CREMATOGASTER OPUNTIAE BUREN, 1968, STAT. REV.

(FIG. 25)

Crematogaster opuntiae Buren, 1968: 120 .

Holotype worker, Santa Rita Experimental Range, Arizona (Buren) (LACM) (examined) .

Junior synonym of C. vermiculata: Morgan & Mackay, 2017: 396; here overturned.

Worker measurements (N = 10): HW 0.86–1.21, HL 0.80–1.11, SL 0.72–0.94, WL 0.89–1.27, MtFL 0.74– 1.05, MSC 1–3, A4SC 5–16, PP-SL/HW 0.14–0.19, CI 1.05–1.11, OI 0.26–0.29, SI 0.75–0.84, MtFL/HW 0.85– 0.89, SPL/HW 0.19–0.25, SPTD/HW 0.50–0.59.

Discussion: Crematogaster opuntiae bears little similarity or close phylogenetic relationship (Fig. 1) to the eastern, swamp-inhabiting species C. vermiculata, under which it was synonymized by Morgan & Mackay (2017). Among obvious differences, it has longer scapes and legs (SL/HL 0.83–0.90 and MtFL/HL 0.91–0.95 compared to SL/HL 0.75–0.82 and MtFL/HL 0.84–0.89 in C. vermiculata), predominantly reticulate-foveolate sculpture on the promesonotum, more divergent propodeal spines (SPTD/ PPW 1.71–1.96 compared to 1.15–1.48 in C. vermiculata) and lesser amounts of standing pilosity (MSC 1–3 and A4SC 5–16, compared to MSC 3–9 and A4SC 9–20 in C. vermiculata). As noted by Buren (1968), C. opuntiae is similar to C. californica, differing primarily by the shinier head and by the more appressed pubescence on the scapes and head. The relationship of C. opuntiae to C. californica remains to be clarified – they may well prove to be conspecific. Crematogaster opuntiae has similar eye, scape, leg (Fig. 42) and propodeal spine dimensions as C. californica, and in our phylogenomic analyses the two are sister-taxa (Fig. 1).

Distribution and biology: Buren (1968) recorded C. opuntiae from desert and semi-desert regions of Arizona and considered C. californica to be restricted to California and Baja California. Both taxa are ground-nesting.