Ant

The species is part of a complex of closely related and highly variable taxa that can be difficult to distinguish (Kempf, 1966 (1965)). Snelling and Longino (1992)revised the C. rimosus group and split it into five subgroups. The rimosus subgroup contains seven species, including C. rimosus and its close relative C. minutus. Both species occur in Florida, but whereas C. rimosus is argued to be introduced on the grounds that it has spread rapidly since it was first detected, Cyphomyrmex minutus is considered native (Deyrup, 1991). Cyphomyrmex minutus was treated as a junior synonym of C. rimosus prior to the revision of Snelling and Longino (1992), so it is difficult to determine which species earlier studies are referring to. For example, many of the Neotropical and North American records in the literature refer to the more widespread C. minutus (Snelling & Longino, 1992).

Cyphomyrmex rimosus usually live in colonies of less than 100 workers, but colonies of over 300 workers have been observed (Murakami & Higashi, 1997). Most colonies are usually monogynous, but there are reports of some polygynous colonies as well (Murakami & Higashi, 1997; Snelling & Longino, 1992). The fungus gardens are composed of yeasts in the unicellular phase rather than in the multicellular, mycelial phase typical of all other attine gardens (Mehdiabadi & Schultz, 2010). In addition to feeding on the yeast fungus grown in their gardens, C. rimosus is also known to take the nectar and sap of plants (Murakami & Higashi, 1997). The queens are reported to practice monandry and semi-claustral nest founding (Mehdiabadi & Schultz, 2010; Tschinkel, 1987). Nests are frequently simple, shallow, impermanent structures under rocks, logs or any other surface, and the species prefers open habitats. Further details of the natural history of C. rimosus, in is given in Mehdiabadi & Schultz (2010), Murakami & Higashi (1997)and Snelling and Longino (1992).

(Source unkown). Anida en raíces de las plantas, bajo piedras, forrajea entre la hojarasca. Es frecuente en áreas ocupadas por Wasmannia auropunctata. Presente en jardines de las viviendas y sitios húmedos.

English translation: Nests in plant roots, under rocks, foraging among the fallen leaves. It is common in areas occupied by Wasmannia auropunctata. Present in gardens of dwellings and wet locations.

Native Range (Snelling & Longino, 1992). Neotropics. Argentina, Brazil, Guinanas, Venezuala.

Introduced Range. Galapagos: Isabella, Santa Cruz. United States (Snelling & Longino, 1992): Alabama, Florida, Georgia, Mississippi.

Diagnosis among workers of introduced and commonly intercepted ants in the United States. Antenna 11-segmented. Antennal club 2-segmented. Antennal scapes easily extended beyond eye level. Antennal scrobe present and well developed. Eyes medium to large (greater than 5 facets) but distinctly less than half head length. Eyes located below antennal scrobe near midline of head. Frontal lobes obscure face outline between mandible and eye. Posterolateral corners of head unarmed, without spines. Mandibles triangular. Pronotal spines absent. Propodeum lacking spines or teeth, but tubercles are present. Waist 2-segmented. Spongiform not attached to any portion of waist. Dull brown to blackish brown. Surfaces with appressed scale-like hairs.

In the United States, C. rimosus is most likely confused with C. minutus. Snelling and Longino (1992) separate the two species by the following characters. The head width of C. rimosus is greater (0.62 mm vs. 0.56 mm), and in C. rimosus the hairs on first gastral tergite are not completely appressed and separated by less than their own lengths whereas those of C. minutus are closely appressed and usually separated by more than their own lengths.

Among other introduced and commonly intercepted ants in the United States, C. rimosus can be distinguished the enlarged frontal lobes that obscure the lateral margins of the face, 11-segmented antenna, deep antennal scrobes, indistinct antennal club, and lack of propodeal spines. The antennal scrobes and lack of spines separates C. rimosus from other attine genera (Acromyrmex and Atta). Cephalotes species also have enlarged frontal lobes that obscure the lateral face margins, but C. rimosus can be distinguished from them by the eyes which are placed below antennal scrobe near midline of head (as opposed to at or near apex of antennal scrobe in Cephalotes).

Cyphomyrmex rimosus is a small dull brown to blackish brown ant with deep antennal scrobes, enlarged frontal lobes that obscure the lateral margins of the face, no propodeal spines, an apedunculate petiole, tubercles on the mesosoma, and appressed scale-like hairs. These ants are sometimes difficult to detect on account of their small size, slow movement and tendency to become immobile and even feign death when disturbed. Cyphomyrmex rimosus has a monomorphic worker caste and is considered one of the ‘lower’ attines and cultivates fungus gardens grown on scavenged vegetable matter, dead insects and insect fras. The species is native to the Neotropics, but has established introduced populations in the southern United States and the Galapagos islands. It is not considered a significant pest species in its native or introduced range.

Cryptocerus rimosus Spinola, 1851b: 49 (w.m.) BRAZIL. Neotropic. AntCat AntWiki HOL

Taxonomic history

[Also described as new by Spinola, 1853: 65.].Emery, 1894d PDF: 224 (q.); Wheeler, 1949 PDF: 668 (l.).Combination in Cyphomyrmex: Emery, 1893j PDF: 2.Combination in Atta (Cyphomyrmex): Forel, 1912f PDF: 188.Combination in Cyphomyrmex: Bruch, 1914 PDF: 217.Senior synonym of Cyphomyrmex difformis: Forel, 1893h PDF: 607; Emery, 1894d PDF: 224.Senior synonym of Cyphomyrmex cochunae, Cyphomyrmex fuscus (and its junior synonyms Cyphomyrmex curiapensis, Cyphomyrmex fuscula): Snelling & Longino, 1992 PDF: 491.See also: Smith, 1979: 1410.

[[ worker ]], Ile de Coco (Alfaroi, evidemment importee.

Alto Paraná , Caaguazú (MZSP). Literature records: Canindeyú , “Paraguay” (s. loc.) (Emery 1894a, Fowler 1981).

(No. 50 a a 50 r). [[ worker ]] [[ queen ]] [[ male ]].

(50). Common, in open or shady ground. Communities of four or live to twenty - rarely larger - to one hundred individuals. The formicarium is a simple cavity under a stone or stick, at the roots of grass, or occasionally in rotten wood. The ants are very sluggish, hardly moving when disturbed. I have not found the workers in beating foliage, and judge that they are nocturnal, and probably terrestrial, in their habits. I have perhaps included more than one species under this number. Those found in a nest are always of. the same colour, or nearly so; and, though the colour may be due to age, it is singular that there should be no variation in a community. There seem also to be differences of size and form; but my object in separating the species is simply to get better notes on them, and of course the work is very roughly done. I have found these ants crawling, towards evening, on the floor of a dark outhouse. They move slowly.

(50 a). Wallilobo (leeward), Nov. 8 th. Open valley near sea-level. Nest under the edge of a stone; an unusually large community. Many grass-seeds were found in the nest.

(50 b). Bowwood Valley, near Kingstown, 800 ft. Open place under stone. Oct. 2 lst.

(50 c). Near Palmyra Estate (leeward), 1000 ft. Nov. 4 th. Shady place near stream; under turf on a rock. A small community. All I could find are in the bottle.

(50 d). Richmond Valley, 1000 ft. Nov. 13 th. Shady banks of stream; under turf on a rock.

(50 e). Wallilobo Valley (leeward), 500 ft. Nov. 8 th. Under sod on a rock.

(50 f). Golden Grove (leeward); open place, 300 ft. Oct. 10 th. Small nest (ten or twelve ants) under a stone ..

(50 g). Forest above Chateaubelais (leeward), 1000 ft. Oct. 11 th. Under a stick.

(50 h). Old Botanical Garden, Kingstown, 500 ft. Oct. 22 nd. Under bark of rotten log.

(50 i). Wallibou (leeward); seaside thickets. Oct. 8 th. From two or three small nests under stones.

(50 j). Near Palmyra Estate (leeward), 1000 ft. Nov. 4 th. Shady banks of stream. Small nest under sod on a rock.

(50 k). Near Cumberland (leeward); open valley, 200 ft. Oct. 10 th. Small nest under a stone.

(501). Various localities. Specimens from different nests.

• (50 m). Petit Bordelle Valley, 1200 ft. Nov. 12 th. Shady banks of stream; under sod on a rock.

(50 n). Brighton Estate, southern end of island. Nov. 17 th. Open place, 500 ft.; under sod on a rock. A community of about a hundred individuals.

(50 o). Hermitage Estate, Cumberland Valley, 1000 ft. Dec. 2 nd. Small nest tinder dry sod on a rock; edge of forest.

(50 p). Windward side, Grand Sable Estate. Jan. 3 rd. Thicket near seashore; side of a rock under earth. A community of about forty workers, with a good many males and females.

(50 q). Windward side; sandy bed of the Dry River; near the sea; ' open land. Jan. 2 nd. Under a stone,

(50 r). Richmond Valley; thick forest, 1100 ft. Dec. 29 th. Male found under rotting leaves, & c.

Cyphomyrmex rimosus , presently taken as a polytypical species, is both the commonest form in the genus and at the same time a residue of classification. The puzzling variability of the complex, which gave rise to a number of infraspecific names in the past, needs a special study, not possible at this time.

Yet I must point out that the infraspecific arrangement for rimosus , as proposed at the beginning of this paper, does not imply a judgement upon the validity of the actually recognized 11 morphs and 6 synonyms. It only serves the purpose of keeping track of these names.

The separation of hamulatus , salvini and transversus as full species, and the return of cochunae and venezuelensis to the rimosus complex are novelties. The former step, i. e. the raising of the three "races" to specific category seems to be justified by morphological and distributional considerations; cochunae , elevated to species level by Kusnezov (1957) does not deserve this rank being probably just a synonym of one of the previously described morphs of rimosus ; venezuelensis did not prove a synonym of transversus , as proposed by Weber (1958), and was put back under rimosus awaiting clarification of its true status.

Dr. Weber did not fail in discovering a flaw in my grouping. The rimosus-group, which I already set up in 1962, did not quite live up to expectations. As a matter of fact, longiscapus and to a lesser degree also wheeleri , costatus and possible allies, do not completely conform to the group definition. While definitely distinct from the strictly homogeneous strigatus-group, they might be set apart as a third group within the genus. This situation has already been recognized in the second part of my Cyphomyrmex revision (Kempf, 1965: 163, 166-7).

Cyphomyrmex rimosus is a species of higher myrmicine in the family Formicidae. It is part of the tribe Attini, or fungus-growing ants.