Taxonomic history
Watkins, 1971 PDF: 96 (q.).Senior synonym of Neivamyrmex isodentatus: Snelling & Snelling, 2007 PDF: 483.Figures 9, 22, 40, 55, 82
Neivamyrmex moseri Watkins , 1969: 529 (w). U. S. A. , Louisiana , Rapides Parish , Kisatchue National Forest ( USNM ) examined .
Neivamyrmex isodentatus MacKay, 1998: 333 - 335 (w). U. S. A., Texas, Kleberg Co., Kleberg Airport (MCZC) examined. NEW SYNONYMY.
DISTRIBUTION (Map 4)
UNITED STATES: Louisiana and Texas.
SPECIMENS EXAMINED
In addition to the type material cited above, we have studied a small series from Texas, Bell Co., Bowmer Ranch 18 June 1970 (J. F. Watkins II; W 164; LACM , WPMC).
DISCUSSION
Neivamyrmex moseri is easily separated from all other described United States species by its unique mandibular structure: there are three large teeth that are usually approximately equal in size; much smaller intercalary denticles may be present. MacKay (1995) described N. isodentatus as a similar species that differed in details of mesosomal and petiolar sculpture, presence of a subantennal lamella, fewer short bristly hairs on the funiculus, and a subtle difference in the direction of the opening of the propodeal spiracle. None of these features is sufficiently distinctive to suggest a new species , since all are features that are typically variable in any species of Neivamyrmex . The types of N. isodentatus were compared with a few specimens from Bell County, Texas, identified by Watkins as N. moseri , but not with the types of that species. Had the N. isodentatus material been compared with N. moseri types, the conformity of the two would have been obvious. Both type series differ from the Bell County specimens in the same manner and we conclude that N. isodentatus is a synonym of N. moseri .
With the limited material available we are forced to agree with Watkins that the Bell County specimens are also N. moseri , even though differing in a few subtle features that are variable and somewhat illusory, depending upon the angle of view. We should note further that the statement by Watkins (1969) that N. moseri workers lack a subantennal lamella is only partly correct; the lateral extension of the frontal carina that runs below the socket is present, but is not elevated to form a distinct lamella in most specimens examined. A low lamella is present in a few specimens, but not to quite the same degree as seen in the types of N. isodentatus.
