Taxonomy in the phylogenomic era: species boundaries and phylogenetic relationships among North American ants of the Crematogaster scutellaris group (Formicidae: Hymenoptera) Author Ward, Philip S. Author Blaimer, Bonnie B. text Zoological Journal of the Linnean Society 2022 194 893 937 journal article 10.1093/zoolinnean/zlab047 0024-4082 10115063 6144DD31-0F7B-4589-86A3-F40994452C9 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.