Temnothorax huehuetenangoi ( Baroni Urbani, 1978 )

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 : 184-187

Temnothorax huehuetenangoi ( Baroni Urbani, 1978)

Worker: Fig. 117 .

Leptothorax huehuetenangoi Baroni Urbani, 1978: 451 , figs. 64, 106. Holotype worker. San de José , Guatemala.

Temnothorax huehuetenangoi (Baroni Urbani) : Bolton, 2003: 271. First combination in Temnothorax .

Type material examined: Holotype worker: GUATEMALA: San de José [intercepted in quarantine, San Francisco, California, U.S.A.], 11 April 1946, SF 20724, 46-5347, ex Odontoglossum bictoniense ( USNMENT00529517 ) [ USNM].

Geographic range: Unknown. Intercepted in quarantine in cargo from Guatemala.

Worker diagnosis: Temnothorax huehuetenangoi can be separated from all other species in the salvini clade by the following character combination: antennal scapes short, failing to reach the posterior margin of the head capsule by about the width of the antennal scape (SI 84); compound eyes small (OI 24); head sculpture smooth and shining; body compact (WLI <140); metanotal groove absent; erect setae present on propodeum; propodeum not strongly depressed; propodeal spines about as long as the propodeal declivity (PSI 32), directed posterodorsally, and straight; propodeal spines broadly approximated in dorsal view (SBI 30); hind femora moderately incrassate (FI 298); petiolar node erect and subquadrate, not overhanging the caudal cylinder in profile view; petiolar node compact, not elongate (NI 145); petiolar node barely broader than caudal cylinder in dorsal view (PNWI 117); postpetiole moderately broad (150 <PWI <220); antennal scapes with short, decumbent pilosity; setae on head, mesosoma, waist segments and gaster erect, short, sparse and blunt (never long and tapering); integument bicolored: antennae, mandibles, mesosoma, legs, and waist segments mostly yellow, with head capsule, meso- and metapleurae, and gaster dark testaceous brown.

Similar species: Temnothorax casanovai sp. nov., T. leucacanthoides sp. nov., T. leucacanthus , T. ocarinae , T. parvidentatus sp. nov., T. tenuisculptus , species of the goniops and pulchellus groups. Temnothorax huehuetenangoi differs from all of the above species, except for T. tenuisculptus , T. xincai sp. nov. of the goniops group, and some members of the pulchellus group (e.g., T. agavicola sp. nov., T. albispinus , T. laticrus sp. nov., T. torrei , and T. wettereri sp. nov.) by the smooth and shining sculpture of the head. Additionally, the structure of the petiolar node, which is erect in T. huehuetenangoi , will distinguish it from T. leucacanthus and T. leucacanthoides sp. nov., in which the petiolar node leans posteriorly over the caudal cylinder. The short, sparse, blunt setae separates T. huehuetenangoi from T. casanovai sp. nov. Temnothorax ocarinae can differentiated by the relatively long petiolar node (NI ~ 194 vs. 145 in T. huehuetenangoi ). The weakly incrassate femora distinguishes T. huehuetenangoi from many of the species above, including T. tenuisculptus , T. casanovai sp. nov., and T. ocarinae . The moderately broad postpetiole (in dorsal view) will separate T. huehuetenangoi from all members of the pulchellus group (PWI <210). Temnothorax huehuetenangoi can be distinguished from other members of the goniops group by the bicolored integument (yellow in T. goniops , and predominantly dark brown in T. ixili , T. achii sp. nov., and T. xincai sp. nov.), the relatively long, spiniform propodeal spines (short and dentate in T. ixili , T. achii sp. nov., and T. xincai sp. nov.), and the smooth and shining sculpture of the head (areolate to rugulose in the rest of the goniops group, except T. xincai sp. nov.).

Worker measurements & indices (n = 1): SL = 0.392; FRS = 0.149; CW = 0.516; CWb = 0.465; PoOC = 0.206; CL = 0.538; EL = 0.130; EW = 0.094; MD = 0.110; WL = 0.633; SPST = 0.202; MPST = 0.211; PEL = 0.269; NOL = 0.161; NOH = 0.111; PEH = 0.182; PPL = 0.154; PPH = 0.176; PW = 0.332; SBPA = 0.141; SPTI = 0.207; PEW = 0.127; PNW = 0.148; PPW = 0.261; HFL = 0.420; HFWmax = 0.119; HFWmin = 0.040; CS = 0.734; ES = 0.177; SI = 84; OI = 24; CI = 86; WLI = 136; SBI = 30; PSI = 32; PWI = 206; PLI = 175; NI = 145; PNWI = 117; NLI = 60; FI = 298.

Worker description: In full-face view, head subquadrate, longer than broad (CI 86). 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 evenly convex medially Antennal scapes short: when fully retracted, failing to reach the posterior margin of the head capsule by about the maximum width of the scape (SI 84). Antennae 12-segmented; antennal club of composed of three segments, with the apical-most segment longer than the preceding two in combination. Frontal carinae long, extending past the antennal toruli by about three 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, longitudinally elongate, and moderately large (OI 24), with 10 ommatidia in longest row. Pronotal declivity indistinct, neck and anterior face of pronotum forming a ~120 ° angle. Mesosoma convex from where it joins the pronotal neck to the propodeal spines, but propodeum slightly flattened, giving the dorsal margin a weakly sinuate shape. 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 well developed, directed posterolaterally, and separated from the propodeal declivity by about three spiracle diameters. Propodeal spines well developed and moderately long (PSI 32), about as long as the propodeal declivity, tapering evenly from the base, straight, 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 moderately long (PLI 175), without tubercles anterodorsally. Subpetiolar process in the form of a small, triangular, acute tooth; ventral margin of petiole weakly bulging medially. Petiolar peduncle short: comprising about a third of the petiole length. Petiolar node robust and subquadrate: transition between peduncle and node marked by a rounded angle of ~140 °, resulting in a weakly concave anterior node face; anterior face forming a ~110 ° angle with the dorsal face, which is weakly convex; dorsal face weakly convex, forming a rounded ~90 ° angle with the posterior face, which forms a ~90 ° angle with the caudal cylinder. Postpetiole evenly rounded anteriorly, convex dorsally, and weakly lobed ventrally.

In dorsal view, humeri moderately well developed: evenly rounded and slightly 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 absent: mesonotum and propodeum completely fused and lateral margins converging evenly to the bases of the propodeal spines. Propodeal spines broadly approximated basally and diverging apically, their apices separated from each other by about their length, the negative space between them “U” shaped. Petiolar peduncle with spiracles barely protruding past the lateral margins. Petiolar node evenly ovular, slightly longitudinally elongate, and narrowed anteriorly; node wider than the peduncle, and slightly broader than the caudal cylinder. Postpetiole moderately broad (PWI 206) 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 flat and evenly rounds into the lateral margins, which slightly diverge to the angulate posterior corners; posterior margin flat. Metafemur moderately incrassate (FI 298).

Sculpture: median clypeal carina present, extending posteriorly nearly to the frontal triangle, and flanked on either side by two equally strong carinae. Lateral clypeal lobes with additional, weaker carinae; ground sculpture smooth and shining. Antennal scapes shining through weak areolate ground sculpture. Cephalic dorsum smooth and shining, but with coarse piligerous punctures; very fine costulae flanking the frontal carinae medially. Lateral surfaces of head with weak areolate sculpture posterior to the compound eye, fine rugulose sculpture surrounding the compound eye, and fine, dense rugose sculpture between the compound eye and the mandibular insertion. Ventral surface of head smooth and shining, but with weak areolate sculpture posteromedially. Pronotal neck areolate. Lateral surfaces mesosoma areolate, with the sculpture arranged into longitudinal rows on the pronotum by costulae. Propodeal declivity weakly areolate. Dorsal surface of mesosoma uniformly areolate. Femora weakly areolate and shining feebly. Petiole predominantly areolate, but smooth and shining ventrally. Postpetiole predominantly weakly areolate-costulate, but smooth and shining anteromedially. First gastral tergite smooth and shining, with weak spectral iridescence. First gastral sternite smooth and shining.

Setae: antennal scapes and funiculi moderately long, decumbent pilosity. Dorsum of the head, pronotum, waist segments, and gaster with moderately abundant, erect, blunt-tipped setae, the longest of which are slightly shorter than the length of the compound eye. The head bears ~34, mesosoma ~18, petiole 6, postpetiole ~10, and first gastral tergite ~30 setae. Long, subdecumbent pubescence surrounding the gular region. Short, sparse pubescence present over the entire body, but difficult to detect against the lightly colored integument and dense ground sculpture.

Color: predominantly yellow, with head capsule, meso- and metapleurae, and gaster (except for the basal quarter) dark testaceous brown. Distal quarters of the femora light brown.

Gyne: Unknown.

Male: Unknown.

Etymology: Geographical, a reference to the municipality of Huehuetenango in the highlands of Western Guatemala.

Comments: Very little is known about the biology of Temnothorax huehuetenangoi . It was intercepted in quarantine from the orchid Odontoglossum bictoniense (now Rhynchostele bictoniensis ). The taxonomic affinities of this species remain unclear, although it is similar in habitus to T. tenuisculptus , a,lthough more lightly sculptured and bicolored.

Figures

Figure 117 Temnothorax huehuetenangoi holotype worker (USNMENT00529517). (A) Profile view. (B) Full-face view. (C) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-117