Zasphinctus

Zasphinctus is a moderately speciose lineage of specialized ant predators, most prominent in Australia.

Identification
Diagnosis. Worker. The workers of Zasphinctus are ants of variable size, color, and sculpturation, but always possessing conspicuous girdling constrictions between abdominal segments IV, V, and VI. The eyes absent in most species. Zasphinctus can be distinguished from other lineages with pronounced abdominal constrictions by highly-positioned propodeal spiracles, propodeal lobes present, pygidium large and armed with modified setae, and pronotomesopleural suture fused. See also diagnoses of Eusphinctus and Sphinctomyrmex.

Distribution
The twenty described species of Zasphinctus are distributed throughout Australasia, including New Caledonia and New Guinea, and the Afrotropics. Most species are known from Australia, with only three taxa described from Africa. Recently a species has been described from Thailand (Jaitrong et al. 2016), and unidentified Zasphinctus males are also known from Myanmar (author’s unpublished observations).

Species richness
Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data



Biology
Wilson provided notes on the biology of Zasphinctus caledonicus from New Caledonia and Z. steinheili from Australia. The former was observed raiding a nest of Stigmacros ants in the field, and the latter was feeding on ant brood of several species in the laboratory. Both were reported to have colonies containing multiple ergatoid gynes and synchronized brood. Buschinger et al. (1990) studied a species related to Z. steinheili in more detail under laboratory conditions. They largely confirmed Wilson’s preliminary observations and further demonstrated functional polygyny, since most dissected queens were fertilized with well-developed ovaries. The ants would indeed take brood of several ant species, including European forms, but the colonies ceased producing new eggs after two brood cycles were completed and thereafter slowly declined. Briese (1984) described a nest evacuation response in a Monomorium species raided by Zasphinctus in Australia. Hölldobler et al. (1996) described the metatibial gland of Z. steinheili.

Nomenclature

 *  ZASPHINCTUS  [Dorylinae]
 * Zasphinctus Wheeler, W.M. 1918a: 219 [as subgenus of Eusphinctus]. Type-species: Sphinctomyrmex turneri, by monotypy.
 * Zasphinctus junior synonym of Sphinctomyrmex: Brown, 1975: 31.
 * Zasphinctus as genus: Borowiec, 2016: 237.