Stigmatomma

Stigmatomma was long considered a junior synonym of Amblyopone (see Brown 1960) until it was recently revived (Yoshimura & Fisher, 2012). Members of this genus, as most amblyoponines, are specialised predators, which are thought to hold several ancestral anatomical and behavioural character states (Fisher, 2003). Stigmatomma species are known to live a hypogaeic lifestyle as predators of chilopods (Gotwald & Levieux, 1972) or occasionally other arthropods and in addition, are known as "dracula ants" that feed on their own larvae (Fisher, 2003; Saux et al., 2004). Queens can be observed to perform a form of non-destructive cannibalism by cutting a hole in the larval integument to feed on the exuding hemolymph. This however does not seem to harm the larvae, which continue growing and eventually emerge as normal adults. (Hita Garcia, Wiesel and Fischer 2013)

Identification
Head without mandible rectangular or trapezoidal mesosoma and gaster more or less cylindrical in form; mandibles elongate narrow, pointed and slightly curved at apex, middle to basal part of inner margin of mandible with triangular teeth arranged in two rows, or with more or less bifid teeth arranged in a single row, eye moderate to minute to vestigial, placed at the sides on above or below the mid length of head; antennae 11-12 segmented, filiform, the apex only slightly incrassate. Mesosoma narrower than head, promesonotal suture distinct, mesosoma strongly constricted at promesonotal suture and divided in to almost two equal halves; meso-metanotal sutue effaced; metanotum obliquely truncate posteriorly, basal portion passing into the apical portion by a more or less rounded curve, apical face of metanotum broadened, sides submargined; legs short, robust, tibiae of the posterior legs with two calcaria. Petiole cubical, broadly attached to ABIII, gaster narrow, not wider than the mesosoma, constriction between the basal two segments deep, giving the basal segment a nodiform appearance; sting exserted. (Bharti and Rilta 2015)

Within the United States workers and queens of Stigmatomma are recognized by their long, narrow jaws, set with sharp, triangular teeth. The margin of the clypeus has a row of small teeth, and the petiole is broadly attached to the gaster. Males also have the petiole broadly attached to the gaster, and lack the conspicuous punctures of male Platythyrea, the other poneromorph genus with a broadly attached petiole.

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



Biology
Within the United States most species are found in mesic areas, and forage underground or in litter; species of semiarid regions tend to remain deep in the soil and are seldom observed (Brown 1960). All species appear to be exclusively predatory. The prey is often large arthropods, especially centipedes: at least one species appears to be a specialized predator of geophilomorph centipedes (Gotwald and Levieux 1972). There is evidence that in some cases larvae may be transported to a large, paralyzed prey, rather than bringing the prey to the nest (Brown 1960).

While their primary prey is centipedes, James Trager observed Stigmatomma pallipes workers and larvae under a stone in Missouri USA, feeding on an Elateridae (beetle) larva, which appeared to have been killed by them (fresh, no external damage evident on the larva, except where the larvae were chewing into the intersegmental membranes).

Vietnam - Stigmatomma spp. usually occur in well-developed forests but sometimes in forest edges. They nest under rotting logs, under stones, and in litter and soil. We often found their nests with remnants of small centipedes probably eaten by their larvae. (Eguchi et al. 2014)

Nomenclature

 *  STIGMATOMMA  [Amblyoponinae]
 * Stigmatomma Roger, 1859: 250. Type-species: Stigmatomma denticulatum, by subsequent designation of Bingham, 1903: 36.
 * Stigmatomma junior synonym of Amblyopone: Emery & Forel, 1879: 455; Mayr, 1887: 546.
 * Stigmatomma revived from synonymy: Dalla Torre, 1893: 14.
 * Stigmatomma subgenus of Amblyopone: Forel, 1900c: 55; Clark, 1934b: 27; Brown, 1949c: 87.
 * Stigmatomma revived status as genus: Bingham, 1903: 36; Emery, 1911d: 23; Creighton, 1950a: 31.
 * Stigmatomma senior synonym of Fulakora: Brown, 1949c: 87.
 * Stigmatomma junior synonym of Amblyopone: Brown, 1960a: 155.
 * Stigmatomma revived status as genus: Yoshimura & Fisher, 2012: 17.
 * Stigmatomma senior synonym of Arotropus, Ericapelta, Fulakora, Lithomyrmex: Yoshimura & Fisher, 2012: 17.
 * AROTROPUS [junior synonym of Stigmatomma]
 * Arotropus Provancher, 1881a: 205. Type-species: Arotropus binodosus (junior synonym of Typhlopone pallipes), by monotypy.
 * Arotropus junior synonym of Amblyopone: Provancher, 1887: 240; Brown, 1960a: 155.
 * Arotropus junior synonym of Stigmatomma: Yoshimura & Fisher, 2012: 17.
 * BANNAPONE [junior synonym of Stigmatomma]
 * Bannapone Xu, 2000b: 299. Type-species: Bannapone mulanae, by original designation.
 * Bannapone junior synonym of Stigmatomma: Ward & Fisher, 2016: 691.