Myrmecia vindex

These ants are visual predators. Typical encounters with even a solitary forager shows that they are a formidable and aggressive species. Nest workers are also always ready to rush out of their mound to attack an intruder (Heterick 2009).

Identification
Heterick (2009) - Myrmecia desertorum, Myrmecia fuscipes, Myrmecia gratiosa, Myrmecia nigriceps and Myrmecia vindex are all large to very large, reddish ants with red, brown or black heads and a black gaster.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Morphology
Myrmecia use their large eyes to locate prey and to find their way back to the nest from their foraging forays. Ogawa et al. (2015) were curious about how complex the color reception in ants may be and identified M. vindex as a good candidate for exploring this topic. They provided evidence about photoreceptors in M. vindex and Myrmecia croslandi that show ants can have sophisticated trichromatic color reception. Their abstract (Ogawa et al. 2015): Ants are thought to be special among Hymenopterans in having only dichromatic colour vision based on two spectrally distinct photoreceptors. Many ants are highly visual animals, however, and use vision extensively for navigation. We show here that two congeneric day- and night-active Australian ants have three spectrally distinct photoreceptor types, potentially supporting trichromatic colour vision. Electroretinogram recordings show the presence of three spectral sensitivities with peaks (lmax) at 370, 450 and 550 nm in the night-active Myrmecia vindex and peaks at 370, 470 and 510 nm in the day-active Myrmecia croslandi. Intracellular electrophysiology on individual photoreceptors confirmed that the night-active M. vindex has three spectral sensitivities with peaks (lmax) at 370, 430 and 550 nm. A large number of the intracellular recordings in the night-active M. vindex show unusually broad-band spectral sensitivities, suggesting that photoreceptors may be coupled. Spectral measurements at different temporal frequencies revealed that the ultraviolet receptors are comparatively slow. We discuss the adaptive significance and the probability of trichromacy in Myrmecia ants in the context of dim light vision and visual navigation.

Nomenclature

 *  vindex. Myrmecia vindex Smith, F. 1858b: 144 (w.) AUSTRALIA. Roger, 1861a: 34 (q.); Clark, 1925b: 143 (q.m.); Wheeler, G.C. & Wheeler, J. 1971d: 254 (l.). Senior synonym of basirufa: Ogata & Taylor, 1991: 1661. See also: Forel, 1907h: 264; Crawley, 1926: 376; Clark, 1951: 67; Douglas & Brown, 1959: 14; Haskins & Haskins, 1974: 258.
 * basirufa. Myrmecia vindex var. basirufa Forel, 1907h: 264 (w.) AUSTRALIA. Clark, 1951: 71 (q.m.). Junior synonym of vindex: Ogata & Taylor, 1991: 1661.

Type Material


Myrmecia vindex

Holotype worker in. Labelled “W. Austral 42/19” and with “Mr Moor” on underside of label.

At some time in the past the head has become detached and is now glued to a label whose underside reads “vindex type Sm.”