Monomorium micula

According to specimen label data this species has been collected in a range of habitats (native veg in rural environment, Casuarina, degraded open woodland, dune). Nests have been noted as being in the ground (dune nest, in two adjacent small nests on sandy track).

Identification
Heterick (2001) - A member of the monomorium group. Monomorium micula can be distinguished from other small, yellow Monomorium by a combination of its large eye and the absence of erect and suberect setae on the dorsum of the body.

Heterick (2009) - One of a trio (also Monomorium disetigerum, Monomorium silaceum) of small, yellow species from drier regions that can often be hard to distinguish from pale Monomorium sydneyense.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Heterick (2001) - This minute, depigmented species is probably quite common in sandy, inland areas of the Australian mainland, but is easily overlooked because of its small size.

Nomenclature

 * . Monomorium micula Heterick, 2001: 407, figs. 37, 122, 138 (w.) AUSTRALIA (South Australia, Queensland, Western Australia).
 * Type-material: holotype worker, 18 paratype workers, 1 paratype ergatoid queen.
 * Type-locality: holotype Australia: South Australia, Ferries-MacDonald Reserve, 27.iv.1969 (P.J.M. Greenslade); paratypes: 4 workers with same data, 3 workers South Australia, Cambrai, 28.i.-1.ii.1972, dune IIb–III (P.J.M. Greenslade), 2 workers South Australia, Cambrai, 18-21.ii.1972, dune IIb (P.J.M. Greenslade), 3 workers South Australia, Cambrai, 21-25.ii.1972, dune III (P.J.M. Greenslade), 1 worker South Australia, Cambrai, 6.iii.1972, dune IV (P.J.M. Greenslade), 4 workers, 1 ergatoid queen South Australia, 12 km. W Emu, Victoria Desert, 5-10.x.1976 (P.J.M. Greenslade), 1 workers South Australia, Koonamore, 24-27.ii.1973 (P.J.M. Greenslade).
 * Type-depositories: ANIC (holotype); ANIC, BMNH, MCZC (paratypes).
 * Status as species: Heterick, 2009: 160.
 * Distribution: Australia.

Worker
Holotype. HML 1.03; HL 0.44; HW 0.36; CeI 82; SL 0.32; SI 90; PW 0.21. Other. HML 0.90-1.11; HL 0.36-0.48; HW 0.32-0.38; Cel 76-89; SL 0.27-0.34; SI 84-1 00; PW 0.16-0.20 (19 measured).

As for the worker of Monomorium sydneyense, but with the following apomorphies.

Head. Frons of head capsule smooth and shining with evenly spaced, appressed setulae. (Viewed laterally) compound eyes set at midline of head capsule; eye large, eye width greater than 1.5x greatest width of antennal scape. Anteromedial clypeal margin straight or slightly emarginate, median clypeal carinae not produced as teeth or denticles. Frontal lobes parallel, sinuate. Mandibles (viewed from front) strap-like with inner and outer edges subparallel, smooth with piliferous punctures.

Alitrunk. Promesonotal sculpture present in form of microreticulation and striolae on and around katepisternum, otherwise promesonotum smooth and shining; dorsal promesonotal face evenly convex; erect and suberect promesonotal setae absent. Dorsal propodeal face flattened, or sloping posteriad, with wedge-shaped flattening or shallow depression that is widest between propodeal angles; processes present as pronounced lamellae formed by extension of metapleural lobes. Declivitous face of propodeum flat. Erect and suberect propodeal setae absent or very sparse; propodeal setulae absent. Propodeal spiracle lateral and about midway between metanotal groove and declivitous face of propodeum.

Petiole and postpetiole. Petiolar node conical, dorsally rounded; sculpture absent, petiolar node smooth and shining. Anteroventral process always present as pronounced spur. Height ratio of petiole to postpetiole near 4:3; height-length ratio of postpetiole near 2: 1 to near 4:3. Sculpture absent on dorsum, at least: postpetiole smooth and shining.

Gaster. Pilosity of first gastral tergite consisting entirely of well-spaced appressed setulae.

General characters. Colour various shades of yellow. Worker caste monomorphic.

Etymology
Latin: “little morsel”.

References based on Global Ant Biodiversity Informatics

 * Heterick B. E. 2001. Revision of the Australian ants of the genus Monomorium (Hymenoptera: Formicidae). Invertebrate Taxonomy 15: 353-459.