Temnothorax terraztecus, 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 : 417-421

Temnothorax terraztecus sp. nov.

Distribution: Fig. 153J ; worker: Fig. 164 .

Type material examined: Holotype worker: MEXICO: Chiapas: Nahá, 16.94884 ° N 91.59484 ° W ± 50 m, 930 m, 8 June 2008, LLAMA Wa-A-07-2-28, mesophyll forest, ex sifted leaf litter, 1 worker ( CASENT0868966 ) [ CASC].

Paratype workers: same data as holotype, 1 worker (CASENT0868965) [ MCZC], 1 worker (CASENT0868824) [ UCDC] .

Non-type material examined: MEXICO: Chiapas: Nahá , 16.94881 ° N 91.59466 ° W 930 m, 8 June 2008, LLAMA Wa-A-07-2-24, mesophyll forest, ex sifted leaf litter, 1 worker ( JTLC000014496 ) [ USNM] .

HONDURAS: Cortés: PN Cusuco, 15.48754 ° N 88.23678 ° W ± 60 m, 1,220 m, 31 May 2010, LLAMA Wm-C-06-2-03, mesophyll forest, ex sifted leaf litter, 1 worker (CASENT0868823) [ UCDC] .

Geographic range: Low-to-mid elevations, southern Mexico to Honduras ( Fig. 153J ).

Worker diagnosis: Temnothorax terraztecus sp. nov. can be separated from all other species in the salvini clade by the following character combination: smaller species: WL <1.17 mm; dorsum of mesosoma arched in profile view; metanotal groove not impressed; propodeum not strongly depressed below the level of the promesonotum; propodeal spines present and about as long as, or slightly longer than, the propodeal declivity; subpetiolar tooth acutely spiniform and shorter than the setae that arises from the peduncle directly above; petiolar node strongly squamiform: in dorsal view, petiolar node greater than 1.6 times as broad as caudal cylinder; dorsum of head predominantly areolate, with weak rugae; dorsum of petiolar node, postpetiole and entire first gastral tergite smooth and shining; setae on head, mesosoma, legs, waist segments and gaster erect to suberect, long, abundant and tapering; integument predominantly yellow to testaceous.

Similar species: Fellow members of the salvini group. Temnothorax terraztecus sp. nov. can be separated from other members of the salvini group by the arched dorsal profile of the mesosoma in profile view (flat to slightly sinuate in all other salvini group members); squamiform petiolar node (petiolar node less than or equal to 1.5 times as broad as the caudal cylinder in T. longinoi sp. nov., T. quetzal sp. nov., T. fortispinosus sp. nov., T. parvidentatus sp. nov., and T. salvini ); yellow to testaceous integument ( T. longinoi sp. nov., T. longicaulis stat. nov., nom. nov., T. quetzal sp. nov., T. fortispinosus sp. nov., T. parvidentatus sp. nov., and T. salvini are variously colored, but never uniformly yellow); smooth dorsum of the petiolar node, postpetiole, and gaster (sculptured in T. aztecoides sp. nov.); relatively small subpetiolar tooth (longer than the setae that arises directly above it in T. aztecus and T. paraztecus sp. nov.); short propodeal spines (longer than the propodeal declivity in T. aztecoides sp. nov.).

Worker measurements & indices (n = 5): SL = 0.704 –0.767 (0.748); FRS = 0.213 –0.242 (0.226); CW = 0.715 –0.845 (0.784); CWb = 0.637 –0.733 (0.694); PoOC = 0.280 –0.331 (0.309); CL = 0.721 –0.819 (0.777); EL = 0.180 –0.201 (0.193); EW = 0.120 –0.140 (0.126); MD = 0.163 –0.198 (0.181); WL = 0.926 –1.111 (1.029); SPST = 0.284 –0.385 (0.323); MPST = 0.276 –0.323 (0.303); PEL = 0.373 –0.429 (0.404); NOL = 0.225 –0.255 (0.245); NOH = 0.147 –0.174 (0.160); PEH = 0.251 –0.279 (0.270); PPL = 0.176 –0.206 (0.197); PW = 0.468 –0.535 (0.505); SBPA = 0.190 –0.233 (0.214); SPTI = 0.231 –0.275 (0.258); PEW = 0.137 –0.159 (0.151); PNW = 0.235 –0.297 (0.263); PPW = 0.233 –0.261 (0.248); HFL = 0.752 –0.884 (0.810); HFWmax = 0.166 –0.189 (0.180); HFWmin = 0.057 –0.064 (0.061); CS = 0.998 –1.143 (1.083); ES = 0.240 –0.271 (0.256); SI = 105–111 (108); OI = 23–24 (24); CI = 88–91 (89); WLI = 145–152 (148); SBI = 29–33 (31); PSI = 30–35 (31); PWI = 160–170 (165); PLI = 198–213 (206); NI = 147–158 (153); PNWI = 167–188 (174); NLI = 59–62 (61); FI = 272–316 (298);

Worker description: In full-face view, head subquadrate, longer than broad (CI 88–91). Mandibles finely striate but shining and armed with five teeth: the apical-most well developed and acute, followed by a less developed preapical tooth and three equally developed smaller teeth. Anterior clypeal margin weakly convex medially. Antennal scapes very long: when fully retracted, surpassing the posterior margin of the head capsule by about three times the maximum width of the antennal scape (SI 105–111). Antennae 12-segmented; antennal club of composed 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 strongly protruding past the lateral margins of the head capsule. Lateral margin of head convex, forming a continuous arc from the mandibular insertions to the posterior margin of the head. Posterior head margin flat but rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 23–24), with 17 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a ~110 ° angle. Anterior face of pronotum evenly rounding into dorsal face. Dorsum of mesosoma evenly arched from where it joins the anterior face of the pronotum to the propodeal spines. Promesonotal suture extending from the posterior margin of the procoxal insertion only to the mesothoracic spiracle, which is moderately 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 weakly developed, directed posterolaterally, and separated from the propodeal declivity by about five spiracle diameters. Propodeal spines moderately well developed (PSI 30–35), about as long as or slightly longer than the propodeal declivity, tapering evenly from the base, acute, and straight. Propodeal declivity weakly concave, forming a rounded ~110 ° angle with the base of the propodeal spines. Propodeal lobes rounded and weakly developed. Metapleural gland bulla small, extending from the metacoxal insertion to a little more than half of the way to the propodeal spiracle. Petiole long (PLI 198–213), without tubercles anterodorsally. Subpetiolar process in the form of a small, spiniform, acute tooth; ventral margin of petiole weakly concave posterior to it but bulging slightly medially. Petiolar peduncle very long: comprising about two thirds of the total petiole length. Petiolar node rounded-squamiform: transition between peduncle and node marked by a rounded angle of ~120 °; anterior face rounding evenly into the posterior face, the dorsal margin evenly convex; posterior face forms a ~100 ° angle with the caudal cylinder. Postpetiole evenly rounded anterodorsally, bulging before flattening posterodorsally; concave ventrally.

In dorsal view, humeri developed and distinct: evenly rounded and slightly wider than 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. Promesonotal suture visible as a slight disruption in the ground sculpture. Metanotal groove not apparent. Propodeal spines broadly approximated basally and evenly diverging, their apices separated from each other by about their length, the negative space between them “U” shaped. Petiolar peduncle with spiracles slightly protruding past the lateral margins, but not noticeably constricted anterior to them. Petiolar node, when viewed posterodorsally, trapezoidal: much broader apically than basally; apical margin slightly emarginate medially; node broader than the peduncle and the caudal cylinder. Postpetiole narrow (PWI 160–170) and campaniform. Anterior margin of the postpetiole convex, evenly rounding into the lateral margins, which bulge slightly anteriorly, are weakly constricted medially, then diverge slightly again to the angulate posterior corners; posterior margin flat. Metafemur moderately to strongly incrassate (FI 272–316).

Sculpture: median clypeal carina present, extending posteriorly to the frontal triangle, and flanked on either side by multiple slightly weaker carinae. Lateral clypeal lobes with additional, weaker carinae; ground sculpture smooth. Antennal scapes areolate-costulate. Cephalic dorsum areolate with weak overlying rugose sculpture; fine concentric costulae surrounding the antennal insertions. Lateral surfaces of head sculptured similarly to the dorsum, but weak rugae forming whorls around the compound eyes. Ventral surface of head smooth and shining. Pronotal neck areolate. Lateral surfaces of the mesosoma densely rugose, becoming weaker between the propodeal spiracle and the base of the propodeal spine. Propodeal declivity weakly areolate, with weak strigulae. Dorsal surface of mesosoma sculptured similarly to the cephalic dorsum. Femora shining through weak areolate sculpture. Petiole weakly areolate on all surfaces, but sculpture becoming smooth and shining on the node. Postpetiole smooth and shining. First gastral tergite smooth and shining, with weak spectral iridescence. First gastral sternite smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with long, suberect pilosity. Dorsum of the head, pronotum, waist segments, and gaster with abundant, erect, tapering, flexuous setae, the longest of which are about one and a half times the length of the compound eye and are directed toward the midline of the body. The head bears>80, mesosoma>80, petiole ~32, postpetiole ~40, and first gastral tergite>80 setae. Pubescence present over the entire body, which is nearly as long as the setae.

Color: predominantly yellow to testaceous; antennal funiculus, tibiae, and first tarsomere testaceous.

Etymology: Behavioral and morphological, from Latin ‘terra-’ (=earth) + ‘aztecus’, in reference to the superficial similarity between this species and Temnothorax aztecus and the circumstances of collection.

Comments: Temnothorax terraztecus sp. nov. is known from several collections made from low-to-mid elevation wet forests in Chiapas, Mexico and Cortés, Honduras. This species is only known from leaf litter extracts, despite collections of other members of the salvini group being collected sympatrically from beating vegetation or arboreal nest collections. Temnothorax terraztecus sp. nov. may represent the only known non-arboreally nesting member of the salvini group.

Figures

Figure 153 Geographical and elevational distribution of the salvini group. (A) Temnothorax aztecoides sp. nov. (B) T. aztecus (C) T. fortispinosus sp. nov. (D) T. longicaulis stat. nov., nom. nov. (E) T. longinoi sp. nov. (F) T. paraztecus sp. nov. (G) T. parvidentatus sp. nov. (H) T. quetzal sp. nov. (I) T. salvini (J) T. terraztecus 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-153

Figure 164 Temnothorax terraztecus sp. nov. holotype worker (CASENT0868966). (A) Profile view. (B) Full-face view. (C) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-164