Myrmelachista guyanensis

Every Ant Tells a Story - And Scientists Explain Their Stories Here
Jump to navigation Jump to search
Myrmelachista guyanensis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Formicinae
Tribe: Myrmelachistini
Genus: Myrmelachista
Species: M. guyanensis
Binomial name
Myrmelachista guyanensis
Wheeler, W.M., 1934

Myrmelachista guyanensis jtlc000005278 p 1 high.jpg

Myrmelachista guyanensis jtlc000005278 d 1 high.jpg

Specimen Labels

Wheeler (1934) collected the types from "tenuous, anastomosing galleries in dead twigs and branches."


Worker with nine antennal segments. See Longino's comments regarding Myrmelachista of South America.


Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil, French Guiana, Guyana (type locality), Suriname.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb




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

  • guyanensis. Myrmelachista guyanensis Wheeler, W.M. 1934g: 198 (w.q.) GUYANA.

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



Length 1.3-2 mm.

Head subrectangular, rather flat, slightly longer than broad and slightly narrower in front than behind, with feebly concave posterior and feebly convex lateral borders. Eyes small, flat, slightly in front of the middle of the sides. Mandibles stout, convex, 5-toothed, the median tooth minute. Clypeus convex in the middle, its anterior border sinuate on each side, rounded, projecting and crenulate in the middle and sometimes bearing two closely approximated denticles in the position of the single denticle of other species. Frontal area rather distinct, flat and triangular. Antennae short; scapes curved and somewhat flattened at the base, extending about twice their greatest diameter beyond the posterior orbits; joints 2-5 of the funiculus subequal, strongly transverse, two basal joints of club subequal, together somewhat shorter than the terminal joint. Thorax of the usual shape but rather depressed above; mesoepinotal constriction short and rather feeble in profile, deep on the sides; metaepinotal suture distinct but the metanotal spiracles not projecting; base of epinotum flattened, straight in profile, longer than the very sloping declivity. Petiole with distinct posterior peduncle; scale slightly inclined forward, narrow below, widening above, with slightly convex sides and feebly but distinctly excised, though blunt superior border, so that in profile it is nearly as thick above as below.

Very smooth and shining, minutely and sparsely punctate; mandibles finely punctate-reticulate at the tips; metanotum more opaque, reticulate-rugulose.

Erect hairs and pubescence pale, whitish; the former very scarce, confined to the clypeus and posterior borders of the gastric segments; the latter sparse, appressed, moderately long on the head, thorax and gaster, very short and dilute on the legs and antennae.

Castaneous brown; thorax alone or both head and thorax sometimes paler and more reddish brown; cheeks and clypeus yellowish brown; mandibles, antennae, tibiae, articulations of legs, sutures of thorax and posterior borders of gastric segments brownish yellow; mandibular teeth black; antennal clubs slightly darker than the bases of the funiculi but not infuscated.


Length 3-3.3 mm.

Head like that of the worker in being distinctly narrower anteriorly, but suboblong, one and one-fourth times as long as broad, with straight sides and posterior border. Eyes larger, flat, placed more anteriorly; ocelli small, widely separated. Anterior clypeal border broader, less projecting and more nearly straight, crenulate or with two minute, closely approximated median denticles. Thorax broader than the head, twice as long as broad, much flattened, especially in the region of the mesonotum, which is large, subhexagonal, as broad as long; epinotum low, its dorsal surface very feebly convex, sloping, without distinct base and declivity. Petiolar scale thicker, stouter, with entire, much more obtuse superior border than in the worker. Gaster elongate-elliptical, as long as the remainder of the body. Wings long, with one long cubital cell and no discoidal cell.

Sculpture, pilosity and color as in the worker, but the mesonotum and scutellum pale brown or brownish yellow. Wings colorless, with pale yellow veins and pterostigma.

Type Material

Described from numerous workers and five females which I took at Kartabo, British Guiana, inhabiting tenuous, anastomosing galleries in dead twigs and branches.

Longino (2006) - Syntype workers, queens: Museum of Comparative Zoology, National Museum of Natural History (USNM syntype worker examined).