Temnothorax goniops ( 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 : 180-184

Temnothorax goniops ( Baroni Urbani, 1978)

Distribution: Fig. 114B ; worker: Fig. 116 .

Leptothorax goniops Baroni Urbani, 1978: 445 , figs. 65, 100. Holotype worker. Campeche, Mexico.

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

Type material examined: Holotype worker: MEXICO: Campeche: 10 km S Campeche, 28–29 June 1953, E.O. Wilson #125 , 2nd growth thorn forest, strays, M.C.Z. Type 32436 ( MCZ-ENT00032436 , top) [ MCZC].

Paratype workers: same pin as holotype, 1 worker (MCZ-ENT00032436, bottom) [ MCZC]; same data as holotype, 1 worker (images of CASENT0912943 examined on antweb.org) [ NHMB] .

Non-type material examined: MEXICO: Chiapas: [no locality data], 8 March 1961, Jackson , 1 worker (CASENT0758363) [ USNM] .

Geographic distribution: Low elevations in southern and eastern Mexico ( Fig. 114B ).

Worker diagnosis: Temnothorax goniops 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 80–83); compound eyes small (OI 22–24); body very compact (WLI <130); metanotal groove absent; erect setae present on propodeum; propodeum not strongly depressed; propodeal spines about as long as the propodeal declivity (PSI 33–36). directed posterodorsally, and straight; propodeal spines broadly approximated in dorsal view (SBI> 30); hind femora weakly to moderately incrassate (FI 182–252); petiolar node erect and subquadrate, not overhanging the caudal cylinder in profile view; petiolar node compact, not elongate (NI 113–148); petiolar node broader than caudal cylinder in dorsal view (PNWI 123–140); postpetiole moderately broad (150 <PWI <220); head sculpture uniformly areolate; antennal scapes with short, decumbent pilosity; setae on head, mesosoma, waist segments and gaster erect, short, sparse and blunt (never long and tapering); integument yellow.

Similar species: Temnothorax aureus sp. nov., T. aztecus , T. paraztecus sp. nov., T. pilicornis sp. nov., T. rugosus , T. subditivus (light form), T. terrigena , T. torrei , species of the annexus and goniops groups. Temnothorax goniops differs from T. aztecus and T. paraztecus sp. nov. by, among many other characters, its smaller size (WL <0.7 mm vs.> 1 mm) and lack of long, tapering setae on head, mesosoma, legs, and gaster. Temnothorax goniops can be distinguished from T. pilicornis sp. nov. by the pilosity on the antennal scapes, which is decumbent in T. goniops , as opposed to subdecumbent in T. pilicornis sp. nov. The pedunculate petiole with an erect subquadrate node will separate T. goniops from T. aztecus , T. paraztecus sp. nov., and T. subditivus , which have squamiform petiolar nodes, T. aureus sp. nov., which has a posteriorly leaning petiolar node, and T. rugosus , which has a cuneiform to subcuneiform petiolar node. Temnothorax goniops differs from T. torrei by the presence of four erect setae on the dorsum of the petiolar node, as opposed to two. Temnothorax goniops can be distinguished from T. terrigena by the relatively long propodeal spines, which are longer than the propodeal declivity (shorter than the declivity in T. terrigena ). The members of the annexus group all have a medially emarginate anterior clypeal margin, which is entire and convex in T. goniops . Temnothorax goniops can be separated from other members of the goniops group by the yellow integument (bicolored in T. huehuetenangoi , and predominantly dark brown in T. ixili , T. achii sp. nov., and T. xincai sp. nov.), continuous dorsal margin of the mesosoma (the propodeum is depressed in T. xincai sp. nov.), long propodeal spines (shorter than the propodeal declivity in T. ixili and T. achii sp. nov.), and the uniformly areolate dorsum of the head (smooth and shining in T. huehuetenangoi ).

Worker measurements & indices (n = 3): SL = 0.378 –0.395 (0.384); FRS = 0.156 –0.160 (0.158); CW = 0.497 –0.524 (0.510); CWb = 0.453 –0.488 (0.472); PoOC = 0.212 –0.214 (0.213); CL = 0.520 –0.562 (0.544); EL = 0.120 –0.130 (0.126); EW = 0.089 –0.093 (0.092); MD = 0.116 –0.125 (0.121); WL = 0.558 –0.613 (0.594); SPST = 0.185 –0.222 (0.206); MPST = 0.196 –0.202 (0.198); PEL = 0.263 –0.275 (0.267); NOL = 0.137 –0.148 (0.143); NOH = 0.097 –0.121 (0.109); PEH = 0.190 –0.204 (0.197); PPL = 0.139 –0.180 (0.165); PPH = 0.161 –0.189 (0.172); PW = 0.317 –0.341 (0.331); SBPA = 0.147 –0.161 (0.155); SPTI = 0.219 –0.260 (0.234); PEW = 0.137 –0.144 (0.141); PNW = 0.174 –0.201 (0.185); PPW = 0.273 –0.288 (0.280); HFL = 0.311 –0.396 (0.357); HFWmax = 0.089 –0.109 (0.101); HFWmin = 0.042 –0.049 (0.045); CS = 0.713 –0.769 (0.744); ES = 0.167 –0.175 (0.172); SI = 80–83 (81); OI = 22–24 (23); CI = 87; WLI = 123–129 (126); SBI = 32–33 (33); PSI = 33–36 (35); PWI = 194–204 (199); PLI = 146–198 (165); NI = 113–148 (132); PNWI = 123–140 (132); NLI = 50–56 (54); FI = 182–252 (225).

Worker description: In full-face view, head subquadrate, longer than broad (CI 87). Mandibles densely, 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 evenly convex medially. Antennal scapes short: when fully retracted, failing to reach the posterior margin of the head capsule by about the width of the antennal scape (SI 80–83). Antennae 12-segmented; antennal club of composed of three segments, with the apical-most segment nearly twice as long as 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 weakly convex, nearly flat, forming a continuous arc from the mandibular insertions to the posterior margin of the head. Posterior head margin weakly emarginate, but predominantly flat and rounding evenly into the lateral margins.

In profile view, compound eyes ovular and moderately large (OI 22–24), with 9 ommatidia in longest row. Pronotal declivity indistinct, but junction of anterior and dorsal faces marked by a change in ground sculpture; neck and anterior face of pronotum forming a ~120 ° angle; anterior face and dorsal face forming a rounded ~130 ° angle. Mesosoma evenly convex from where it joins the pronotal declivity to the propodeal spines. 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 moderately well developed, directed posterolaterally, and separated from the propodeal declivity by about four spiracle diameters. Propodeal spines well developed and long (PSI 33–36), longer than the propodeal declivity, flared at the base, slightly upcurved at the apices, and acute. Propodeal declivity flat, with a lamina between the base of the propodeal spine and the propodeal lobe, forming a rounded ~100 ° 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 146–198), without tubercles anterodorsally. Subpetiolar process in the form of a small, acute tooth; ventral margin of petiole flat posterior to it. Petiolar peduncle moderately long: comprising about half the length of the petiole. Petiolar node robust and subquadrate: transition between peduncle and node marked by a rounded angle of ~130 °, resulting in a concave anterior node face; anterior face forming a ~100 ° angle with the dorsal face, which is weakly convex; dorsal face rounding evenly into the short posterior face, which forms a ~90 ° angle with the caudal cylinder. Postpetiole flat anteriorly, rounding into the weakly convex dorsal face; weakly lobed ventrally.

In dorsal view, humeri weakly 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 not protruding past the lateral margins. Petiolar node campaniform: evenly rounded anteriorly, and very weakly convex posteriorly, nearly flat. Node wider than the peduncle, and about one and a quarter times as wide as the caudal cylinder. Postpetiole moderately broad (PWI 194–204) 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 weakly emarginate medially, and evenly rounds into the lateral margins, which diverge slightly to the angulate posterior corners; posterior margin flat. Metafemur weakly to moderately incrassate (FI 182–252).

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 weakly areolate. Antennal scapes areolate. Cephalic dorsum uniformly densely areolate, with areolae organized into longitudinal rows by costulae, which become stronger near the frontal carinae; fine, concentric costulae surrounding the antennal insertions. Lateral surface of head densely areolate, with rugulose sculpture between the compound eye and the mandibular insertion. Ventral surface of head weakly areolate. Mesosoma uniformly areolate laterally, with fine costulae on the lateral face of the propodeum, meso- and metapleurae. Propodeal declivity shining through weakly areolate sculpture. Dorsal surface of mesosoma uniformly areolate, with rugulose sculpture on the pronotum. Femora shining through weak areolate sculpture. Petiole and postpetiole uniformly areolate; petiolar node costulate. First gastral tergite smooth and shining, with weak spectral iridescence. First gastral sternite smooth and shining.

Setae: antennal scapes and funiculi with 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 about the width of the compound eye. The head bears ~30, mesosoma ~20, petiole 6, postpetiole ~14, and first gastral tergite ~30 setae. Short, sparse pubescence present over the entire body, but difficult to detect against the lightly colored integument and dense sculpture.

Color: predominantly yellow, with masticatory margin of the mandible dark brown.

Gyne: Unknown.

Male: Unknown.

Etymology: Morphological, from the Greek ‘gonia’ (= angle) + ‘opsis’ (= sight), a reference to the weak anterior angle on the compound eyes.

Comments: Little is known about the biology of Temnothorax goniops . It appears to be distributed widely across Southern Mexico and the Yucatán peninsula: in addition to the type locality in Campeche and the collection from Chiapas noted by Baroni Urbani (1978), T. goniops has been reported from evergreen rainforest in Quintana Roo state, specifically the Mayan ruins at San Gervasio on the Isla de Cozumel by Reynoso-Campos, Rodríguez-Garza & Vásquez-Bolaños (2015), and the Reserva Ecologica de San Felipe Bacalar by Rodríguez-Garza (2015). Additionally, Vásquez-Bolaños (2011) records T. goniops from Yucatán state. I have not been able to examine these specimens personally, so I exclude them here.

Figures

Figure 114 Geographical and elevational distribution of the goniops group. (A) Temnothorax achii sp. nov. (B) T. goniops (C) T. ixili (D) T. xincai 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, non-type localities are represented by circles. Bounding box in inset map shows location of main map. Map for T. huehuetenangoi not included due to the uncertainty of the collection locality. Full-size DOI: 10.7717/peerj.11514/fig-114

Figure 116 Temnothorax goniops holotype worker (MCZENT00032436). (A) Profile view. (B) Fullface view. (C) Dorsal view. Scale bars 0.2 mm. Full-size DOI: 10.7717/peerj.11514/fig-116