Neivamyrmex minor

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Neivamyrmex minor
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Neivamyrmex
Species: N. minor
Binomial name
Neivamyrmex minor
(Cresson, 1872)

Neivamyrmex minor casent0005331 profile 1.jpg

Neivamyrmex minor casent0005331 dorsal 1.jpg

Neivamyrmex minor occurs in a wide variety of habitats it is one of the most frequently encountered Neivamyrmex species, and is commonly collected at light. The female castes are currently unknown but, based on ranges, we posit that Neivamyrmex leonardi will prove to be the worker. Although this species has been collected in variety of habitats, it has only rarely been collected in the desert areas of the west. Elevational amplitude ranges from near sea level to about 7000 feet. (Snelling and Snelling 2007)

Identification

Smith (1942) - The male of minus can be distinguished from those of other species by its small size and slender form; by the shape of the mandibles; by the posterior corner of the head not being strongly protuberant between the eye and the lateral ocellus; by the shape and length of the antennal scapes; by the flat or feebly concave area of the head back of the ocelli; by the lack of an occipital flange; by the nature of the pilosity; and by the color of the body and wings.

The male is more variable than that of Neivamyrmex melshaemeri. Such variation includes width of space between eye and lateral ocellus; production of head behind eyes; distinctness of lines on mesonotum; color (light brown to deep brown with the head black on some individuals and scarcely darkened on others); length of pilosity; and coarseness of punctation. Specimens from Mexico are much more robust, deeply colored, and coarsely punctured than are the specimens from Texas northward.

The male of minus is most likely to be confused with that of melshaemeri and Neivamyrmex fuscipennis. It differs from both these species in lacking the prominent posterior corners of the head. It can be distinguished from the former by the absence of long, suberect to erect hairs on the thorax and gaster; and from the latter by its much paler, semitransparent wings.

Distribution

United States: Texas to Kansas, west to southern Nevada and California; Mexico: Baja California, Baja California Sur, Coahuila.

Distribution based on Regional Taxon Lists

Nearctic Region: United States (type locality).
Neotropical Region: Mexico.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Males have been collected from April through August, but more commonly during July and August. (Smith 1942)

Castes

Only known from the male caste.

Male

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • minor. Labidus minor Cresson, 1872: 195 (m.) U.S.A. Combination in Eciton (Labidus): Mayr, 1886d: 441; in E. (Acamatus): Emery, 1900a: 187; in E. (Neivamyrmex): Smith, M.R. 1942c: 574; in Neivamyrmex: Borgmeier, 1953: 8. [Misspelled as minus by Dalla Torre, 1893: 4.] See also: Borgmeier, 1955: 630; Snelling, G.C. & Snelling, R.R., 2007: 481.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Male

Smith (1942) - Length 8.75 mm.

Head approximately one and seven-tenths times as broad as long. Eye large, convex, protuberant. Ocelli rather large, placed on protuberance above general surface of head; summit of protuberance concave; lateral ocellus usually about one-half its greatest diameter from inner border of eye. Frontal carinae subparallel or faintly divergent posteriorly, with groove between them extending to anterior ocellus. Antennal scape robust, longer than combined length of first 3 funicular segments, but not so long as combined length of first 4 segments; segments 1 and 2 distinctly broader than long, segments 3 to 5 inclusive feebly enlarged, segments 4 to 12 inclusive clearly longer than broad. Posterior corners of head not angularly protuberant as in fuscipennis and melsheimeri. Mandible moderately long, curved, gradually tapering from base toward apex, where it ends in an extremely acute, incurved point; shorter and more robust than in the two species mentioned above. Head, from above, weakly projecting behind eyes, more rounded immediately behind and adjacent to eyes than in fuscipennis and melsheimeri. Eye occupying approximately all of side of head except the produced and feebly ridged corner posterodorsad of eye. Region of head behind ocelli, in profile, flattened or feebly concave. Occipital flange lacking. Thorax longer than high, proportionally higher than in melsheimeri; somewhat projecting above head. Mesonotum convex, with anteromedian and parapsidal lines, these distinct in some specimens, less distinct in others. Epinotum, in profile, subtruncate or feebly concave. Legs remarkably small. Sides sharply margined through anterior half of petiole. Tarsal claws feebly toothed. Gaster slender, compressed, with distinct constrictions between segments. Sixth gastric tergum with a transverse impression near base. Seventh gastric sternum with two acute lateral teeth, and a less acute intermediate tooth. Paramere short, but abruptly enlarged apically to form a blunt, somewhat spear-shaped structure.

Head shining; thorax and gaster more subopaque owing to the dense, short, and closely appressed hairs; thorax more subopaque than gaster. Punctation more or less concealed by the pubescence, coarsest on posterior part of mesonotum and pleura.

Hairs yellowish, short, dense, much appressed on all parts of body; longer and suberect to erect on head, scapes, and ventral surface of body; hairs on head less dense than on appendages.

Brown; head darkest, thorax less dark, and gaster least dark of all. Wings very pale, semitransparent, with extremely light veins and distinct brown stigma.

References

  • Borgmeier, T. 1953. Vorarbeiten zu einer Revision der neotropischen Wanderameisen. Stud. Entomol. 2: 1-51 (page 8, Combination in Neivamyrmex)
  • Borgmeier, T. 1955. Die Wanderameisen der neotropischen Region. Stud. Entomol. 3: 1-720 (page 630, see also)
  • Cresson, E. T. 1872. Hymenoptera Texana. Trans. Am. Entomol. Soc. 4: 153-292 (page 195, male described)
  • Emery, C. 1900e. Nuovi studi sul genere Eciton. Mem. R. Accad. Sci. Ist. Bologna (5)8:173-188 (page 187, Combination in E. (Acamatus))
  • Mayr, G. 1886d. Die Formiciden der Vereinigten Staaten von Nordamerika. Verh. K-K. Zool.-Bot. Ges. Wien 36: 419-464 (page 441, Combination in Eciton (Labidus))
  • Smith, M. R. 1942c. The legionary ants of the United States belonging to Eciton subgenus Neivamyrmex Borgmeier. Am. Midl. Nat. 27: 537-590 (page 574, Combination in E. (Neivamyrmex))
  • Snelling, G. C.; Snelling, R. R. 2007. New synonymy, new species, new keys to Neivamyrmex army ants of the United States. In Snelling, R. R., B. L. Fisher, and P. S. Ward (eds). Advances in ant systematics (Hymenoptera: Formicidae): homage to E. O. Wilson - 50 years of contributions. Memoirs of the American Entomological Institute 80:459-550. PDF