Strumigenys ludia group

Strumigenys ludia group Bolton (2000)

Species

Neotropical-Nearctic

Worker Diagnosis

Apical fork of mandible with a single intercalary tooth. Mandible either completely lacking preapical dentition, or with a small preapical tooth that is close to the apicodorsal tooth, or merely with a minute proximal denticle present; preapical dentition may be asymmetrical (see under idiogenes). MI 55-75.

Leading edge of scape with a continuous row of narrowly spatulate hairs that are all curved toward the apex of the scape. Scape subcylindrical or slightly compressed, SI 72-100.

Ventrolateral margin of head not or very shallowly concave in front of eye. Postbuccal groove obsolete, very shallow.

Propodeum with a pair of narrow spines subtended by a narrow lamella on the declivity; without a sharp tooth or spine at base of declivity.

Ventral surface of petiole without spongiform tissue but an extremely fine cuticular carina may be present. Lateral spongiform lobes of petiole and postpetiole small, hardly more than weak expansions at the apices of the respective posterior collars; ventral lobe of postpetiole larger and distinct. Base of first gastral sternite with a narrow to vestigial spongiform pad.

Pilosity. Pronotal humeral hair present, simple or flagellate. Ground-pilosity of head and alitrunk of small spatulate hairs. Longer pilosity varying with species but apicoscrobal hair present and first gastral tergite with numerous curved stout hairs that are remiform or flattened apically; gaster without flagellate hairs.

Sculpture. Head and alitrunk reticulate-punctate, including mesopleuron and metapleuron; with or without overlying rugulae on head and promesonotum. Disc of postpetiole sculptured and first gastral tergite mostly to wholly sculptured.

Notes

Of the three species currently included in this group Strumigenys ludia and Strumigenys idiogenes are certainly related. Strumigenys boneti appears to have come to resemble them by convergence and is therefore grouped here for convenience. Brown (1959a) initially treated boneti with the emeryi group and left it there in his later synopsis (Brown, 1962b). However, the leading edge of the scape in boneti lacks hairs that curve toward the base of the scape, the presence of which is characteristic of the other eight species now known in the emeryi-group, and so it is here excluded from that group.

As for ludia, Brown (1954c) initially placed it in the elongata group and later (Brown, 1962b) grouped it with Strumigenys longispinosa and Strumigenys marginiventris, in an assemblage that he termed the ludia-group, which is probably more accurate. Neither grouping is totally convincing, although derivation from what is here termed the marginiventris group is a distinct possibility.

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028.
Brown, W. L., Jr. 1954c. The neotropical species of the ant genus Strumigenys Fr. Smith: group of elongata Roger. Journal of the New York Entomological Society. 61:189-200.
Brown, W. L., Jr. 1959a. The neotropical species of the ant genus Strumigenys Fr. Smith: group of emeryi Mann. Entomological News. 70:97-104.
Brown, W. L., Jr. 1962b. The neotropical species of the ant genus Strumigenys Fr. Smith: synopsis and keys to the species. Psyche. 69:238-267.