Cyphomyrmex rimosus (Spinola)

Snelling, R. R. & Longino, J. T., 1992, Revisionary notes on the fungus-growing ants of the genus Cyphomyrmex, rimosus-group (Hymenoptera: Formicidae: Attini)., Insects of Panama and Mesoamerica: selected studies., Oxford: Oxford University Press, pp. 479-494: 491

publication ID

13137

persistent identifier

http://treatment.plazi.org/id/54F04EA5-2233-0C51-626F-FEB5778B1679

treatment provided by

Christiana

scientific name

Cyphomyrmex rimosus (Spinola)
status

 

Cyphomyrmex rimosus (Spinola)   HNS   (Figs 30.9, 30.17, 30.21, 30.2 5)

Cryptocerus? rimosus Spinola   HNS   , 1 8 5 3:65;

Meranoplus difformis F. Smith   HNS   , 1858:195;

Cataulacus deformis   HNS   (sic') Roger, 186 3:2 10. new synonymy.

Cyphomyrmex rimosus   HNS   : Emery, 189 3: 2. Emery, 1894:224, 225.

Cyphomyrmex rimosus var. fuscus Emery   HNS   , 1894:225;. new synonymy.

Cyphomyrmex rimosus var. fusculus Emery   HNS   , 1922:342.

Cyphomyrmex rimosus subsp. curiapensis Weber   HNS   , 1938:190;;.

Cyphomyrmex rimosus subsp. cochunae Kuszenov   HNS   , 1949:4 39- 41.. new synonymy.

We have examined the syntypes of C. rimosus   HNS   , a worker and three males, in the MIZS. Morphologically they are identical to the form described by Emery (1894) as var. fuscus   HNS   . The worker syntype of C. rimosus   HNS   , here designated the lectotype, is callow and it is probably for that reason that Emery described normally-coloured workers as var. fuscus   HNS   . Emery had earlier (1893) examined the syntypes of C. rimosus   HNS   and so had a clear idea of the appearance of the worker; the var. fuscus   HNS   was distinguished only by its darker colour.

Cataulacus deformis   HNS   is usually listed as a synonym of C. minutus   HNS   . The name is a misspelling of F. Smith's Meranoplus difformis   HNS   . Roger introduced this variant spelling when he declared that Mayr's minutus   HNS   was the same as 'deformis'. It is an arguable point, and a trivial one, but we believe that it is most appropriate to maintain the difformis   HNS   - deformis   HNS   link.

Weber (1958) established the synonymy of C.r. curiapensis   HNS   with C. fuscus   HNS   . Kusnezov's subspecies was described as a simple colour variant. Although we have seen no type material of this form, we find nothing in the original description to suggest that it is anything other than what it appears to be: an insignificant colour form not worthy of formal recognition. Previous records for C. rimosus   HNS   are from Argentina, Brazil, the Guianas, and Venezuela.

This species has been introduced and is established in the south-eastern United States. We have seen the following specimens: Alabama: Baldwin Co, Gulf State Park, 16 Apr. 1950 (E.O. Wilson; USNM). Mobile Co, Mobile, 6 May 1950 (E.O. Wilson; LACM); Mobile, 26 Jan. 1950 (A. J. Graham; USNM), in abandoned fire ant mound. County unknown, Cottage Hill, 2 Dec. 1949 (J. M. Coarsell; USNM). florida: Alachua Co, near Gainesville airport, 11 Nov. 1981 (J.C. Trager; JCT, LACM), in disturbed flatwood; La Crosse, 1 July 1981 Q.C. Trager; JCT, LACM), in pasture; Archer Road Lab., Gainesville, 16 June 1984 QC. Trager; JCT, LACM), under boards 2 colonies). Highlands Co, Archbold Biological Station. Price Tract, 10 Oct. 1981 (J.C. Trager; JCT, LACM), in rotting branch on ground; Highlands Hammock State Park, 7 Sept. 1981 R.K. Snelling; LACM), in mowed grass area adjacent to forest. Leon Co, Tallahassee, 10 Jan. 1 98 3 G.B. Marshall; LACM), hardwood litter berlesate. Mississippi: Harrison Co, IO miles N. Gulfport, Nov. 1957 H.T. Yanderford; USNM; Lyman, 24 Mar. 1 9 70 (C. H. Craig; USNM), ex fire ant mound..Mates have been taken within nests between 6 May and 1 July.

In addition to the differences cited in the above key, workers of C. rimosus   HNS   may be further differentiated from those of C. minutus   HNS   by the more prominent dorsal mesosomal tubercles; in particular, the anterior mesonotai tubercle is bluntly triangular in C. rimosus   HNS   , rather than very low and obtuse as in C. minutus   HNS   . In C. rimosus   HNS   the metafemur is sometimes angulate at the basal one-third of the ventral surface, but often it is broadly rounded, and there is, at most, a very weak ridge extended distally from the angulation. The metafemur is distinctly angulate in C. minutus   HNS   and an often lamella-like carina extends distally from the angulation.

Females of the two species differ in many of the same features as do their workers, except, of course, those of mesosomal contour. The head width of C. rimosus   HNS   females is 0.75 mm or more; that of C. minutus   HNS   is less than 0.70 mm, usually about 0.67mm. Males of C. rimosus   HNS   are a little larger than those of C. minutus   HNS   (head width, across eyes, 0.73 vs. 0.68 mm), the lateral ocelli are elevated, the occipital tubercle is bluntly spinelike, and the propodeal teeth, although short, are definitely spine-like.

The following biological information has been provided by J.C. Trager for two samples collected 16 June, 1984 in Gainesville:

These ... were under boards in a weedy lot next to my lab. The brood and fungus gardens of the colonies were kept apart but adjacent on grass stolons or compacted grass blades near the center of single nearly round 5-8 cm-diam. chambers, 1-2 cm deep. Males were clustered on the underside of the board (the warmest, driest part of the nest). The insect fragments, grasshopper feces, etc. collected with one series were heaped separately at opposite sides of the periphery of the nest chamber. This rigid compartmentalization of castes and materials is typical of... this ant. [Queens are usually] associated with the brood [and] most often there are 1 or 2 queens per nest, but I've seen 3 or 4 on occasion. Mating flights take place at the first faint light of dawn, following heavy rains alter a dry spell during the summer months.