Temnothorax salvini

Believed to be an arboreal nester.

Identification
Prebus (2021) – A member of the salvini group of the Temnothorax salvini clade. Temnothorax salvini can be separated from all other species in the salvini clade by the following character combination: 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 small and triangular: shorter than the setae that arises from the peduncle directly above; petiolar node very weakly squamiform: in dorsal view, petiolar node more than or equal to 1 time as broad as caudal cylinder, but less than or equal to 1.5 times as broad; setae on head, mesosoma, legs, waist segments and gaster erect to suberect, moderately long, abundant and tapering; head and mesosoma predominantly dark brown, nearly black; antennae, mandibles, promesonotal suture, legs, dorsum of waist segments, and distal margins of gastral sclerites testaceous; venter of waist segments, basal margins of gastral sclerites, and sting light yellow.

Similar species: Fellow members of the salvini group. Temnothorax salvini can be separated from other members of the salvini group by the very weakly squamiform petiolar node (petiolar node more than or equal to 1.6 times as broad as the caudal cylinder in Temnothorax aztecus, Temnothorax aztecoides, Temnothorax longicaulis and Temnothorax paraztecus), relatively small subpetiolar tooth (longer than the setae that arises directly above it in Temnothorax longinoi), short propodeal spines (longer than the propodeal declivity in Temnothorax quetzal).

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica, Costa Rica, Guatemala, Honduras, Mexico, Panama.

Believed to be an arboreal nesting species.

Biology
Prebus (2021) - Temnothorax salvini, as I now recognize it, is known only from a handful of collections made from mid-to-high elevation cloud forest in Costa Rica and Panama. Jack Longino collected nests from under epiphytes on a tree fall, and additional foraging workers have been collected by beating vegetation. The nest collection contained a single dealate queen. Temnothorax salvini is restricted to the southern Central America cordilleras, with its range encompassing the Caribbean and Pacific slopes, with a generally higher elevational range than its sister species Temnothorax longicaulis ( >1,500 m vs. < 1,300 m), which is restricted to the Pacific slope. Temnothorax salvini and T. longicaulis shared a common ancestor around 5 Ma which had dispersed to the southern Central American cordilleras from the Central American Nucleus during a mountain building phase in southern Central America during the Miocene-Pliocene transition (Prebus, 2020). These two species together are closely related to the morphologically similar T. longinoi, which is restricted to the Central American Nucleus. Like its close relatives in the salvini species group, T. salvini likely nests and forages arboreally. There is a completely dark form of T. salvini from Costa Rica.

Nomenclature

 *  salvini. Macromischa salvini Forel, 1899c: 57, pl. 3, fig. 18 (w.) PANAMA. Combination in Leptothorax: Baroni Urbani, 1978b: 494; in Temnothorax: Bolton, 2003: 272. Current subspecies: nominal plus obscurior (unresolved junior homonym).

Worker
Prebus (2021) - (n = 9): SL = 0.801-0.909 (0.866); FRS = 0.258-0.337 (0.308); CW = 0.836-1.031 (0.958); CWb = 0.735-0.930 (0.860); PoOC = 0.349-0.428 (0.390); CL = 0.901-1.067 (1.001); EL = 0.199-0.269 (0.240); EW = 0.152-0.209 (0.172); MD = 0.203-0.281 (0.232); WL = 1.124-1.450 (1.306); SPST = 0.311-0.380 (0.345); MPST = 0.324-0.430 (0.378); PEL = 0.398-0.511 (0.457); NOL = 0.222-0.314 (0.274); NOH = 0.142-0.170 (0.158); PEH = 0.262-0.336 (0.306); PPL = 0.195-0.291 (0.246); PW = 0.487-0.655 (0.599); SBPA = 0.179-0.329 (0.232); SPTI = 0.244-0.401 (0.294); PEW = 0.166-0.232 (0.208); PNW = 0.205-0.297 (0.252); PPW = 0.263-0.368 (0.334); HFL = 0.855-1.062 (0.996); HFWmax = 0.177-0.220 (0.204); HFWmin = 0.062-0.079 (0.070); CS = 1.186-1.452 (1.360); ES = 0.275-0.374 (0.326); SI = 96-109 (101); OI = 23-26 (24); CI = 82-89 (86); WLI = 146-158 (152); SBI = 22-35 (27); PSI = 23-28 (27); PWI = 156-171 (161); PLI = 158-210 (187); NI = 148-196 (174); PNWI = 101-145 (122); NLI = 53-64 (60); FI = 273-344 (291).

In full-face view, head subquadrate, longer than broad (CI 82-89). Mandibles densely 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 emarginated medially. Antennal scapes moderately long: when fully retracted, surpassing the posterior margin of the head capsule by about the maximum width of the antennal scape (SI 96-109). Antennae 12-segmented; antennal club of composed of three segments, with the apical-most segment slightly longer than the preceding two in combination. Lateral margin of head weakly 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. Frontal carinae short: extending past the antennal toruli by about one and a half times the maximum width of the antennal scape. Compound eyes protruding past the lateral margins of the head capsule.

In profile view, compound eyes ovular and moderately large (OI 23-26), with 14 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a ~110° angle. Mesosoma very weakly convex from where it joins the pronotal neck to the weakly impressed metanotal groove; propodeum flat to the base of the propodeal spines. Promesonotal suture extending from the posterior margin of the procoxal insertion to the mesothoracic spiracle, which is well developed, then continuing dorsally as a weak sulcus. 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 faint 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 23-28), about two thirds as long as the propodeal declivity, flared at the base, weakly downcurved, and acute. Propodeal declivity flat, forming a rounded ~120° angle with the base of the propodeal spines. Propodeal lobes rounded and weakly developed, but slightly angulate dorsally. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole moderately long (PLI 158-210), without tubercles anterodorsally. Subpetiolar process in the form of a very small, triangular tooth, which grades evenly into the ventral surface of the petiole posteriorly; ventral margin of petiole weakly bulging posterior to it. Petiolar peduncle short: comprising about a third of the total length of the petiole. Petiolar node erect and narrowly rounded, nearly cuneiform: 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 face, which is evenly convex; dorsal face rounding evenly into the posterior face, which 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. Promesonotal suture visible as a faint sulcus. Metanotal groove weakly impressed and visible as a disruption in the ground sculpture. Propodeal spines broadly approximated basally and weakly diverging apically, their apices separated from each other by about one and a half times their length, the negative space between them "U" shaped. Petiolar peduncle with spiracles 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 156-171) and subquadrate. Anterior margin of the postpetiole flat but evenly rounds into the lateral margins; lateral margins parallel; posterior corners narrowly rounded; posterior margin broadly concave. Metafemur moderately to strongly incrassate (FI 273-344).

Sculpture: median clypeal carina present, extending posteriorly nearly to the frontal triangle, and flanked on either side by two slightly weaker carinae. Lateral clypeal lobes with additional, weaker carinae; ground sculpture smooth and shining. Antennal scapes weakly areolate. Cephalic dorsum weakly areolate, with predominantly rugose-costate sculpture overlying the ground sculpture. Lateral surfaces of head sculptured similarly to the dorsum, but rugae forming whorls around the compound eyes. Ventral surface of head shining, with weaker costulae. Pronotal neck areolate. Anterior face of pronotum coarsely areolate; lateral face coarsely costate. Lateral face of pronotum, meso- and metapleuron coarsely rugose over weak areolate sculpture. Propodeal declivity weakly areolate. Dorsal surface of mesosoma weakly areolate, with costate sculpture overlying the ground sculpture; costae on pronotum concentric anteriorly; rugae on propodeum weaker and transverse. Femora smooth and shining. Petiole shining through very weak areolate sculpture ventrally and on the dorsal surface of the peduncle, otherwise smooth and shining; a weak carina extends longitudinally from the propodeal spiracle to the caudal cylinder. Postpetiole smooth and shining. First gastral tergite and sternite smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with moderately long, subdecumbent pilosity. Dorsum of the head, pronotum, waist segments, and gaster with abundant, suberect, tapering, flexuous setae, the longest of which are slightly longer than the length of the compound eye and are directed toward the midline of the body. The head bears ~40, mesosoma ~42, petiole 4, postpetiole ~18, and first gastral tergite ~84 setae. Pubescence present over the entire body, which is nearly as long as the setae.

Color: head and mesosoma predominantly dark brown, nearly black. Antennae, mandibles, promesonotal suture, legs, dorsum of waist segments, and distal margins of gastral sclerites testaceous. Venter of waist segments, basal margins of gastral sclerites, and sting light yellow.

Queen
Prebus (2021) - (n = 1): SL = 0.892; FRS = 0.333; CW = 1.083; CWb = 0.975; PoOC = 0.410; CL = 1.079; EL = 0.297; EW = 0.208; MD = 0.221; WL = 1.738; SPST = 0.406; MPST = 0.435; PEL = 0.556; NOL = 0.329; NOH = 0.199; PEH = 0.400; PPL = 0.296; PW = 0.925; SBPA = 0.386; SPTI = 0.388; PEW = 0.282; PNW = 0.303; PPW = 0.471; HFL = 1.157; HFWmax = 0.205; HFWmin = 0.07; CS = 1.515; ES = 0.401; SI = 91; OI = 26; CI = 90; WLI = 178; SBI = 40; PSI = 23; PWI = 167; PLI = 188; NI = 165; PNWI = 107; NLI = 59; FI = 293.

In full-face view, head subquadrate, longer than broad (CI 90). Mandibles finely 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 weakly emarginated medially. Antennal scapes moderately long: surpassing the posterior margin of the head capsule by about the maximum width of the antennal scape (SI 91). Antennae 12-segmented; antennal club composed of three segments, with the apical-most segment as long as the preceding two in combination. Frontal carinae short: extending past the antennal toruli by about 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 evenly convex, converging from below the compound eyes to the mandibular insertions. Posterior head margin weakly concave but rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 26), with 20 ommatidia in longest row. Mesoscutum rounded evenly anteriorly, not fully covering the dorsal surface of the pronotum, and weakly convex dorsally. Mesoscutellum slightly depressed below the level of the mesoscutum and weakly convex dorsally. Posterior margin of metanotum extending beyond the posterior margin of the mesoscutum. 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), about as two thirds as long as the propodeal declivity, tapering evenly from the base, directed posteriorly, straight, and acute. Propodeal declivity weakly concave, forming a rounded ~100° angle with the base of the spines. Propodeal lobes rounded and weakly developed, but slightly angulate dorsally. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole moderately long (PLI 188), without tubercles anterodorsally. Subpetiolar process in the form of a minute, blunt tooth, which grades evenly into the ventral margin of the petiole posteriorly. Petiolar peduncle short: comprising about a third of the total petiole length. Petiolar node erect and narrowly rounded, nearly cuneiform: 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 face, which is evenly convex; dorsal face rounding evenly into the posterior face, which forms a ~100° angle with the caudal cylinder. Postpetiole evenly rounded anterodorsally, bulging before flattening posterodorsally; lobed ventrally.

In dorsal view, mesoscutum not fully covering pronotum anteriorly; humeri visible laterally as angulate sclerites. Mesoscutum with a distinctive shape: hexagonal, with anterior margin narrow and weakly convex, lateral margins diverging posteriorly to the wing bases, then converging slightly to the posterior margin, which is broader than the anterior margin. Propodeal spines weakly diverging apically, their apices separated from each other by about twice their length. Petiolar peduncle with spiracles protruding past the lateral margins, but not noticeably constricted anterior to them. Petiolar node, when viewed posterodorsally, trapezoidal: broader apically than basally; node slightly broader than the peduncle and the caudal cylinder. Postpetiole narrow (PWI 167) and campaniform. Anterior margin of postpetiole nearly flat, with corners evenly rounding into the lateral margins, which diverge slightly to the angulate posterior corners; posterior margin flat. Metafemur moderately incrassate (FI 293).

Sculpture: median clypeal carina present, extending from the anterior margin nearly to frontal triangle, and flanked two equally strong carinae. Lateral clypeal lobes with additional weaker carinae; ground sculpture superficially areolate. Antennal scapes weakly areolate. Cephalic dorsum weakly areolate, with rugose-costate sculpture overlying the ground sculpture; antennal insertions surrounded by concentric costulae. Lateral surfaces of head sculptured similarly to the dorsum, but rugae forming whorls around the compound eye, and reticulation becoming stronger between the compound eye and mandibular insertion. Ventral surface of head mostly smooth and shining, with weak costulae. Pronotal neck areolate. Pronotum smooth and shining anteriorly and costate laterally. Anepisternum predominantly smooth and shining, with superficial costae. Katepisternum smooth and shining, with superficial costae that become stronger posteriorly. Metapleuron and lateral face of propodeum with stronger costae. Propodeal declivity strigulate. Mesoscutum with costulae over areolate ground sculpture; a small patch of finely areolate sculpture anteromedially. Mesoscutellum costulate. Metanotum finely areolate. Dorsal face of propodeum coarsely rugose. Femora smooth and shining. Petiole with fine costulae ventrally, and on the dorsal surface of the peduncle; base of node with stronger costulae; apex of node smooth and shining. Postpetiole smooth and shining anteriorly, very finely areolate laterally. First gastral tergite and sternite smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with moderately long, subdecumbent pilosity. Dorsum of the head, pronotum, waist segments, and gaster with abundant, suberect, tapering, flexuous setae, the longest of which are as long as the width of the compound eye. Pubescence present over the entire body, which is nearly as long as the setae.

Color: head and mesosoma predominantly dark brown, nearly black. Antennae, mandibles, promesonotal suture, legs, dorsum of waist segments, and distal margins of gastral sclerites testaceous. Venter of waist segments, basal margins of gastral sclerites, and sting light yellow.

Type Material
Macromischa salvini: Syntype workers. Volcán de Chiriqui, Panama. One syntype worker here designated lectotype.

Lectotype worker: PANAMA: Chiriquí: Volcán de Chiriquí, 1,220-1,830 m, Champion #99-304, leftmost specimen (images of BMNH (E) 1014995, CASENT0901796 examined on antweb.org).

Paralectotype worker: same data as lectotype, 1 worker, severely damaged (images of CASENT0908989 examined on antweb.org).

Etymology
Patronym, presumably in honor of English naturalist Osbert Salvin, who collected in Mesoamerica during the 19 th century.

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1978. Materiali per una revisione dei Leptothorax neotropicali appartenenti al sottogenere Macromischa Roger, n. comb. (Hymenoptera: Formicidae). Entomol. Basil. 3: 395-618.
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Wheeler W. M. 1931. New and little-known ants of the genera Macromischa, Creosomyrmex and Antillaemyrmex. Bulletin of the Museum of Comparative Zoology 72: 1-34.
 * Wheeler W. M. 1937. Ants mostly from the mountains of Cuba. Bulletin of the Museum of Comparative Zoology. 81: 439-465.