Crematogaster pygmaea

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Biology
In this and other species belonging to subgenus Orthocrema, a third caste exists that is intermediate in size, weight and morphology between winged queens and workers. These individuals are numerically few in the colonies, and lay many unfertilized eggs that are mostly eaten by larvae. Histology confirmed the lack of a spermatheca, hence sexual reproduction is impossible. Using scanning electron microscopy and ovarian dissections, Peeters et al. (2013) showed that this third caste is a patchwork of queen-like and worker-like traits. It is a soldier caste with a specialized trophic function. These soldiers are produced seasonally in C. pygmaea, not in Crematogaster schimmeri.

Nomenclature

 *  pygmaea. Crematogaster pygmaea Forel, 1904c: 37 (w.) BRAZIL. Combination in C. (Orthocrema): Emery, 1922e: 135. Subspecies of brevispinosa: Forel, 1909a: 259. Revived status as species: Forel, 1912f: 235; Emery, 1922e: 135. Junior synonym of abstinens: Longino, 2003a: 30. Revived from synonymy: Quinet, Hamidi, et al. 2009: 45.

Additional References

 * [[Media:Peeters etal. ASD2013 Orthocrema.pdf|PEETERS, C., LIN, C.-C., QUINET, Y., MARTINS SEGUNDO, G. & BILLEN, J. 2013: Evolution of a soldier caste specialized to lay unfertilized eggs in Crematogaster ants (subgenus Orthocrema). Arthropod Structure & Development 42: 257-264. PDF]]