Temnothorax caguatan

This widely distributed arboreal species has been collected in a variety of habitats, ranging from oak woodland to grey pine and Sequoia forests, but the preponderance of the records have been from oak woodland. It has been found in association with a number of tree and shrub species: Arctostaphylos spp., Pinus jeffreyi, Quercus agrifolia, Q. chrysolepis and Q. kelloggii. Nest samples have been taken from dead branches of all three Quercus species and one was from a dead branch of P. jeffreyi.

Identification
Prebus (2017) - A member of the rugatulus clade.

Snelling et al. (2014) - Antenna 11-segmented; propodeal spines distinct and more than half as long as distance between their bases; node of petiole node subrectangular in profile; head and mesosoma coarsely rugose and with reticulate interspaces.

Because the antennae are 11-segmented and the propodeal spines are long, among our California species T. caguatan can only be confused with Temnothorax rugatulus, which has a shorter petiole node with acute top and relatively more slender hind femur. The latter also typically nests in soil, commonly under covering objects such as small stones, although collections are known from dead wood and arboreal sites (P. S. Ward pers. comm.).

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Nomenclature

 *  caguatan. Temnothorax caguatan Snelling, Borowiec & Prebus, 2014: 41, figs. 1, 6–8, 20, 24–26 (w.q.m.) UNITED STATES.

Worker
measurements (mm) (18 measured). EL 0.150–0.179 (0.162); HFL 0.461–0.582 (0.507); HFW 0.120–0.147 (0.129); HL 0.674–0.769 (0.706); HW 0.560–0.673 (0.604); IOD 0.486–0.585 (0.526); OMD 0.158–0.194 (0.171); PPW 0.257–0.321 (0.279); PSL 0.153–0.203 (0.166); PTW 0.192–0.259 (0.214); PW 0.387–0.480 (0.421); SL 0.437–0.524 (0.464); WL 0.757–0.927 (0.826). Indices: CI 81.8–88.5 (85.5); FI 79.7–90.5 (83.9); OI 21.7–24.4 (23.0); PI 123–138 (131); PSI 22.4–26.4 (23.5); SI 64.0–68.1 (65.7).

Head longer than broad in frontal view; lateral margins parallel or nearly so; posterior margin transverse. Antenna 11-segmented with indistinct apical 3-segmented club; scape ending below posterior margin by more than its apical width. Eye small; IOD 3.04–3.44 × EL; EL 0.88–1.04 × OMD. Mandibles coarsely longitudinally rugose. Median carina of clypeus flanked on each side by three about equally strong carinae. Dorsum of head with coarse longitudinal rugae that diverge slightly posteriorly; posterior one–third to one–half with coarse rugoreticulosity; interspaces slightly shiny with shallow punctures. Dorsum with sparse erect, stiff, blunt–tipped yellowish setae; ventral surface with several longer acute setae on each side.

Mesosoma slender, WL 1.91–2.03 × PW; profile of mesosomal dorsum nearly flat, sometimes weakly depressed at metanotal suture. Propodeal spines well developed, PSI 22.4–26.4, slightly down–curved in profile and about as long as distance between their bases. Dorsum and sides with strong, well–separated longitudinal rugae, interspaces contiguously punctate and slightly shiny; pronotum anteriorly usually with some reticulae. Metafemur 3.72–4.23 × longer than thick in dorsal view. Dorsum with 20+ short standing setae along entire length.

Petiole with anterior peduncle; node in profile subrectangular, dorsal face sloping posteriorly, flat to slightly convex; posterior face short; subpetiolar tooth prominent, usually acute; Postpetiole rectangular in dorsal view and 1.23–1.38 times as wide as petiole node. Petiole node rugoreticulate, postpetiole similar and with weak longitudinal rugae at sides; both nodes finely reticulate between rugae. Each with 6–10 standing setae that are longer than those of mesosoma.

Gaster, in dorsal view, 2.40–2.66 times wider than node of postpetiole. Disc of first tergum smooth and shiny between sparse, distinct piligerous punctures. All segments with numerous long, narrowly rectangular to subacute yellowish setae.

Head and body light to dark reddish-brown, mesosoma lighter than either head or gaster.

Queen
measurements (1 measured): EL 0.246; HFL 0.740; HFW 0.162; HL 0.811; HW 0.762; IOD 0.633; OMD 0.164; PPW 0.405; PSL 0.178; PTW 0.305; PW 0.814; SL 0.549; WL 1.446. Indices: CI 94.0; FI 97.1; OI 30.3; PI 133; PSI 22.0; SI 67.7.

Head longer than broad, margins approximately parallel in frontal view and broadly rounded into transverse posterior margin. Antennal scape extending back to level of lateral ocellus. Eye large and moderately convex, IOD 2.57 × EL in frontal view; EL 1.50 × OMD. Sculpture and pilosity about as in worker.

Mesosoma slender, WL 1.78 × PW. Mesonotum flat in profile. Propodeal spines thick at base, about half as long as infraspinal distance. Mesoscutum with conspicuous longitudinal rugae, and interspaces weakly reticulate; mesoscutellum also rugose, but more irregularly, underlying irregular sculpture more pronounced than on mesoscutum. Side of pronotum duller and with distinct fine reticulum; mesepisternum shinier and finely reticulate anteriorly to longitudinally rugose posteriorly; propodeum dull, finely reticulate with striae in anterior portion. Pilosity suberect to erect, short (less than 0.1 mm), not flattened and relatively sharp-tipped. Remainder as described for worker; gaster 2.95 × as wide as postpetiole.

Male
measurements (mm) (2 measured): EL 0.212–0.238 (0.225); HFL 0.686– 0.695 (0.691); HFW 0.075–0.084 (0.080); HL 0.502–0.523 (0.513); HW 0.481– 0.483 (0.482); IOD 0.333–0.376 (0.355); OMD 0.052–0.058 (0.055); PPW 0.221– 0.225 (0.223); PSL N/A; PTW 0.173–0.181 (0.177); PW 0.641–0.668 (0.655); SL 0.140–0.150 (0.145); WL 1.044–1.150 (1.097). Indices: CI 92.4–95.8 (94.1); FI 143–144 (143); OI 40.5–47.4 (44); PI 124–128 (126); PSI N/A; SI 27.9–28.7 (28.3).

Head longer than broad, margins behind eyes slightly convergent and broadly rounded into weakly convex posterior margin. Eyes large and strongly bulging; IOD 1.57–1.58 × EL; OMD very short, about equal to transverse diameter of anterior ocellus; interocellar distance 2.30–2.40 and ocellocular distance 2.20–2.30 times diameter of anterior ocellus. Scape less than a third the length of IOD. Head finely reticulate and with regular longitudinal rugae dorsally and circling the eyes. Dorsum of head with erect setae which are long and sharp–tipped.

Mesosoma robust, WL 1.56–1.79 × PTW. Propodeal spines absent. Sculpture fine and weak, mesoscutal dorsum with very fine longitudinal rugosity, mesoscutellum mostly smooth with scattered rugae. Mesoscutum with scattered suberect short, slender setae; several pairs of longer setae submedially on mesoscutellum.

Summit of petiole node low, broadly convex in profile; subpetiolar process absent.

Mesosoma and petiolar segments brownish yellow; appendages yellow; head and gaster reddish brown.

Type Material
Holotype worker, U.S.A.: CALIFORNIA: San Diego Co.: Wooded Hill 3km SW Mount Laguna, 1800 m, 32.85° -116.43°, 26.v.2004, (P. S. Ward, #15252), ex dead branch of Pinus jeffreyi, P. jeffreyi forest (CASENT0339251). Paratypes. Same data as the holotype, 1 worker (CASENT0339252), 1 worker (CASENT0339253) AMNH, 1 worker (CASENT0339254) AMNH, 1 worker (CASENT0339255) , 1 worker (CASENT0339256) CASC, 1 worker (CASENT0339257) CASC, 1 worker (CASENT0339258) , 1 worker (CASENT0339259) LACM, 1 worker (CASENT0339260) LACM, 1 worker (CASENT0339261) , 1 worker (CASENT0339262) USNM, 1 worker (CASENT0339263) USNM; 1 dealate gyne, 2 workers (CASENT0339250) , 1 worker (CASENT0339264) UCDC, 1 worker (CASENT0339265) UCDC, 1 worker (CASENT0339266) UCDC.

Etymology
Etymology. When Hernán Cortéz was conquering central Mexico, the Nahua speaking people related to him tales of a fabulous land, ruled by women, far to the northwest that was rich in gold and gems. They named this land “Caguatán”, the Land of Women. This tale presumably inspired Cortéz and other avaricious conquistadors to search for this marvelous land, ultimately leading the Spaniards to the Californias. The name California is that used by some fiction writers and explorers of the time for a mythical land inhabited by beautiful black women ruled by their queen, Calafia.

References based on Global Ant Biodiversity Informatics

 * Des Lauriers J., and D. Ikeda. 2017. The ants (Hymenoptera: Formicidae) of the San Gabriel Mountains of Southern California, USA with an annotated list. In: Reynolds R. E. (Ed.) Desert Studies Symposium. California State University Desert Studies Consortium, 342 pp. Pages 264-277.
 * Snelling R.R., M. L. Borowiec, and M. M. Prebus. 2014. Studies on California ants: a review of the genus Temnothorax (Hymenoptera, Formicidae). ZooKeys 372: 2789. doi: 10.3897/zookeys.372.6039