Camponotus femoratus

This species and its New World congener Camponotus irritabilis have a reputation as some of the world's most aggressive ant species. Their mandibles can readily break the skin of an unwary or unlucky myrmecologist, and the ants add to this discomfort by spraying the cut with formic acid. An individual worker defending itself like this is mildly annoying. . . the en mass attacks this species deliver are very uncomfortable. Camponotus femoratus and Crematogaster levior live together in ant gardens. Dejean et al. (2018) found this territorially-dominant arboreal-ant species association inhabited 1/5 of the tree canopies they sampled in an Amazonian forest.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, Ecuador, French Guiana, Guyana, Peru, Suriname, Trinidad and Tobago, Venezuela.

Biology
Leal et al. (2017) - Crematogaster levior and Camponotus femoratus are common in Amazonian ant gardens and often occur nesting together. It is known that the latter aggressively defends its nesting location, i.e., the ant garden, while the former does not. Crematogaster levior are able to forage both on the forest understory and on the forest ground, over larger distances from the nest and under more extreme weather conditions (such as at forest edges) in comparison with C. femoratus (Vantaux et al., 2007). Camponotus femoratus forages exclusively in the forest understory for brief periods during the day.

In this study twenty six rainforest ant gardens in forest edge habitat and forest interior locations were examined. Fifteen epiphyte species were found to be incorporated in the ant gardens overall, with from one to five species per nest. The major ant garden difference was a higher incidence of epiphytes with glands, i.e., oil producing or nectar bearing species, in the forest interior. Camponotus femoratus was found to react to chemical compounds indicative of herbivore damage while Crematogaster levior did not. This is consistent with the former providing herbivore protection to the epiphytes it lives with while the latter does not. Along with the differences in foraging potentially limiting the extent of interspecific competition between the two ant species for resources provided by their shared ant garden, Camponotus individuals can get food from Crematogaster workers through trophallaxis (Menzel et al., 2014). Therefore, C. femoratus may co-occur with C. levior due to the additional resource input provided by the latter.

Vicente and Izzo (2017) - Ant gardens occupied by this species were more common and larger in larger forest gaps. Gaps with more open canopies were correlated with a decrease in ground foraging by C. femoratus.

Cuticular Hydrocarbons
Greve et al. (2019) examined the cuticular hydrocarbon profiles of this species and Crematogaster levior. These two ants are parabiotic (share a nest but maintain separate brood chambers). It had previously been shown that there are two different phenotypes/chemotypes of both species, with no apparent differences in their morphology and ecology (Emery & Tsutsui, 2013; Menzel, Orivel, Kaltenpoth, & Schmitt, 2014). The current study gathered cuticular hydrocarbon data from many colonies across a large area (within French Guiana), and also recorded information about secondary metabolites, morphological traits and genotypes. Analysis of the chemical and genetic data clearly separated each species into two distinct groups. A less distinctive but still relevant difference was noted in the morphological data for each of the two species types. The two C. femoratus forms also showed a distinct ecological pattern, with one being more common in the drier, western half of the area where colonies were sampled and the other more prevalent in the wetter and slightly cooler eastern area of sampling. There was no evidence for any segregation by species group within the mutualistic relationship of these two ants, e.g., the two forms of C. femoratus did not show any preference for associating with either form of C levior.

Nomenclature

 *  femoratus. Formica femorata Fabricius, 1804: 397 (q.) BRAZIL. Emery, 1894c: 174 (w.); Forel, 1904c: 49 (s.). Combination in Camponotus: Roger, 1862c: 284; in C. (Myrmothrix): Forel, 1914a: 269. Junior synonym of rufipes: Roger, 1861b: 164. Revived from synonymy: Mayr, 1863: 14. See also: Hashmi, 1973: 44.