Explanation of Names
Novo=new, messor=harvester, reaper.
Thus, this is a New World harvester ant by name, though it is in fact more of a scavenger-predator of fellow arthropods, and less often gathers seeds.
Largish ants 7-10 mm body length. Slender and long legged, resembling a large Aphaenogaster, and indeed, have been placed in and out of the latter over the years. Differentiating characteristics:
- >7mm outstretched body length (length less than 7mm, usually less than 5mm for Aphaenogaster)
-long curved setae on underside of head forming a psammophore (vs. usually no hairs on ventral head surface)
-postpetiole (abd. III) broadly joined, without posterior constriction, to the first gastral (abd. IV) segment (vs. postpetiole constricted posteriorly)
-hot desert habitat, nest in soil with conspicuous crater surrounding the entrance, forage in the open during cool parts of the day (vs. moist microhabitats in desert to more mesic habitats outside of desert region, a few desert Aphaenogaster spp. more abundant in cool deserts, forage cryptically, and arenocturnal or inhabit vertebrate burrows)
hot deserts of the US Southwest and Mexico.
creosote or other shrub-dominated deserts, sparse desert grassland, or bases of hills adjoining these habitats
Mostly predator-scavengers of other arthropods, opportunistically gather seeds and other plant parts, though these often end up as nest entrance adornment.
Recent multiple gene plus morphology-based phylogeny showed these to be the sister group of Veromessor, and these together the sister group of Aphaenogaster, so revived to genus level out of Aphaenogaster.
DeMarco B.B., Cognato A.I. (2015) Phylogenetic analysis of Aphaenogaster
supports the resurrection of Novomessor
(Hymenoptera: Formicidae). Ann. Ent. Soc. Am. 108: 201-210 (Full text