Lachnomyrmex nordestinus

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

Lachnomyrmex nordestinus casent0173878 profile 1.jpg

Lachnomyrmex nordestinus casent0173878 dorsal 1.jpg

Specimen labels

All known specimens were collected in the leaf litter of the northeastern Brazilian Atlantic Forest (100–800m).

Identification

Feitosa and Brandão (2008) - Promesonotum strongly convex and elevated well above the level of propodeum, in profile; metanotal groove obsolete; apex of propodeal spines slightly curved upwards; teeth of propodeal lobes reduced; dorsum of postpetiole with around six long hairs; first gastral tergite entirely devoid of long flexuous hairs. This species is very similar to Lachnomyrmex amazonicus and Lachnomyrmex victori, but can be readily distinguished mainly by the scarcer pilosity on postpetiole dorsum. Gynes of L. nordestinus can be separated from L. victori by the absence of long flexuous hairs on the dorsum of the first gastral tergite.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

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)

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • nordestinus. Lachnomyrmex nordestinus Feitosa & Brandão, 2008: 29, figs. 11, 18 (w.q.) BRAZIL.

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

Description

Worker

Holotype measurements. HL 0.65; HW 0.65; ML 0.22; SL 0.38; EL 0.13; WL 0.72; PSL 0.19; PL 0.31; PPL 0.13; GL 0.80; TL 2.84; CI 100; SI 59; OI 19. Worker measurements (n=16). HL 0.63–0.74; HW 0.61–0.72; ML 0.20–0.24; SL 0.37–0.46; EL 0.12– 0.14; WL 0.68–0.80; PSL 0.15–0.24; PL 0.30–0.36; PPL 0.11–0.14; GL 0.77–0.93; TL 2.71–3.18; CI 96–100; SI 59–67; OI 19–22.

Color light brown to blackish, contrasting with yellowish appendages and gaster. Body densely covered by vermiculate short rugae, forming irregular areolae on promesonotum dorsum; rugae somewhat longer and longitudinal on head dorsum, and slightly sparser on mesopleura and lateral surfaces of propodeum; mandibles with short longitudinal striae restricted to basal portion; petiole and postpetiole finely and irregularly rugose. Abundant pilosity on head and promesonotum dorsum; dorsum of petiolar node and postpetiole with around 10 and six long flexuous hairs, respectively; first gastral tergite entirely devoid of long hairs. Head as long as broad to slightly longer than broad, with vertexal margin only minimally convex; frontal lobes laterally rounded; eyes with about six facets on maximum diameter. Promesonotum strongly convex in profile, elevated well above the level of propodeum; metanotal groove virtually obsolete; propodeal spines well developed and slightly directed upwards; teeth of propodeal lobes reduced, with approximately one-third of propodeal spines length. Petiolar node moderately elevated and rounded dorsally, with the posterior face weakly sloped in lateral view; postpetiole gently convex dorsally and without ventral processes.

Queen

(n=3). HL 0.71; HW 0.69–0.71; ML 0.21–0.24; SL 0.44–0.46; EL 0.18–0.19; WL 0.90–0.94; PSL 0.19–0.20; PL 0.33–0.38; PPL 0.15–0.16; GL 0.93–0.98; TL 3.27–3.40; CI 98–100; SI 62– 66; OI 25–26.

Differing from the conspecific worker by the larger size of eyes, with about 15 facets at maximum diameter; propodeal spines comparatively shorter and straight apically; petiolar node only feebly elevated; ad dorsum of postpetiole with more than 10 long flexuous hairs.

Type Material

Holotype worker. BRAZIL: Paraíba: João Pessoa, Mata do Buraquinho, 07º08'24S 34º51'33W, 25.vii.2002, R.R. Silva & F. Eberhardt cols, no. 5 Museu de Zoologia da Universidade de Sao Paulo. Paratypes. same data as holotype (1 worker) [MZSP]; BRAZIL: Ceará: Maranguape, viii.2003, Y. Quinet col., no. 80 (2 workers) Universidade Federal do Ceará; same data (1 worker) [MZSP]; Pernambuco: Jaqueira, Usina Colônia, M. do Espelho, 30.vii.2003, A. Bieber & I. Leal cols, no. P.05 (1 gyne) Departamento de Botânica, CCB; Recife, Horto Dois Irmãos, 08º00'32S 34º56'40W, 15–24.vii.2002, R.R. Silva & F. Eberhardt cols, nos. 2/7/13/28/32/34/36/38 (7 workers and 1 gyne) [MZSP]; same data, no. 32 (1 worker) {{[AMNH}}; same data, no. 33 (1 worker) The Natural History Museum; same data, no. 34 (1 worker) California Academy of Sciences; same data, no. 36 (1 worker) Laboratório de Mirmecologia CEPEC / CPDC; same data, no. 38 (1 worker) Museo de Historia Natural, Bogata; Sergipe: Areia Branca, P. E. da Serra de Itabaiana, 10º45'54S 37º19'57W, 19–25.v.2003, R.R. Silva, B.H. Dietz & L.S. Ferreira cols, nos. 10/17/26/30/46/47 (6 workers and 2 gynes) [MZSP]; same data, no. 38 (1 worker) Instituto de Zoologia Agricola; same data, no. 46 (1 worker) National Museum of Natural History; same data, no. 46 (1 worker) William and Emma Mackay.

Etymology

The epithet nordestinus refers to the northeastern Brazil (from Portuguese: Nordeste), the geographical region where this species occurs.

References

  • 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.