Lachnomyrmex regularis

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Lachnomyrmex regularis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Lachnomyrmex
Species: L. regularis
Binomial name
Lachnomyrmex regularis
Feitosa & Brandão, 2008

Lachnomyrmex regularis inbiocri001613693 profile 1.jpg

Lachnomyrmex regularis inbiocri001613693 dorsal 1.jpg

Specimen labels

The only collection of L. regularis was made in northern Costa Rica, at 700m elevation. There is no information on the biology of this species.


Feitosa and Brandão (2008) - Body densely covered by fine and continuous rugae; eyes well developed, with about 10 facets at maximum diameter; dorsum of postpetiole entirely smooth and shining, bearing around four long hairs; gaster distinctly darker than body and with the first tergite completely devoid of long flexuous hairs.

The sculpturation pattern and the presence of a subpostpetiolar projection are similar to Lachnomyrmex haskinsi. However, L. regularis is easily distinguishable by its larger body size, rugae on head dorsum distinctly denser, eyes more developed, postpetiole dorsum entirely smooth, and body color variably brown contrasting with darker gaster.

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: 11.067° to 10.99261°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


Very little is known about the biology of these cryptic ants. Workers are frequently found in leaf litter and soil samples processed in Winklers or Berlese extractors, but these ants are never especially abundant within samples. When a dealate gyne is found associated with workers in 1m2 samples of leaf litter, normally it is found singly, which suggests that colonies are relatively small and apparently monogynic; workers and nests are extremely difficult to spot in the field, because the workers are very slow moving and well camouflaged; if there is any leaf-litter nest structure, it is destroyed during sifting, but our impression is that they do not construct any permanent nidal structure. Species of Lachnomyrmex apparently nest within the leaf litter, inside natural cavities of the superficial soil layers, fallen logs, and rotten wood, as evidenced by the large number of soil-covered individuals collected, from information recorded in specimen label data, and from observations of collectors. Workers forage alone, in the leaf litter and in the low vegetation, occasionally among epiphytes and moss, probably preying on small soft-bodied arthropods and possibly harvesting plant exudates. (Feitosa and Brandao 2008)


Known only from the worker caste.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • regularis. Lachnomyrmex regularis Feitosa & Brandão, 2008: 38, figs. 15, 19 (w.) COSTA RICA.

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



Holotype worker HL 0.84; HW 0.79; ML 0.29; SL 0.55; EL 0.20; WL 0.98; PSL 0.30; PL 0.39; PPL 0.20; GL 1.02; TL 3.73; CI 93; SI 70; OI 26. workers (n=7). HL 0.82–0.90; HW 0.76–0.83; ML 0.25–0.31; SL 0.53–0.58; EL 0.19– 0.22; WL 0.98–1.09; PSL 0.27–0.31; PL 0.38–0.47; PPL 0.17–0.24; GL 0.96–1.10; TL 3.57–4.11; CI 91–93; SI 69–71; OI 25–28.

Color light reddish-brown to dark brown, contrasting with blackish gaster; appendages slightly lighter than body. Head and mesosoma densely covered by continuous, fine rugae, transverse on anterior portion of pronotum, grading to longitudinal on rest of promesonotum, mesopleura, and propodeum; rugae on cephalic dorsum subparallel and exceptionally dense, leaving no spaces among them; mandibles with short longitudinal striae restricted to basal portion; petiole and postpetiole only feebly rugose on lateral faces. Abundant pilosity on head and dorsum of promesonotum; dorsum of petiolar node and postpetiole with about six and four long hairs, respectively; first tergite of gaster entirely devoid of long flexuous hairs.

Head noticeable longer than broad, with vertexal margin weakly convex; frontal lobes somewhat angulate laterally; eyes relatively large, with around 10 facets at greatest diameter. Promesonotum considerably convex in profile, well above propodeum level; metanotal groove relatively narrow and markedly impressed; propodeal spines straight and relatively long; teeth of propodeal lobes widen basally, with about one-third of propodeal spines length. Petiolar node strongly elevated and subtriangular in lateral view; dorsum of postpetiole with a raised prominence medially and a well developed anteroventral projection directed anteriorly.

Type Material

Holotype worker. COSTA RICA: Guanacaste: Estr. Pitilla, 9km S Sta. Cecília, 11º04'N 85º24'O, 6– 19.viii.1993, P. Ríos col., no. INBIOCRI001613693 [INBC]. Paratypes. same data as holotype; no. INBIOCRI001613661 (1 worker) [BMNH]; same data, nos. INBIOCRI001613662/INBIOCRI001613666/INBIOCRI001613673/INBIOCRI001613676 (4 workers) [INBC]; same data, nos. INBIOCRI001613677/INBIOCRI001613681 (2 workers) [MZSP].


This species is named after its regular pattern of body sculpturation in comparison with other Lachnomyrmex species. From Latin, regularis: regular.


  • Feitosa, R.M. & Brandão, C.R.F. 2008. A taxonomic revision of the Neotropical myrmicine ant genus Lachnomyrmex Wheeler (Hymenoptera: Formicidae). Zootaxa 1890, 1-49.

References based on Global Ant Biodiversity Informatics

  • INBio Collection (via Gbif)