Myrmecia

Heterick (2009) - Myrmecia are principally predators, but also garner nectar and plant juices (Shattuck 1999). The sting of at least some of these species can be dangerous, even life threatening to people who have a sensitivity to hymenopteran (i.e. bee, ant and wasp) venoms (Street et al. 1994).

Identification
This genus has been divided into a number of species groups.

Vision and activity schedules
With more than 3000 facets in each eye, Myrmecia have the second largest eyes in the ant world (Greiner et al. 2007) and are unusually responsive to moving visual targets. Workers of different species range from diurnal, diurnal-crepuscular, crepuscular-nocturnal to nocturnal. However the activity times of conspecific winged sexuals do not always match. This behavioural diversity correlates with interspecific and caste-specific differences in compound eyes and ocelli (Narendra et al. 2010). Ajay Narendra has studied vision and navigation in the nocturnal Myrmecia pyriformis (see references therein).

Mating biology
Studied in four species by Narendra et al. 2011 - Sexuals walk out of natal nests, climb the nearest tree and fly off from the tips of branches (Myrmecia croslandi), or walk away (Myrmecia tarsata) or fly from the vicinity of the nest (Myrmecia nigriceps and Myrmecia pyriformis). Mating in all species occurred on hilltops. We recorded 18 matings in M. croslandi, six in M. tarsata and 23 in M. nigriceps. We did not witness mating in M. pyriformis, but are confident that alates did not leave the nest during the night.

Human Health Concerns
The stings of one species group of Myrmecia (the M. pilosula group) can cause a strong anaphylactic reaction in some people. The severity of this reaction can develop over time, with initial stings causing no particular reaction while subsequent stings can have serious consequences. People with known sensitivities to these ants often carry an EpiPen or similar device to counteract the affects of a sting.

Species Uncertain
Unknown species of Myrmecia are hosts for the eucharitid wasps and  (parasites) (Universal Chalcidoidea Database).

Castes


Myrmecia queen.

Queen-worker dimorphism in size is moderate to pronounced, according to species (Peeters 1997). Myrmecia chasei exhibits the largest size dimorphism between winged queens and workers. Several species evolved non-flying queens. Brachypterous (i.e. short-winged) queens and ergatoid (permanently wingless) queens disperse on foot (Clark 1951; Haskins & Haskins 1955). Gamergates (mated, egg-laying workers) were found in one colony of Myrmecia pyriformis that was collected without the dealate queen (Dietemann et al. 2004), but a larger sample of colonies needs to be studied.

In Myrmecia gulosa, 14 colonies contained an average of 992 +/- 551 workers (average+/-standard deviation, range 134–1859), and usually one dealate queen. Workers are polymorphic in size (14-23 mm, from tip of mandibles to gaster end), and this is associated with differences in ovariole numbers (Dietemann et al. 2002). Queens are not much larger than the major workers, but have disproportionately more ovarioles and a 10-fold higher egg-laying rate. (See References.)



Larva


Wheeler and Wheeler describe the larvae of several species of Myrmecia in 1971.

Species Uncertain

 * Myrmecia sp. cf. fulvipes:
 * Myrmecia sp.2:

Nomenclature

 *  MYRMECIA [Myrmeciinae: Myrmeciini]
 * Myrmecia Fabricius, 1804: 423. Type-species: Formica gulosa, by subsequent designation of Shuckard, in Swainson & Shuckard, 1840: 173.
 * Myrmecia senior synonym of Promyrmecia (and its junior synonyms Halmamyrmecia, Pristomyrmecia): Brown, 1953c: 1.
 * HALMAMYRMECIA [junior synonym of Myrmecia]
 * Halmamyrmecia Wheeler, W.M. 1922b: 195 [as subgenus of Myrmecia]. Type-species: Myrmecia pilosula, by original designation.
 * Halmamyrmecia junior synonym of Promyrmecia: Clark, 1927: 37; Clark, 1951: 119.
 * Halmamyrmecia junior synonym of Myrmecia: Brown, 1953j: 1.
 * PRISTOMYRMECIA [junior synonym of Myrmecia]
 * Pristomyrmecia Emery, 1911d: 21 [as subgenus of Myrmecia]. Type-species: Myrmecia mandibularis, by original designation.
 * Pristomyrmecia junior synonym of Promyrmecia: Clark, 1927: 37; Clark, 1951: 119.
 * Pristomyrmecia junior synonym of Myrmecia: Brown, 1953j: 1.
 * PROMYRMECIA [junior synonym of Myrmecia]
 * Promyrmecia Emery, 1911d: 19 [as subgenus of Myrmecia]. Type-species: Myrmecia aberrans, by original designation.
 * Promyrmecia raised to genus: Clark, 1943: 84.
 * Promyrmecia senior synonym of Halmamyrmecia, Pristomyrmecia: Clark, 1927: 37; Clark, 1943: 84; Clark, 1951: 119.
 * Promyrmecia junior synonym of Myrmecia: Brown, 1953j: 1.

Taxonomy

 * Smith, F. 1858a. Catalogue of hymenopterous insects in the collection of the British Museum. Part VI. Formicidae. London: British Museum, 216 pp. (page 143, Myrmecia in Poneridae, Myrmicidae)
 * Swainson W.; Shuckard, W. E. 1840. On the history and natural arrangement of insects. London: Longman, Brown, Green & Longman's, 406 pp. (page 173, Type-species: Formica gulosa, by subsequent designation)
 * Wheeler, W. M. 1910b. Ants: their structure, development and behavior. New York: Columbia University Press, xxv + 663 pp. (page 134, Myrmecia in Ponerinae, Myrmeciini [Myrmecii])
 * Wheeler, W. M. 1922i. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VII. Keys to the genera and subgenera of ants. Bull. Am. Mus. Nat. Hist. 45: 631-710 (page 640, Myrmecia in Ponerinae, Myrmeciini)