Leptanilloides

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 and there are also some oddly disjunct distributions for some species.

Identification
Brandão et al. (1999) - Ants with the following synapomorphies (only worker caste and larvae known): (1) propodeal dorsum at least 2 times longer than declivity; (2) gaster with segments 1 and 2, and 2 and 3 separated by deep incisions.

Similar to Asphinctanilloides.

Alitrunk 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

Alitrunk 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

Distribution
Neotropical.

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) - Leptanilloides is exclusively Neotropical, recorded from the Andean foothills at 440 m in Bolivia and in higher altitudes (> 3200 m and up) in Colombia and Ecuador. The biology is completely unknown, except some indication of army ant life style by the study of L. legionaria larvae. The strong girdling constrictions separating the three visible gastral segments is unique among leptanilloidine ants and a similar situation is only found in the cerapachyine Sphinctomyrmex, which has the armed pygidium not reduced. Although the larvae we have in hand are not well preserved, we found nothing similar to the larval haemolymph structure described by Masuko (1989) in Leptanilla japonica.

Nomenclature

 *  LEPTANILLOIDES [Leptanilloidinae]
 * Leptanilloides Mann, 1923: 13. Type-species: Leptanilloides biconstricta, by original designation.

Worker
Brandão et al. (1999) - Alitrunk flat, with a metathoracic-propodeal suture visible on sides of sclerite that may be represented by a faint depression, but never a groove; propodeal dorsum at least 2 times longer than declivity, the faces separated by an attenuate angle; petiole (2nd abdominal segment) longer than high; postpetiole spiracles situated forward of midlength of the segment; abdominal segments 5 and 6 with a distinct, much narrower presclerites and wider postsclerites, resulting in constrictions between abdominal segments 4 and 5, and 5 and 6 ( Figs 2, 4, 6, 8); spiracular plate median connection of sting apparatus with anterior margin convex or straight; furcula in the shape of an U ( Figs 59, 67) and weakly sclerotized; lateral wing-shaped projections absent; sting with bulb base rounded.

Larva
Brandão et al. (1999) - (description based on larva of Leptanilloides legionaria, see below). First 5 abdominal segments clearly differentiated from another; posterior somites indistinct (Fig. 48). Long (50 μm) unbranched, smooth, slightly curved hairs, and a continuous covering of very small (less than 10 μm) unbranched, smooth, slightly curved to flexuous hairs. Head longer than wide (Fig. 49); genae bulging and frons depressed (Fig. 50); antennae relatively long, almost as long as mandibles, with 2 apical sensillae; labrum circular or heart-shaped in face view, elongate. Mandibles without striae or spinules, their outer border furnished with 6 slender sharp-pointed teeth; apical and subapical teeth longer than remaining (Figs 49, 51). Maxillae without paxiliform or digitiform palp, with apical sensillae.