Temnothorax misomoschus, 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 : 200-205

Temnothorax misomoschus sp. nov.

Distribution, worker & gyne: Fig. 120 .

Temnothorax mmp12 Prebus, 2017: 8. Phylogeny.

Type material examined: Holotype worker: U.S.A.: Texas: Cameron County: 16 km W Boca Chica, 11 January 1968, R.R. Snelling #1968-8 ( LACMENT323430 , top specimen on pin) [ LACM].

Paratype workers and gyne: same pin as holotype, 2 workers (middle and bottom specimens on pin) ( LACM); same data as holotype, 1 dealate gyne & 2 workers (LACMENT323429) [ LACM] .

Non-type material examined: NICARAGUA: Madriz: 8 km S Somoto , 13.40447 ° N 86.58267 ° W ± 50 m, 1,415 m, 22 April 2011, J. Longino #JTL7384-s, coffee farm, at bait, 1 worker (CASENT0619604) [ UCDC] .

Geographic range: Southern Texas and Nicaragua ( Fig. 120G ).

Worker diagnosis: The following character combination will separate Temnothorax misomoschus sp. nov. from all other species in the salvini clade: mesosoma compact (WLI 128–136); propodeum strongly depressed; propodeal spines longer than the propodeal declivity (PSI 33–38), and downwardly curved; hind femora strongly incrassate; petiolar node subquadrate and leans posteriorly over the caudal cylinder; postpetiole moderately broad; body devoid of erect setae, except for the clypeus and posterior margins of the gastral sclerites; integument medium brown, with tibiae and tarsi testaceous.

Similar species: It is difficult to imagine that this striking species could be confused with any other in Temnothorax , but T. misomoschus sp. nov. vaguely resembles T. subditivus ; the lack of erect setae and the subquadrate petiolar node in T. misomoschus sp. nov. (as opposed to squamiform in T. subditivus ) will distinguish the two.

Worker measurements & indices (n = 6): SL = 0.500 –0.542 (0.515); FRS = 0.213 –1.107 (0.370); CW = 0.655 –0.693 (0.675); CWb = 0.610 –0.645 (0.627); PoOC = 0.251 –0.277 (0.264); CL = 0.686 –0.719 (0.705); EL = 0.161 –0.170 (0.166); EW = 0.120 –0.137 (0.128); MD = 0.148 –0.179 (0.162); WL = 0.793 –0.864 (0.817); SPST = 0.262 –0.322 (0.287); MPST = 0.240 –0.290 (0.260); PEL = 0.338 –0.366 (0.349); NOL = 0.190 –0.232 (0.211); NOH = 0.144 –0.155 (0.151); PEH = 0.237 –0.269 (0.251); PPL = 0.147 –0.178 (0.160); PPH = 0.206 –0.293 (0.234); PW = 0.407 –0.453 (0.423); SBPA = 0.143 –0.180 (0.162); SPTI = 0.226 –0.253 (0.237); PEW = 0.146 –0.167 (0.158); PNW = 0.151 –0.179 (0.166); PPW = 0.269 –0.308 (0.290); HFL = 0.564 –0.681 (0.598); HFWmax = 0.154 –0.172 (0.160); HFWmin = 0.041 –0.049 (0.046); CS = 0.957 –1.005 (0.979); ES = 0.221 –0.238 (0.230); SI = 81–84 (82); OI = 23–24 (23); CI = 86–90 (89); WLI = 128–136 (130); SBI = 23–28 (26); PSI = 33–38 (35); PWI = 174–192 (183); PLI = 199–236 (219); NI = 128–151 (139); PNWI = 99–109 (105); NLI = 55–64 (60); FI = 322–393 (353).

Worker description: In full-face view, head subquadrate, slightly longer than broad (CI 86–90). 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 flat medially. Antennal scapes short: when fully retracted, failing to reach the posterior margin of the head capsule by about two times the maximum width of the scape (SI 81–84). 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 moderately 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 15 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a ~120 ° angle. Mesosoma strongly sinuate: very strongly convex from where it joins the pronotal neck to the propodeum, which is concave and rounds evenly into 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; suture continues dorsally as an indistinct disruption in the ground sculpture. 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 moderately well developed, directed posterolaterally, and separated from the propodeal declivity by about four spiracle diameters. Propodeal spines well developed and long (PSI 33–38), slightly longer than the propodeal declivity, tapering evenly from the base, very strongly downcurved, and acute. Propodeal declivity flat, 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 halfway to the propodeal spiracle. Petiole long (PLI 199–236), without tubercles anterodorsally. Subpetiolar process in the form of a small, triangular tooth; ventral margin of petiole weakly concave posterior to it. Petiolar peduncle moderately long: comprising slightly less than half the length of the petiole. Petiolar node robust and erect, subquadrate: transition between peduncle and node marked by a rounded angle of ~120 °, resulting in a concave anterior node face; anterior face rounding evenly into the dorsal face, which is evenly convex; dorsal face meeting the posterior face at a ~90 ° angle; posterior face which forms a ~85 ° angle with the caudal cylinder, overhanging it. Postpetiole flat anteriorly, bulging anterodorsally before flattening posterodorsally; weakly lobed ventrally.

In dorsal view, humeri developed: evenly rounded and wider than the rest of the mesosoma; mesothoracic spiracles not protruding past the lateral margins of the mesosoma. Promesonotal suture indicated by a disruption in the ground sculpture. Metanotal groove absent: mesonotum and propodeum completely fused and lateral margins converging evenly to the bases of the propodeal spines; propodeal spiracles protruding laterally. Propodeal spines narrowly approximated basally and weakly diverging apically, their apices separated from each other by slightly less than their length, the negative space between them “U” shaped. Petiolar peduncle with spiracles not protruding past the lateral margins; peduncle not noticeably constricted anterior to them. Petiolar node evenly ovular and slightly longitudinally elongate; node the same width as the peduncle, and evenly grading into the caudal cylinder, which is wider than the node. Postpetiole narrow (PWI 174–192) and campaniform, articulating with most of the anterior margin of the gaster, leaving small, angulate margins on each side exposed. Anterior margin of the postpetiole convex and evenly rounds into the lateral margins, which are evenly convex to the posterior corners; posterior margin flat. Metafemur strongly incrassate (FI 322–393).

Sculpture: median clypeal carina present but indistinct from the multiple, equally strong carinae that flank it. Lateral clypeal lobes with additional, weaker carinae; ground sculpture smooth and shining. Antennal scapes areolate-costulate. Cephalic dorsum very finely costulate, with very fine concentric costulae surrounding the antennal insertions. Lateral surfaces of head costulate over areolate sculpture, becoming rugulose between the compound eye and the mandibular insertion. Ventral surface of head weakly, finely areolate-costulate. Pronotal neck strigulate. Lateral surfaces of the mesosoma areolate, but meso- and metapleurae rugulose. Propodeal declivity weakly areolate. Dorsal surface of mesosoma areolate, with fine costulae over the promesonotum. Femora shining, with weak areolate sculpture on the distal third. Petiole and postpetiole shining through weak areolate sculpture, with ventral surface of petiole and anterior face of postpetiole very weakly areolate. Gaster smooth and shining, without spectral iridescence.

Setae: antennal scapes and funiculi with short, decumbent pilosity. Body apparently without erect setae, except for the clypeus, and sporadically on the postpetiole. Short, sparse pubescence present over the entire body.

Color: predominantly medium brown, with tibiae and tarsi testaceous.

Gyne measurements & indices (n = 1): SL = 0.588; FRS = 0.260; CW = 0.860; CWb = 0.754; PoOC = 0.262; CL = 0.780; EL = 0.272; EW = 0.219; MD = 0.145; WL = 1.358; SPST = 0.343; MPST = 0.353; PEL = 0.426; NOL = 0.227; NOH = 0.221; PEH = 0.379; PPL = 0.203; PPH = 0.372; PW = 0.728; SBPA = 0.350; SPTI = 0.342; PEW = 0.215; PNW = 0.265; PPW = 0.404; HFL = 0.769; HFWmax = 0.177; HFWmin = 0.044; CS = 1.144; ES = 0.382; SI = 78; OI = 33; CI = 97; WLI = 180; SBI = 46; PSI = 25; PWI = 188; PLI = 210; NI = 103; PNWI = 123; NLI = 53; FI = 402.

Gyne description: In full-face view, head subquadrate, about as long as broad (CI 97). Mandibles densely, 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 flat medially. Antennal scapes short: when fully retracted, failing to reach the posterior margin of the head capsule by about two times the maximum width of the scape (SI 78). 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 strongly protruding past the lateral margins of the head capsule. Lateral margin of head behind the compound eyes convex; below the compound eyes, lateral margins parallel, then converging to the mandibular insertions. Posterior head margin flat, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and large (OI 33), with 20 ommatidia in longest row. Mesoscutum rounded evenly anteriorly, covering the dorsal surface of the pronotum, and flat dorsally. Mesoscutellum on the same level as the mesoscutum. Posterior margin of metanotum extending slightly past the posterior margin of the mesoscutum. Propodeal spiracle well developed, directed posterolaterally, and separated from the propodeal declivity by about five spiracle diameters. Propodeal spines stout and well developed, but short (PSI 25), about half as long as the propodeal declivity, tapering evenly from the base, directed posteriorly, very weakly downcurved at the tips, and acute. Propodeal declivity straight and flat, forming a rounded ~120 ° 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 long (PLI 210), without tubercles anterodorsally. Subpetiolar process in the form of a small, triangular, very blunt tooth, which grades evenly into the ventral margin of the petiole posteriorly. Petiolar peduncle short: comprising about a third of the length of the petiole. Petiolar node robust and erect, nearly squamiform: transition between peduncle and node indistinct, marked by a rounded angle of ~140 °, resulting in a concave anterior node face; anterior face rounding evenly into the dorsal face, which is moderately convex; dorsal face rounding evenly into the posterior face, which forms a ~90 ° angle with the caudal cylinder. Postpetiole very flat anteriorly, bulging strongly anterodorsally before flattening posterodorsally; ventral surface weakly lobed.

In dorsal view, mesoscutum covering pronotum anteriorly, but humeri visible laterally as slightly angulate sclerites. Propodeal spines weakly diverging apically, their apices separated from each other by about twice their length. Petiolar peduncle with spiracles not protruding past the lateral margins. Petiolar node subquadrate, nearly trapezoidal: flattened anteriorly and posteriorly, with posterior face narrower. Petiolar node slightly wider than the peduncle and caudal cylinder. Postpetiole subquadrate, narrow (PWI 188), and articulating with most of the anterior margin of the gaster, leaving small, angulate margins on each side exposed. Anterior margin of postpetiole flat, with corners marked by rounded angles as it transitions to the lateral margins, which are evenly convex to the posterior corners; posterior margin flat. Metafemur strongly incrassate (FI 402).

Sculpture: median clypeal carina present, but indistinct from the multiple, equally strong carinae that flank it. Lateral clypeal lobes with additional weaker carinae; ground sculpture weakly areolate. Antennal scapes very finely costulate. Cephalic dorsum costulate over fine areolate sculpture; very fine concentric costulae surrounding the antennal insertions. Lateral surfaces of head with areolate-costulate sculpture forming whorls around posterior margin of the compound eye, with rugulose sculpture between the compound eye and the mandibular insertion. Ventral surface of head shining through weak areolate-costulate sculpture. Pronotal neck shining through weak strigulate sculpture. Lateral surfaces of the mesosoma finely longitudinally areolate-costulate, becoming weaker on the mesopleurae. Propodeal declivity shining and weakly areolate. Mesoscutum and mesoscutellum costulate over weak areolate ground sculpture. Femora shining through traces of weak areolate sculpture. Petiole weakly areolate and shining. Postpetiole smooth and shining anteriorly; dorsal surface weakly areolate-strigulate. First gastral tergite smooth and shining, with faint traces of spectral iridescence. First gastral sternite smooth and shining.

Setae: antennal scapes and funiculi with short, decumbent pilosity. Sparse, erect, blunt-tipped setae, on the dorsal surface of the head, mesosoma, postpetiole, and gaster. Short, sparse pubescence present over the entire body.

Color: Predominantly medium brown, with tibiae and tarsi testaceous.

Male: Unknown.

Etymology: Greek, ‘misos’ (= hatred) and ‘moschus’ (= musk). On 30 March 2021 a prototype rocket launched by SpaceX, an aerospace manufacturer and space transportation service founded by Elon Musk, exploded over the Lower Rio Grande Valley National Wildlife Refuge, which encompasses the type locality of Temnothorax misomoschus sp. nov. The explosion resulted in a rain of debris on the wildlife refuge, which is critical habitat for ocelots, migratory bird species, as well as the only known population of the Boca Chica flea beetle, Chaetocnema rileyi .

Comments: Temnothorax misomoschus sp. nov. is known from only a few of collections that span a large range. Roy Snelling collected the type series near Boca Chica, Texas; much later Jack Longino collected several workers at a cookie bait on a coffee farm in northwestern Nicaragua. Most recently Steven Wang collected and photographed a worker of this species found in Goliad, Texas. This species is closely related to the goniops species group, which spans Southern Mexico to Guatemala. Unfortunately, the circumstances of the type collection are unknown, but I suspect that T. misomoschus sp. nov. nests in the soil or the leaf litter, similar to species of the goniops group.

Figures

Figure 120 Temnothorax misomoschus sp. nov. (A–C) Holotype worker (LACMENT323430). (A) Full-face view. (B) Profile view. (C) Dorsal view. (D–F) Paratype gyne (LACMENT323429). (D) Full-face view. (E) Profile view. (F) Dorsal view. (G) Geographical and elevational distribution of specimens examined. Type localities are represented by triangles, non-type localities are represented by circles. Bounding box in inset map shows location of main map. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-120