Lachnomyrmex grandis

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Lachnomyrmex grandis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Lachnomyrmex
Species: L. grandis
Binomial name
Lachnomyrmex grandis
Fernández & Baena, 1997

Feitosa and Brandão (2008) - According to the original description, the Colombian specimens were collected manually while foraging in the vegetation of a 520m elevation wet forest. The Costa Rica material was extracted from sifted litter samples from Atlantic slope to 500m elevation forests (Longino 2007). This species was known previously only by the type series (two workers from Colombia). The study of Costa Rican material revealed new records of this rarely collected species. The presence of this species in Costa Rica and Colombia, suggests that it may probably occur in Panama.

Identification

Feitosa and Brandão (2008) - Comparatively large species (HW ≥ 0.90mm, WL ≥ 1.20mm); metanotal groove broadly impressed; first tergite of gaster with extremely long hairs. Lachnomyrmex grandis is the largest species known for the genus. Besides its size, this species can be separated from the others by the combination of irregular sculpture, metanotal groove broadly impressed, and the presence of very long hairs on the gaster. In some individuals, long hairs occur only on the anterior third, while in other specimens they cover nearly entirely the surface of first gastral tergite.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Colombia (type locality), Costa Rica, Guatemala, Nicaragua.

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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.

  • grandis. Lachnomyrmex grandis Fernández & Baena, 1997: 111, fig. 2 (w.) COLOMBIA. Feitosa & Brandão, 2008: 17 (q.).

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

Description

Worker

Feitosa and Brandão (2008) - Holotype. HL 0.96; HW 0.91; ML 0.38; SL 0.69; EL 0.16; WL 1.28; PSL 0.32; PL 0.49; PPL 0.25; GL 1.18; TL 4.54; CI 95; SI 76; OI 18. Worker. HL 0.94; HW 0.91; ML 0.35; SL 0.69; EL 0.17; WL 1.26; PSL 0.30; PL 0.49; PPL 0.25; GL 1.06; TL 4.35; CI 96; SI 75; OI 19.

Color light to dark reddish brown, with lighter appendages. Body densely covered by vermiculate rugae, forming irregular areolae on promesonotum; rugae somewhat longer and longitudinal on cephalic dorsum, and slightly sparser on mesopleura and lateral surfaces of propodeum; mandibles longitudinally striate, except for the apical and masticatory portions; petiole and postpetiole irregularly rugose. Abundant pilosity; dorsum of petiolar node and postpetiole each with more than 10 long hairs; first gastral tergite bearing extremely long flexuous hairs.

Head longer than broad, with vertexal margin weakly convex; frontal lobes subquadrate; eyes well developed, with about seven facets on maximum diameter. Promesonotum moderately convex in profile; metanotal groove broadly impressed; propodeal spines long and straight; teeth of propodeal lobes well developed, but not surpassing the half-length of propodeal spines. Petiolar node elevated, almost subtriangular in profile, but dorsally rounded, and with the posterior face gently sloped in lateral view; postpetiole dorsally convex and with a discrete anteroventral projection.

Queen

Feitosa and Brandão (2008) - HL 1.04; HW 0.99; ML 0.41; SL 0.72; EL 0.26; WL 1.51; PSL 0.32; PP 0.63; PPL 0.31; GL 1.52; TL 5.43; CI 95; SI 73; OI 26.

Similar to worker. Head and pronotum strongly areolate-rugose; mesopleura and lateral faces of propodeum longitudinally rugose. Eyes with around 16 facets at maximum diameter. Propodeal spines shorter than in the conspecific workers. Petiolar node relatively low

Etymology

Feitosa and Brandão (2008) - The name refers to the relative large size of this species. From Latin, grandis: large.

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.
  • Fernández, F.; Baena, M. L. 1997. Hormigas de Colombia VII: nuevas especies de los géneros Lachnomyrmex Wheeler y Megalomyrmex Forel (Hymenoptera: Formicidae). Caldasia 19: 109-114 (page 111, fig. 2 worker described)