Temnothorax paraztecus, 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 : 397-400

Temnothorax paraztecus sp. nov.

Distribution: Fig. 153F ; worker & ergatogyne: Fig. 160 .

Temnothorax salvini grp 7, Prebus, 2021: 12 . In phylogeny.

Type material examined: Holotype worker: NICARAGUA: Jinotega: Parque Nacional Cerro Saslaya , 13.76880 ° N 85.02107 ° W ± 100 m, 1,110 m, 15 May 2011, LLAMA#Go-D- 03-3-03, ridgetop cloud forest, beating vegetation ( CASENT0629030 ) [ CASC].

Paratype worker: same data as holotype, 1 worker (CASENT0758802) [ UCDC] 1 worker (CASENT0629031) [ MCZC] .

Non-type material examined: GUATEMALA: Zacapa: 2 km SE La Unión , 14.94378 ° N 89.27747 ° W ± 104 m, 1,540 m, 13 May 2009, LLAMA#Go-B-03-1-01, cloud forest, beating vegetation, 1 ergatogyne (CASENT0614500) [ JTLC] 1 worker (CASENT0614499) [ UCDC].

HONDURAS: Comayagua: PN Cerro Azul Meambar, 14.87096 ° N 87.89920 ° W ± 20 m, 1,120 m, 20 May 2010, LLAMA#Wa-C-04-1-30, ridgetop cloud forest, ex sifted leaf litter, 1 worker (CASENT0617083) [ JTLC] .

MEXICO: Chiapas: Nahá , 16.96291 ° N 91.59335 ° W ± 300 m, 985 m, 10 June 2008, LLAMA#Go-A-07-1-02, mesophyll forest, beating vegetation, 1 worker (CASENT0608774) [ JTLC] .

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

Worker diagnosis: Temnothorax paraztecus 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 weakly sinuate; metanotal groove not impressed; propodeum not strongly depressed below the level of the promesonotum; propodeal spines shorter than the propodeal declivity; subpetiolar tooth acutely spiniform and equal to or longer than the setae that arise from the peduncle directly above; petiolar node strongly squamiform: in dorsal view, petiolar node greater than or equal to 1.7 times as broad as caudal cylinder; dorsum of head rugose-costate; 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.

Similar species: Fellow members of the salvini group. Temnothorax paraztecus sp. nov. can be separated from other members of the salvini group by the strongly 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 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 (lightly sculptured in T. aztecoides sp. nov.), relatively large subpetiolar tooth (shorter than the setae that arises directly above it in T. aztecoides sp. nov.), and short propodeal spines (longer than the propodeal declivity in T. aztecus ).

Worker measurements & indices (n = 4): SL = 0.715 -0.758 (0.736); FRS = 0.233 –0.256 (0.242); CW = 0.786 –0.845 (0.823); CWb = 0.690 –0.754 (0.728); PoOC = 0.302 –0.323 (0.314); CL = 0.787 –0.831 (0.811); EL = 0.187 –0.205 (0.196); EW = 0.133 –0.146 (0.139); MD = 0.198 –0.218 (0.204); WL = 1.078–1.15 (1.107); SPST = 0.285 –0.349 (0.311); MPST = 0.302 –0.319 (0.312); PEL = 0.413 –0.447 (0.428); NOL = 0.234 –0.271 (0.256); NOH = 0.128 –0.159 (0.145); PEH = 0.248 –0.294 (0.270); PPL = 0.189 –0.229 (0.211); PPH = 0.238 –0.290 (0.264); PW = 0.511 –0.529 (0.523); SBPA = 0.208 –0.239 (0.229); SPTI = 0.218 –0.292 (0.253); PEW = 0.156 –0.179 (0.171); PNW = 0.285 –0.308 (0.300); PPW = 0.247 –0.276 (0.265); HFL = 0.822 –0.863 (0.836); HFWmax = 0.190 –0.206 (0.196); HFWmin = 0.059 –0.067 (0.064); CS = 1.084 –1.170 (1.133); ES = 0.257 –0.273 (0.265); SI = 100–104 (101); OI = 22–24 (23); CI = 87–93 (90); WLI = 145–159 (152); SBI = 30–33 (31); PSI = 26–30 (28); PWI = 152–158 (155); PLI = 186–219 (205); NI = 101–183 (156); PNWI = 172–183 (175); NLI = 56–64 (60); FI = 292–322 (305).

Worker description: In full-face view, head subquadrate, longer than broad (CI 87–93). 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. Antennal scapes very long: when fully retracted, surpassing the posterior margin of the head capsule by about two times the maximum width of the antennal scape (SI 100–104). Antennae 12-segmented; antennal club of composed of three segments, with the apical-most segment about one and a half times as long as the preceding two in combination. Frontal carinae moderately long: extending past the antennal toruli by about two and a half times the maximum width of the antennal scape. Compound eyes protruding past the lateral margins of the head capsule. Lateral margin of head weakly convex, forming a continuous arc from the mandibular insertions to the posterior margin of the head. Posterior head margin weakly concave medially but rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 22–24), with 14 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a ~120 ° angle. Promesonotum weakly convex, with the remainder of the mesosoma weakly sinuate; metanotal groove faintly impressed; propodeum weakly convex to the base of the propodeal spines. Promesonotal suture extending from the posterior margin of the procoxal insertion 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 the poorly developed metathoracic spiracle, which is nearly indistinguishable against the ground sculpture; continuing dorsally as a weak impression. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about four spiracle diameters. Propodeal spines moderately well developed, but short (PSI 26–30), about three quarters as long as the propodeal declivity, weakly upturned, and acute. Propodeal declivity flat, forming a rounded ~120 ° angle with the base of the propodeal spines. Propodeal lobes rounded and weakly developed. Metapleural gland bulla moderately large, extending from the metacoxal insertion two thirds of the way to the propodeal spiracle. Petiole moderately long (PLI 186–219), without tubercles anterodorsally. Subpetiolar process in the form of a small, acute tooth; ventral margin of petiole weakly bulging posterior to it. Petiolar peduncle moderately long: comprising about half the total length of the petiole. Petiolar node erect and narrowly rounded dorsally; squamiform: transition between peduncle and node marked by a rounded angle of ~130 °; anterior face forming a rounded ~60 ° angle with the posterior face; 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 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 weakly impressed and visible as a disruption in the ground sculpture. Propodeal spines narrowly approximated basally and parallel to each other apically, their apices separated from each other by about their length, the negative space between them “U” shaped. Petiolar peduncle with spiracles weakly protruding past the lateral margins, but not noticeably constricted anterior to them. Petiolar node, when viewed posterodorsally, trapezoidal: broader apically than basally; node broader than the peduncle and the caudal cylinder. Postpetiole narrow (PWI 152–158) and campaniform. Anterior margin of the postpetiole weakly convex and evenly rounds into the lateral margins; lateral margins parallel to each other but slightly bulging anteriorly; posterior corners narrowly rounded; posterior margin broadly concave. Metafemur strongly incrassate (FI 292–322).

Sculpture: median clypeal carina present, extending posteriorly nearly to the frontal triangle, and flanked on either side by three slightly weaker carinae. Lateral clypeal lobes with additional, weaker carinae; ground sculpture weakly areolate. Antennal scapes finely areolate. Cephalic dorsum densely areolate, with rugose-costate sculpture overlying the ground sculpture; fine concentric costulae surrounding antennal bases. Lateral surfaces of head sculptured similarly to the dorsum but becoming coarser between the compound eye and the mandibular insertion. Ventral surface of head shining, with weaker costulae. Pronotal neck areolate. Anterior face of pronotum weakly areolate-strigulate; lateral face shining through weakly areolate sculpture, with rugose sculpture on the anterior half, becoming costate on the posterior half. Lateral face of propodeum, meso- and metapleurae with coarsely rugose sculpture over densely areolate sculpture. Propodeal declivity with fine strigulae. Dorsal surface of mesosoma areolate, with costate sculpture overlying the ground sculpture; costae on pronotum concentric anteriorly; propodeum rugose. Femora smooth and shining, but basal quarter finely areolate. Petiole shining through weak areolate sculpture ventrally and on the dorsal surface of the peduncle, otherwise smooth and shining. Postpetiole predominantly smooth and shining, with weak areolate sculpture on the ventrolateral faces and posterior quarter dorsally. First gastral tergite and sternite smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with long, subdecumbent pilosity. Dorsum of the head, pronotum, waist segments, and gaster with abundant, suberect, 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 ~40, mesosoma ~40, petiole ~10, postpetiole ~10, and first gastral tergite ~80 setae. Pubescence present over the entire body, which is nearly as long as the setae.

Color: head and mesosoma predominantly testaceous yellow. Antennal funiculus, masticatory margin of mandibles, apex of femora, tibiae, and base of basalmost tarsi testaceous.

Gyne: Unknown, but see comments below for discussion of ergatogyne.

Male: Unknown.

Etymology: Systematic, from the Ancient Greek ‘para’ (= alongside) and ‘aztecus’, in reference to the phylogenetic position of this species as sister to Temnothorax aztecus .

Comments: Temnothorax paraztecus sp. nov. inhabits cloud forest habitats in Mesoamerica south of the Isthmus of Tehuantepec and north of the Nicaraguan depression. Little is known about its biology, but it forages arboreally, having been collected several times by beating vegetation. The closest relative of T. paraztecus sp. nov. is the morphologically similar T. aztecus , with which it shared a common ancestor a little more than 7 Ma ( Prebus, 2021). Temnothorax paraztecus sp. nov. and T. aztecus also overlap geographically in the Central American Nucleus, but T. paraztecus sp. nov., similar to T. aztecoides sp. nov. inhabits a generally higher elevational range (> 950 m) than T. aztecus ( Figs. 153B & 153F ). Rarely collected, this species apparently inhabits a large present-day geographical range throughout the Central American Nucleus ( Fig. 153F ). Although the gyne of T. paraztecus sp. nov. remains unknown, an ergatogyne was collected in Guatemala, distinguished from workers by the tell-tale expanded tergites on the mesosoma, lack of wing scars, and infuscation on the dorsum of the head marking the positions of where the ocelli would be on a gyne ( Figs. 160D–160F ). Because the material of this species remains scant, I did not perform a dissection of this specimen to determine whether the ergatogyne retained reproductive function (ergatoid gyne) or not (intercaste) ( Peeters, 1991).

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 160 Temnothorax paraztecus sp. nov. (A–C) Holotype worker (CASENT0629030). (A) Full-face view. (B) Profile view. (C) Dorsal view. (D-F) Ergatogyne (CASENT0614500). (D) Full-face view. (E) Profile view. (F) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-160