Crematogaster colei, BUREN, 1968

Ward, Philip S. & Blaimer, Bonnie B., 2022, Taxonomy in the phylogenomic era: species boundaries and phylogenetic relationships among North American ants of the Crematogaster scutellaris group (Formicidae: Hymenoptera), Zoological Journal of the Linnean Society 194, pp. 893-937 : 912-914

CREMATOGASTER COLEI BUREN, 1968 , STAT. REV.

( FIG. 20 )

Crematogaster colei Buren, 1968: 108 . Holotype worker, Wooten, Sacramento Mts. , New Mexico, 7500 ft, 4 July 1917 (Wheeler) (USNM) ( USNMENT00528846 ) (examined).

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

Worker measurements (N = 12): HW 0.73–1.06, HL 0.71–0.99, SL 0.68–0.89, WL 0.82–1.19, MtFL 0.71– 1.01, MSC 0–2, A4SC 0–11, PP-SL/HW 0.12–0.15, CI 1.03–1.09, OI 0.25–0.28, SI 0.82–0.92, MtFL/HW 0.94– 1.00, SPL/HW 0.21–0.26, SPTD/HW 0.48–0.60.

Discussion: Morphological and phylogenomic data affirm that C. colei and C. vermiculata are distantly related, falling in the C. opaca clade and C. lineolata clade, respectively ( Fig. 1 ). Crematogaster colei can be recognized by the features mentioned by Buren (1968), particularly the relatively elongate scapes (SI 0.82–0.92, SL/HL 0.88–0.96) and well-developed hemilobes of the postpetiole that are sharply angulate in profile. This species is also characterized by relatively long legs (MtFL/HW 0.94–1.00, MtFL/HL 0.99–1.08), long propodeal spines (SPL/HW 0.21–0.26), sparse standing pilosity (MSC 0–2, A4SC 0–11) and predominantly reticulate-foveolate sculpture on the mesosoma, overlain by weak rugulae. Crematogaster vermiculata is different: it has relatively short scapes (SI 0.72–0.78), short legs (MtFL/HW 0.79–0.84), short propodeal spines (SPL/HW 0.17–0.21), more abundant standing pilosity (MSC 3–9, A4SC 9–20) and distinctive rugulose sculpture on the promesonotum (see further discussion under that species). Crematogaster colei is actually more similar to C. californica , C. depilis and C. opuntiae (see below) than to C. vermiculata . It can be distinguished from those three taxa by the longer legs (see measurements cited above, compared to MtFL/HW 0.80–0.91 and MtFL/HL 0.84–0.98 in C. californica , C. depilis and C. opuntiae ) ( Fig. 42 ), smaller eye size (ED/MtFL 0.26–0.28 in C. colei , compared to ED/MtFL 0.29–0.37 in the other three taxa) and by the hemilobes of the postpetiole being weakly sculptured and sublucid (usually reticulatefoveolate and subopaque in the other three taxa). In addition, the postpetiolar seta is either absent or short in C. colei (PP-SL/HW 0–0.15) and usually present and longer (PP-SL/HW 0.12–0.21) in C. californica and C. opuntiae . For differences between C. colei and the newly described C. detecta , see under the latter species.

Distribution and biology: Crematogaster colei is a denizen of desert grassland and oak-pine-juniper woodland of the American South-West. It is known from west Texas, New Mexico, southern Utah, Arizona and northern Mexico. Colonies have been collected under stones and (once) in a dead branch of live oak.

Figures

Figure 1. Phylogeny of the North American Crematogaster scutellaris group. Maximum likelihood phylogenetic tree estimated from the 90% taxon completeness matrix after application of spruceup trimming with a 0.98 cut-off (90%-0.98-spruceup), using a combined best tree and ultrafast bootstrap (N = 1000) search in IQ-TREE v.1.6.12 and implementing 746 partitions. The analysis was rooted using the most distantly related outgroup taxon C. cf.rogenhoferi; the long branch leading to this taxon has been shortened for space-saving purposes. All nodes have bootstrap support = 100% unless labelled otherwise. Species images courtesy of AntWeb (www.antweb.org).

Figures 19–24. Crematogaster workers, showing lateral view of body (A), full-face view of head (B) and dorsal view of body (C). 19, C. mutans worker (CASENT0922736); 20, C. colei (CASENT0922726); 21, C. detecta holotype (CASENT0863461); 22, C. larreae paratype (CASENT0005943); 23, C. depilis (CASENT0005668); 24, C. californica lectotype (CASENT0923319). Images courtesy of AntWeb (www.antweb.org); photographers Wade Lee (19, 20), Zachary Griebenow (21), April Nobile (22, 23), Michele Esposito (24).

Figures 40–47. Bivariate plots of selected worker measurements in the Crematogaster scutellaris group. 40, PP-SL (postpetiole seta length) by HW (head width) in C. browni (N = 16) and C. cerasi (N = 17); 41, ED (eye diameter) by MtFL (metafemur length) in C. californica (N = 22) and C. coarctata (N = 21); 42, MtFL (metafemur length) by HW (head width) in C. californica (N = 22), C. colei (N = 12) and C. opuntiae (N = 10); 43, MtFL (metafemur length) by HW (head width) in C. depilis (N = 15), C. detecta (N = 11) and C. larreae (N = 5); 44, MtTL (metatibia length) by HW (head width) in C. depilis (N = 15), C. detecta (N = 11) and C. larreae (N = 5); 45, SPL (propodeal spine length) by HW (head width) in workers of C. hespera (N = 18), C. laeviuscula (N = 25) and C. parapilosa (N = 15); 46, SL (scape length) by HW (head width) in C. emeryana (N = 12) and C. marioni (N = 18); 47, SPTD (propodeal spine tip distance) by HW (head width) in C. lineolata (N = 26) and C. punctulata (N = 15).