Myrmecia pyriformis

Myrmecia pyriformis is a nocturnal forager whose activity outside the nest is largely restricted to night. Most foragers make only one foraging journey per night, leaving the nest individually at dusk to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, but individuals who capture prey often make multiple trips during the night. Foragers imbibe liquid food while abroad and likely share these resources via trophallaxis once within the nest. (Reid et al., 2013; Narendra et al., 2013)

Colonies can have either a normal, dealate queen or survive without a morphological queen (Dietemann et al., 2004). When the queen is absent selected workers (gamergates) are able to reproduce and maintain the colony. A colony collected in 1998 without a queen continued to produce workers for the next three years (Sanetra, 2011). Queens generally mate with multiple males, estimated to be 2.6 on average, and when gamerates are present there are generally more than one (Sanetra, 2011).

Identification Keys including this Taxon

 * Key to Australian Myrmecia Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Myrmecia pyriformis is a nocturnal forager. Most foragers make only one foraging journey per night, leaving the nest individually in a narrow light-window in the evening twilight to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, while few attempt to return to the nest throughout the night (mainly those that are returning with prey). Activity during the night varies with moon illumination, likely due to changes in light levels which influence navigation to and from the nest. As light levels drop, ants pause for longer, walk more slowly, the success in finding the nest is reduced and their paths became less straight. In both bright and dark conditions ants rely predominantly on visual landmark information for navigation and landmark guidance becomes less reliable at low light conditions. It is likely that poor navigational efficiency at low light levels cause the majority of foragers to restrict navigational tasks to the twilight periods, where sufficient navigational information is available (Reid et al., 2013; Narendra et al., 2013)

Castes
Myrmecia pyriformis workers are markedly polymorphic in size; minor workers are almost half the size of majors. All workers have a spermatheca, and 3 gamergates (intermediate in size) were found in one orphaned colony (Dietemann et al. 2004).



Nomenclature

 *  pyriformis. Myrmecia pyriformis Smith, F. 1858b: 144, pl. 10, figs. 1-6 (w.q.m.) AUSTRALIA. Wheeler, G.C. & Wheeler, J. 1971d: 252 (l.); Imai, Crozier & Taylor, 1977: 345 (k.). Subspecies of forficata: Forel, 1910b: 2. Revived status as species: Clark, 1927: 36. Senior synonym of sanguinea: Brown, 1953j: 9. See also: Crawley, 1926: 377; Clark, 1951: 99.
 * sanguinea. Myrmecia sanguinea Smith, F. 1858b: 148 (w.) AUSTRALIA (Tasmania). Mayr, 1876: 94 (q.); Forel, 1910b: 3 (m.); Wheeler, G.C. & Wheeler, J. 1952a: 112 (l.). Junior synonym of forficata: Clark, 1951: 93; of pyriformis: Brown, 1953j: 9. See also: Crawley, 1926: 378.