Crematogaster vermiculata, EMERY, 1895

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 : 926-927

CREMATOGASTER VERMICULATA EMERY, 1895

( FIG. 32 )

Crematogaster vermiculata Emery, 1895: 286 . Two syntype workers, ‘Los Angeles’ (Pergande) (MSNG) (examined). One worker here designated lectotype (CASENT0923320). See comments below about type locality.

Crematogaster coarctata subsp. vermiculata Emery ; Creighton 1950: 209.

Crematogaster vermiculata Emery ; Buren 1968: 91, 112.

Senior synonym of Crematogaster colei Buren , C. opuntiae Buren and C. rossi Buren ( Morgan & Mackay 2017: 396) ; here reversed.

Worker measurements (N = 10): HW 0.67–0.85, HL 0.64–0.81, SL 0.52–0.63, WL 0.72–0.93, MtFL 0.56– 0.7, MSC 3–9, A4SC 9–20, PP-SL/HW 0.14–0.21, CI 1.01–1.08, OI 0.23–0.26, SI 0.72–0.78, MtFL/HW 0.79–0.84, SPL/HW 0.17–0.21, SPTD/HW 0.39–0.48.

Discussion: This is a distinctive arboreal species of Crematogaster restricted to cypress and hardwood swamps of the south-eastern United States. It belongs to the C. lineolata clade, and its closest relatives are the Caribbean species, C. lucayana and C. sanguinea ( Fig. 1 ). Workers of C. vermiculata are easily recognized by the striking rugulose sculpture on the promesonotum that imparts a vermiculate (worm-like) appearance, a feature not seen in any other species in the United States. Crematogaster vermiculata also has notably short scapes and legs (SI 0.72–0.78, SL/HL 0.75–0.82, MtFL/HW 0.79–0.84, MtFL/HL 0.84–0.89) and moderately conspicuous standing pilosity on the mesosoma (uo to four hairs on each pronotal humerus and one to three on the mesonotal declivity) and on the gaster (MSC 3–9, A4SC 9–20). The propodeal spines are relatively short and stout (SPL/HW 0.17– 0.21, SPL/WL 0.15–0.19) and, in dorsal view, inwardly curved and directed posterad (SPTD/HW 0.39–0.48). Although the type locality is Los Angeles, California, the type specimens agree in all respects with the wellknown swamp-inhabiting species of the south-eastern United States, and there is no species in California – or indeed in all of western North America – that matches C. vermiculata . Hence we concur with Buren (1968) and Johnson (1988) that the type locality cited in the original description (Los Angeles) is an error. This is by no means the only locality or labelling error that can be attributed to Pergande; see other examples cited by Gregg (1969: 101), Ward (2000: 89) and Wetterer (2015: 132). Buren’s (1968) findings were overlooked by Morgan & Mackay (2017), who reverted to an outdated concept of C. vermiculata as a western Nearctic species, with outlying populations in southeastern United States, and they synonymized three western species ( C. colei , C. opuntiae and C. rossi ) under C. vermiculata . These three taxa are not closely related to C. vermiculata ( Fig. 1 ), nor do they bear any close morphological resemblance to that species.

Type notes: The two syntype workers of C. vermiculata are deposited in MSNG [not MHNG, as indicated by Morgan & Mackay (2017)] and are labelled ‘Los Angeles |Calif.’ and ‘ SYNTYPUS | Crematogaster |ver miculata|det. Emery, 1895’. One of the two workers also has a label with ‘No.|372’. The latter worker has been designated lectotype. There are four similar workers in the USNM labelled ‘ Los Angeles | Calif. ’, ‘ No. |372’ and ‘ Collection | T Pergande’, and one of these is additionally labelled ‘ Cremastogaster |vermiculata| Em. (372) Em. ’ in Pergande’s handwriting. These four workers in USNM are not true types, since Emery’s (1895: 286) description is based on two workers only, but they appear to be part of the same series. All six workers agree closely with Emery’s (1895) original description, particularly his mention of the almost parallel propodeal spines and the ‘peculiar worm-like sinuous wrinkled sculpture of the promesonotum’ .

Distribution and biology: Crematogaster vermiculata occurs from North Carolina to Florida and west to Louisiana and Arkansas. It is a strictly arboreal species, inhabiting cypress and hardwood swamps ( Johnson, 1988; Deyrup, 2017).

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 31–36. Crematogaster workers, showing lateral view of body (A), full-face view of head (B) and dorsal view of body (C). 31, C. cerasi lectotype (USNMENT00529078); 32, C. vermiculata (CASENT0914534); 33, C. rifelna holotype (LACMENT164556);34, C.ashmeadi (CASENT0922720); 35, C.pinicola (CASENT0172943); 36,C.pilosa(CASENT0914530). Images courtesy of AntWeb (www.antweb.org); photographers Michele Esposito (31, 33), Zach (Ziv) Lieberman (32, 36), Wade Lee (34), April Nobile (35).