Temnothorax schwarzi ( Mann, 1920 )

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 : 232-235

Temnothorax schwarzi ( Mann, 1920)

Distribution: Fig. 121E ; gyne: Fig. 126 .

Macromischa (Macromischa) schwarzi Mann, 1920: 415 . Holotype gyne. Cayamas , Cuba.

Leptothorax schwarzi (Mann) : Baroni Urbani, 1978: 497. Worker described. First combination in Leptothorax .

Temnothorax schwarzi (Mann) : Bolton, 2003: 272. First combination in Temnothorax .

Type material examined: Holotype gyne: CUBA: Artemisia: Cayamas, [no collection date], E.A. Schwarz, USNM Type No. 56181, 1 dealate gyne ( USNMENT00532012 ) [ USNM].

Geographic range: Cuba (Artemisia) ( Fig. 121E ).

Worker Diagnosis: Mann described this species from a single dealate gyne, collected in the present-day Cuban province of Mayabeque. Subsequently, Baroni Urbani described workers of Temnothorax schwarzi from several localities in the adjacent Pinar del Rio province in his 1978 revision, based on details of the petiolar node and microsculpture. However, workers and gynes of this species have not yet been recorded from a single nest collection, so there remains some doubt as to how the holotype and Baroni Urbani’ s T. schwarzi are related. For the purposes of diagnosis, I refer to Baroni Urbani’ s concept of the workers: among the species closely related to Temnothorax pastinifer , only the workers of T. schwarzi have the combination of smooth integument on the dorsum of the head and a strongly squamiform petiolar node than overhangs the petiolar peduncle anteriorly. This species may be confused with T. rutabulafer sp. nov., but the latter has a flat to weakly emarginate anterior margin of the clypeus, and densely sculptured head and mesosoma.

Worker: See Baroni Urbani (1978).

Gyne measurements & indices (n = 1): SL = 0.680; FRS = 0.246; CW = 0.870; CWb = 0.814; PoOC = 0.297; CL = 0.780; EL = 0.215; EW = 0.161; MD = 0.183; WL = 1.265; SPST = 0.348; MPST = 0.329; PEL = 0.446; NOL = 0.196; NOH = 0.217; PEH = 0.345; PPL = 0.199; PPH = 0.320; PW = 0.782; SBPA = 0.379; SPTI = 0.456; PEW = 0.200; PNW = 0.328; PPW = 0.509; HFL = 0.731; HFWmax = 0.180; HFWmin = 0.070; CS = 1.204; ES = 0.296; SI = 84; OI = 25; CI = 104; WLI = 155; SBI = 47; PSI = 28; PWI = 255; PLI = 224; NI = 90; PNWI = 164; NLI = 44; FI = 257.

Gyne description: In full-face view, head subquadrate, slightly broader than long (CI 104). Mandibles densely 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 emarginated medially. Antennal scapes very long: when fully retracted, surpassing the posterior margin of the head capsule by about one and a half times the maximum width of the scape (SI 84). Antennae 12-segmented; antennal club composed of three segments, with the apical-most segment 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 evenly convex, converging from below the compound eyes to the mandibular insertions. Posterior head margin flat, rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 25), with 17 ommatidia in longest row. Mesoscutum rounded evenly anteriorly, covering the dorsal surface of the pronotum, and flat dorsally. Mesoscutellum slightly higher than the level of 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 four spiracle diameters. Propodeal spines stout, well developed, and moderately long (PSI 28), about as long as the propodeal declivity, tapering evenly from the base, directed posteriorly, weakly downcurved, 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, but with a slightly angulate dorsal flange. Metapleural gland bulla small, extending from the metacoxal insertion halfway to the propodeal spiracle. Petiole long (PLI 224), without tubercles anterodorsally. Subpetiolar process in the form of a small, very acute tooth, ventral margin of the petiole bulging very weakly posterior to the process. Petiolar peduncle very long: petiolar node comprising about a third of the petiolar dorsum. Petiolar node squamiform: transition between peduncle and node abrupt: marked by a rounded angle of ~110 °; anterior face of the node is straight and does not overtop the peduncle; anterior face forming a ~90 ° angle with the very short dorsal face, which rounds evenly into the convex posterior face. Postpetiole with a flat anterior face, which rounds evenly into the flat dorsal face; ventral surface concave.

In dorsal view, mesoscutum covering pronotum anteriorly, but humeri visible laterally as rounded sclerites. Propodeal spines broadly approximated basally and evenly diverging along their entire length, their apices separated from each other by about two times their length. Petiolar peduncle with spiracles strongly protruding past the lateral margins. Petiolar node, when viewed posterodorsally, roughly trapezoidal: widest apically, tapering to the caudal cylinder, and with the flat dorsal margin weakly emarginated. Broadest part of the petiolar node much wider than the peduncle and the caudal cylinder. Postpetiole very broad (PWI 255), strongly anteroposteriorly compressed, and subquadrate. Postpetiole articulates with most of the anterior margin of the gaster, but leaves 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 parallel to the angulate posterior corners; posterior margin broadly concave. Metafemur moderately incrassate (FI 257).

Sculpture: median clypeal carina present, extending from the anterior margin to the level of the antennal toruli and flanked on either side by additional less distinct carinae; lateral margins of median clypeal lobe with two carinae that are as strong as the medial carina. Lateral clypeal lobes with additional weaker carinae; ground sculpture weakly areolate and shining. Antennal scapes weakly areolate. Cephalic dorsum weakly costulate and shining, with a median sulcus extending from the frontal triangle nearly to the median ocellus. Lateral surfaces of head with stronger costulate sculpture, becoming rugose between the compound eye and the mandibular insertion. Ventral surface of head with weakly costulate. Pronotal neck areolate. Lateral face of the pronotum shining, with very weak areolate-costulate ground sculpture. Anterior third of katepisternum smooth and shining, transitioning into weak areolate-costulate sculpture posteriorly. Anepisternum smooth and shining. Mesopleuron costulate. Propodeum smooth and shining. Mesoscutum predominantly costulate, surrounding a smooth and shining anteromedial patch; smooth and shining patches laterally. Mesoscutellum smooth and shining medially, surrounded by weak areolae. Femora smooth and shining, with traces of weak areolate sculpture distally. Petiole with weak areolate sculpture ventrally, otherwise smooth and shining. Postpetiole shining through weak areolate sculpture anteriorly, with stronger areolate sculpture laterally and dorsally. Gaster predominantly smooth and shining, but first gastral tergite and sternite weakly coriarious.

Setae: antennal scapes and funiculi with short, decumbent pilosity, with several longer setae apically. Dorsum of the head, pronotum, waist segments, and gaster with very sparse, erect, blunt-tipped setae, the longest of which are about half the width of the compound eye. The head bears ~6, mesosoma ~10 restricted to the mesoscutum, petiole 0, postpetiole ~4, and first gastral tergite ~32 setae. Short, sparse pubescence present over the entire body.

Color: nearly uniformly ferruginous red, with slightly darker longitudinal strips on the mesoscutum. Gaster slightly darker than the rest of the body.

Male: Unknown.

Etymology: Patronym, after the collector of the holotype gyne, E.A. Schwarz.

Comments: Temnothorax schwarzi is known only from low lying coastal areas in western Cuba. The holotype gyne was collected in Cayería las Cayamas, a small peninsula in the Gulf of Batabano. The workers of T. schwarzi described by Baroni Urbani were collected from the Guanahacabibes peninsula and two other localities in the province of Pinar del Rio. This species, like other members of the pastinifer group, appears to be tolerant of littoral habitats. While this species is undoubtedly closely related to T. pastinifer , the association of workers and gynes has not yet been definitively made. Although I tend to agree with Baroni Urbani (1978) opinion that the specimens mentioned above are conspecific, an inventory of Cuban species has not been made for several decades. I suspect that there may be a trove of species yet to be described from the island, especially in museum collections, and in the leaf litter of any remnant low elevation forest.

Figures

Figure 121 Geographical and elevational distribution of the pastinifer group. (A) Temnothorax androsanus (B) T. nigricans (C) T. pastinifer (D) T. rutabulafer sp. nov. (E) T. schwarzi. 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-121

Figure 126 Temnothorax schwarzi holotype gyne (USNMENT00532012). (A) Profile view. (B) Fullface view. (C) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-126