Anillomyrma

Eguchi et al. (2009) - K. Eguchi and V.T. Bui collected workers of Anillomyrma decamera in a well-developed dry forest in the southern coastal part of Vietnam, by underground bait-trapping; baits (pork sausage) were buried in sandy soil. On the other hand, J. Caceres, a colleague of D.M. General, collected A. decamera in abandoned agricultural land that had isolated stands of abaca plants (Musaceae: Musa textilis NÉE) and jackfruit trees (Moraceae: Artocarpus heterophyllus LAM.), and was overgrown with tall grasses, upright and creeping bamboos and tree ferns. Ant samples were obtained by sifting a soil core sample taken from a deep sandy loam of volcanic origin. Bolton (1987) collected A. tridens on sandy ground in a lowland rain forest. These facts suggest that the distribution of this species may be affected by soil type. Emery (1901) mentioned that the type material of A. decamera was collected from termite nest(s). Anillomyrma may actively hunt soil invertebrates, including termites, using its well-developed sting to envenomate prey, and it may also scavenge animal matter under the ground. Bolton (1987) tentatively suggested that A. tridens is nomadic. These scattered observations may help us to develop collecting and observing methods for these mysterious ant species.

Identification
The eyes are absent. The body is small and thin (less than 2.8 mm long) and uniform pale yellow in color. Similar to Solenopsis but differs in having a three-segmented rather than two-segmented antennal club and in the complete lack of eyes. Solenopsis have small eyes. Also similar to Leptanilla because of their elongate body and lack of eyes. Differ by the presence of frontal lobes that partially cover the antennal sockets. Similar to Dolopomyrmex (United States) but Anillomyrma lacks the median clypeal seta. (Shattuck 1999 and Eguchi et al. 2009)

Workers of the genus are recognised by the following features: 10-segmented antennae; postpetiole attached to top of anterior face of first gastral segment (Bolton, 1994; Eguchi et al., 2010; Hosoishi et al., 2015).

Castes
Known only from the worker caste.

Nomenclature

 *  ANILLOMYRMA [Myrmicinae: Solenopsidini]
 * Anillomyrma Emery, 1913b: 261 [as subgenus of Monomorium]. Type-species: Monomorium decamerum, by monotypy.
 * Anillomyrma raised to genus: Ettershank, 1966: 97.

Worker
Eguchi et al. (2009) - By the combination of the characteristics marked by asterisks, Anillomyrma is distinguished from the other genera of the Solenopsis genus group (sensu Bolton 2003). Worker monomorphic. Body extensively depigmented, weakly sclerotized (easily shrunk when dry-mounted). Head longer than broad, without preoccipital carina; frontal lobe in full-face view only partially concealing torulus, not extending posteriorly as frontal carina; antennal scrobe absent; median portion of clypeus only weakly expanding anteriad and distinctly raised above the level of lateral portions, *not bicarinate laterally below antennal insertion, *narrowly inserted between frontal lobes; median clypeal seta well developed; 1st paracarinal seta well developed; lateral portions of clypeus not forming a raised rim or shield wall in front of antennal insertions; anterior tentorial pit located at the midpoint of antennal insertion and lateral margin of head in full-face view; mandible elongate-triangular, with 3 or 4 distinctly dark-colored teeth on masticatory margin but without any tooth / denticles on basal margin; a short diastema present between the preapical and 3rd teeth; trulleum small and closed; hypostoma without lateral tooth just mesal to each mandibular base; anterior margin of labrum broadly concave medially; *both maxillary and labial palps consisting of two completely separated segments (not consisting of two semi-fused segments, as previously reported ); praementum with a pair of long and simple setae; *antenna 10-segmented, *with | 3-segmented club; antennal segments III - VII each much shorter than broad; segment X much longer than segments VIII and IX combined; segments VIII, IX and X with several sensilla tricodea curvata (arrow in Fig. 7) which are long, thick, simple and appressed; segment X with several sensilla ampullacea (arrow in Fig. 8) [i.e., a peg contained in a bottle-shaped chamber (ampulla) which connects apically with a thin duct; the tube opening on the outer surface of the apex of segment X]; *eye completely absent. Mesosoma in dorsal view moderately constricted between promesonotum and propodeum; promesonotum in lateral view low, almost flat or very weakly convex, without conspicuous humerus; promesonotal suture completely absent dorsally; metanotal groove present dorsally as a weak transverse striation; propodeum neither armed posterodorsally nor carinate posterolaterally; propodeal lobe absent; both mesosternum and metasternum without conspicuous ventral tooth; *propodeal spiracle small, situated at or slightly behind midlength of sides of propodeum; metapleural gland relatively large. *Forecoxa robust, *and much longer than middle and hind coxa; meso- and metatibial spur absent. *Petiolar peduncle long, *without any anteroventral process; *petiolar node long, low and dorsally broadly convex in lateral view; postpetiole much shorter than petiole, in dorsal view almost as broad as or slightly broader than petiolar node, *in lateral view broadly attached to top of anterior face of first gastral segment. Gaster elongate; gastral shoulder absent; *sting strongly developed.