Asphinctanilloides

Small hypogaeic blind ant predators with subterranean legionary habits. Their hypogaeic habits may, in concert with collecting techniques that have vastly undersampled ants with such a lifestyle, explain the paucity of information about these ants. Museum collections hold few specimens of these ants.

Identification
Brandão et al. (1999) - Leptanilloidine ants with the following synapomorphies. Only worker caste known: (1) postpetiole extremely reduced in size, smaller than petiole in profile, with spiracles at the midlength; (2) spiracular plate median connection of the sting apparatus with bilobed anterior region; (3) quadrate plate apodeme wider than body of the plate; (4) fulcral arms absent; (5) basal ridge of sting not visible, furcula of the sting in the shape of an inverted U and weakly sclerotized, lateral wing shaped projections developed.

Similar to Leptanilloides but the continuous profile of the gaster segments, without constrictions, differentiates Asphinctanilloides from Leptanilloides.


 * Mesosoma flat without metanotal groove on dorsum; abdominal segments 5 and 6 (gaster segments 2 and 3) with a distinct, much narrower presclerite and wider postsclerite, resulting in constrictions between abdominal segments 4 and 5 (gaster segments I and 2), and 5 and 6 (gaster segments 2 and 3) . . . . . Leptanilloides
 * Mesosoma flat with a metanotal groove on the dorsum; abdominal segments 5 and 6 without separation into pre and postsclerites and thus without constrictions between abdominal segments 4 and 5, and 5 and 6 . . . . . Asphinctanilloides

Borowiec and Longoni (2011) - Although originally the genus Asphinctanilloides had been differentiated from Leptanilloides by several characters (Brandão et al. 1999a), subsequent descriptions of new taxa somewhat blurred this distinction. At present at least presence of a deep metanotal groove and absence of a constriction between abdominal pre- and postsegments V and VI can be regarded synapomorphic for Asphinctanilloides. Ward and Brady (2009) discussed the subject in detail and noted that differentiation of Asphinctanilloides may render Leptanilloides paraphyletic.

Distribution
Brandão et al. (1999) - Asphinctanilloides is exclusively Neotropical, recorded in central Amazon and in a Eucalyptus plantation, replacing a broad-leaved forest in the Sao Paulo State, south-eastern Brazil.

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



Biology
Anecdotal observations suggest these ants ("Leptanilloidinae" species) behave as army-ant like predators. These ants are likely to be largely subterranean, occasionally coming to the ground surface under debri (rocks, downed wood, etc.) while foraging or to allow mature sexuals (either males only or perhaps males and females) to leave their natal nest. Group predation, frequent colony migrations and synchronized brood cycles may also be part of their life history.

Brandão et al. (1999) - Nothing is known about its biology, except that it was caught in soil samples and in one case on the soil surface, with workers feeding on a dead arthropod.

Nomenclature

 *  ASPHINCTANILLOIDES [Leptanilloidinae]
 * Asphinctanilloides Brandão, Diniz, Agosti & Delabie, 1999: 30. Type-species: Asphinctanilloides anae, by original designation.

Mesosoma not as flat as Leptanilloides, but with a metasternal-propodeal suture visible at sides and a metanotal groove on dorsum of sclerite; propodeal dorsum subequal to declivity, the faces separated by an attenuate angle or continuous; petiole (2nd abdominal segment) as long as high; flange over the metapleural gland sharply pointed posteriorly; postpetiole reduced in size in relation to that of Leptanilloides, always shorter than petiole in lateral view; postpetiole spiracles situated at midlength of segment; gaster profile continuous, without constrictions between segments; spiracular plate median connection of sting apparatus with anterior region with 2 lobes; quadrate plate anterior apodema wider than plate itself; anal plate always triangular with about 25 microtrichia; furcula in shape of an inverted U and weakly sclerotized; lateral wing shaped projections developed.

Etymology
Asphinctus means without constrictions in Greek, referring to the continuous profile of the gaster.