Temnothorax quasimodo

The unusual form of both the mesosoma and broadening of postpetiole may indicate that this is a socially parasitic or inquilinous species (Wilson 1984), perhaps in nests of such other species as Temnothorax andrei. We did not observe similar morphological modifications among multiple nest series and hundreds of specimens of T. andrei examined during this study. T. quasimodo was found in a locality where intensive sampling has been carried out, mostly by Philip S. Ward (pers. comm.) and UC Davis entomology students, but the species has been collected only once. We conclude that it represents an extremely infrequently encountered species such as Lasius atopus (Cole, 1958a) or Stigmatomma trigonignathum (Brown, 1949), although until more material is collected we cannot be certain that the holotype is not a result of a rare environmentally induced malformation. (Snelling et al. 2014)

Identification
Snelling et al. (2014) - Mesosoma short and deep in profile, dorsum distinctly convex; propodeum without spines but with blunt obtuse angles. The short, deep mesosoma with distinctly convex dorsum results in a “hunched” profile that is characteristic for this species. This profile is similar to that of some species placed in the erstwhile subgenus Macromischa Roger (1863).

Superficially this species resembles Temnothorax andrei, a species that is common in similar habitat and was collected in the same litter sample as T. quasimodo (P. S. Ward, pers. comm.). The distinctive mesosomal profile of T. quasimodo will readily distinguish between the two.

Key to Temnothorax of California

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

Castes
Known only from the worker caste.

Nomenclature

 *  quasimodo. Temnothorax quasimodo Snelling, Borowiec & Prebus, 2014: 69, figs. 17, 24 (w.) UNITED STATES.

Worker
measurements (mm) (1 measured). EL 0.090; HFL 0.334; HFW 0.102; HL 0.529; HW 0.416; IOD 0.364; OMD 0.123; PPW 0.250; PSL N/A; PTW 0.193; PW 0.298; SL 0.339; WL 0.587. Indices: CI 78.6; FI 80.3; OI 17.0; PI 130; PSI N/A; SI 64.1.

Head longer than broad in frontal view; posterior margin transverse and weakly concave in middle; lateral margins weakly curved and slightly convergent toward mandibular bases. Antenna 12-segmented; scape short and ending well below posterior margin; apical club distinctly three-segmented. Eye small, IOD 4.04 × EL; EL 0.73 times OMD. Mandible moderately coarsely rugulose (rugulae finer than in Temnothorax andrei. Head moderately shiny and with narrow shiny median line; surface mostly very finely lineolate (“striate”) and with dense (especially anteriorly) minute shallow punctures becoming sparser and less distinct posteriorly and with scattered coarser piligerous punctures; antennal fossa and malar area only slightly shiny and roughened between well-separated fine rugulae (straight on malar area, curving mesad over fossa). Dorsum of head with widely scattered short, erect to suberect yellowish setae, the setae stiff and slightly flattened; similar but longer setae beneath.

Mesosoma stout, WL 1.97 times PW; mesosomal profile deep, distance from dorsal mesonotal margin to base of mesocoxa 0.50 times WL; mesosomal dorsum distinctly convex in profile. Propodeal spines reduced to blunt obtuse angles in profile. Mesosoma opaque and reticulate, except infraspinal face of propodeum less strongly sculptured and shinier. Dorsum with about 20 sparse slightly flattened yellowish setae that are longer than those of head. Metafemur robust, 3.27 times longer than wide in dorsal view.

Petiole lacking anterior peduncle; node robustly triangular in profile with rounded summit; subpetiolar process consisting of a distinct thin flange that is acute anteriorly. Postpetiolar node profile high and rounded and in dorsal view trapezoidal with pronounced anterior corners and 1.30 times width of petiolar node. Sculpture and pilosity of both nodes similar to those of mesosoma.

Gaster in dorsal view 2.26 times wider than node of postpetiole; disc of first tergum smooth and shiny with scattered minute piligerous punctures; setae fine and yellowish, slightly flattened; remaining segments with similar setae.

Color of body and appendages uniformly yellow.

Type Material
Holotype worker, U.S.A.: CALIFORNIA: Solano Co.: Cold Canyon, 19 km NNW Vacaville, 300m, 38.5° -122.1°, 25.ii.1990 (P. S. Ward, #10562-3) ex sifted litter (leaf mold, rotten wood), chaparral (CASENT0005694) [UCDC].

Etymology
Temnothorax quasimodo is named for the Victor Hugo character in his novel The Hunchback of Notre Dame.