STAT. REV.

(FIGS 9A, 24)

Crematogaster lineolata subsp. laeviuscula var. californica Emery, 1895: 285 (unavailable name).

Crematogaster laeviuscula var. californica Wheeler, W.M., 1919: 111 (first available use of name).

Syntype worker, Los Angeles, California (MSNG) (examined), here designated lectotype (CASENT0923319).

Crematogaster lineolata subsp. californica Wheeler; Wheeler, W. M., 1934a: 135.

Junior synonym of C. coarctata Mayr: Creighton, 1950: 207.

Status as species: Smith, M. R. 1951: 808; Buren, 1968: 94.

Junior synonym of C. coarctata Mayr: Morgan & Mackay 2017: 105; here overturned.

Worker measurements (N = 22): HW 0.86–1.30, HL 0.81–1.19, SL 0.72–0.97, WL 0.93–1.41, MtFL 0.76– 1.15, MSC 1–4, A4SC 6–25, PP –SL/HW 0.08–0.21, CI 1.04–1.14, OI 0.25–0.28, SI 0.75–0.84, MtFL /HW 0.83– 0.91, SPL/HW 0.19–0.25, SPTD/HW 0.47–0.56.

Discussion: It is unclear why Morgan & Mackay (2017) synonymized C. californica under C. coarcata. There are reliable morphological differences between these two species and our phylogenetic analyses show that they are found in distant parts of the tree: C. coarctata and C. marioni form a well-supported clade, sister to all other New World species of the C. scutellaris group, while C. californica belongs to a subcomplex of species in the C. opaca clade that includes C. opuntiae (see below) and related species (Fig. 1). In workers of C. californica, the dorsum of the promesonotum is densely reticulate-foveolate and opaque, with variable incursion of weak longitudinal striae or rugulae (Fig. 9A); standing pilosity is relatively sparse, with each pronotal humerus typically furnished with a single isolated seta; the eye is relatively large; and the appendages (scapes, legs) are relatively short. By contrast, in workers of C. coarctata (including its recently proposed junior synonym, C. mormonum), the promesonotum is longitudinally striate, with shiny interspaces intermingled with weak reticulatefoveolate sculpture (Fig. 9B), or it is predominantly smooth and shiny with weak irregular striae; standing pilosity is more common, usually manifested as two to three setae on each pronotal humerus; the eye is relatively smaller; and the appendages longer. Buren (1968) and Snelling & George (1979) employed pronotal pilosity to separate C. californica from C. coarctata (in the broad sense, including C. mormonum) but this distinction sometimes breaks down. There are occasional worker specimens of C. californica with no seta or two setae on one of the humeri and specimens of C. coarctata with a single hair on one of the pronotal humeri. More reliable are the differences in sculpture, eye size and metafemur length (Table 2). An index calculated as ED/ MtFL ranges from 0.25 to 0.28 in C. coarctata, and 0.29–0.32 in C. californica, and a bivariate plot of ED and MtFL highlights this distinction between the two species (Fig. 41).

Type notes: Crematogaster californica was described by Emery on the basis of two workers, one from Los Angeles and the other from Encinitas (San Diego County), California. Morgan & Mackay (2017: 111) claimed that the two syntype workers of C. californica are deposited in ‘MNHG’, apparently a misspelling of MHNG, but the types are not present in the Geneva collection (Bernard Landry, pers. comm.). The syntype from Los Angeles is in MSNG and has been examined by us. The second syntype, from Encinitas, is not in MSNG (Maria Tavano, pers. comm.) and must be presumed lost or misplaced. It was apparently examined by Morgan & Mackay (2017), so the loss is a recent one. Nevertheless, the Los Angeles syntype agrees well with the species that has come to be known as C. californica, and it serves as a suitable lectotype.

Distribution and biology: Crematogaster californica is a ground-nesting species that occurs from central California to Baja California Sur, in desert, chaparral, coastal sage scrub and open woodland. The eastern limits are unclear because of confusion with C. opuntiae (see discussion under that species). Crematogaster coarctata (type locality: San Francisco; syntype worker imaged on AntWeb: CASENT0902143) has a more northerly distribution than C. californica, but the ranges of the two species overlap in southern California and northern Baja California, and there is no evidence of intergradation where they co-occur.