely to be similar to other members of the ground and leaf litter nesting pulchellus group.

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 148 Temnothorax wettereri sp. nov. holotype worker (CASENT0756094). (A) Profile view. (B) Full-face view. (C) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-148