Leptanilla javana

This species was recently transferred from the genus Phaulomyrma, where it was the only known species, to the genus Leptanilla. It is only known from two male specimens.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Indonesia.

Castes
Known only from the male caste.

Nomenclature

 *  javana. Phaulomyrma javana Wheeler, G.C. & Wheeler, E.W. 1930: 193, figs. 1, 2 (m.) INDONESIA (Java). See also: Petersen, 1968: 593.
 * Combination in Leptanilla: Griebenow, 2021: 630.

Type Material

 * Lectotype (designated by Griebenow, 2021: 630): Indonesia: Jawa Barat: male (fragments), Buitenzorg [Bogor], 6.59444S, 106.78917E [error 3 km, estimated with GeoLocate], iii.1907, F. A. G. Muir (MCZ:Ent:31142).
 * Paralectotype (designated by Griebenow, 2021: 630). Same data as for lectotype. No accession code.

Taxonomic Notes
Petersen (1968) - This species was described on the basis of two males from Buitenzorg, Java. The authors found it necessary to create a new genus for it (Phaulomyrma), in which they also included Leptanilla tanit from Tunesia.

The reasons for the erection of the new genus are vague. In the paper it is briefly stated that Phaulomyrma is to be distinguished from Leptanilla by the presence of wing veins and the unusually large genitalia. Further it is seen from the description that the tibial spur formula of Phaulomyrma is 1:2:2 rather than 1:1:2 in Leptanilla (also in L. tanit which was included in the new genus), but in all other features of some generic value the two genera are similar.

This also applies to the wing venation which was regarded as distinctive. New investigations on the wings of Leptanilla show that both Leptanilla and Phaulomyrma  have the same type of venation in the fore wing; in my opinion the original drawing of the wings of Phaulomyrma javana is not quite correct and a correction would probably give an almost the same venation as found in L. tanit, perhaps not quite as reduced.

However, Phaulomyrma  may be retained as a separate genus on the basis of the genital structures if the description and figuring of these are fully correct. The genital capsule of Phaulomyrma javana (figs. 16 A, C) is not unlike that of Leptanilla in the general appearance of the gonocoxites and the inflected gonostyli, but the volsellae are large, plate-like with broadly rounded free margins and without digiti in Phaulomyrma rather than small and probably inflected in Leptanilla and provided with rod-like digiti. There are probably other differences, however, which are not fully recognizable and understandable on the basis of the descriptions and figures alone.

Leptanilla tanit must be included in the genus Leptanilla again. This species has quite normal Leptanilla genitalia, as appears already from the original description, and the results of my examination of type material are confirmative.

Griebenow (2021): Examination of a syntype of P. javana demonstrates that its genitalia are consistent with other sampled male Leptanilla s. str. to the exclusion of males within the Indo-Malayan sister-group of Leptanilla s. str. (Fig. 47). Although the preservation of this specimen (MCZ:Ent:31142) on a slide prevents direct confirmation of stylar articulation, the sharply recurved styli are consistent with the syndrome seen in dried male leptanillines with articulated gonopodites (Kugler 1987; Ward and Sumnicht 2012), indicating that the gonopodites are articulated in P. javana. Contra fig. 2C of Wheeler and Wheeler (1930), the volsellae of P. javana are not discernible in situ (Fig. 47D). If their condition is truly ‘plate-like’, as described by Wheeler and Wheeler (1930, p. 196), the volsellae of P. javana resemble those observed in undescribed Sicilian male morphospecies attributed to Leptanilla (Scupola and Ballarin 2009). Dissection of Anatolian Leptanilla GR03, and Spanish material that closely resembles sequenced males of Leptanilla s. str., demonstrates that the volsellae are likewise lamellate in these morphospecies, having much the same condition as in Leptanilla africana (Baroni Urbani 1977, fig. 37) (not included in this study). Therefore, given the phylogeny of P. javana and its morphological conformity to Leptanilla s. str. there is no justification for maintaining the genus Phaulomyrma.

Male
Length - 1.2 mm.

Head large, about one-fifth of the entire length, slightly longer than broad, somewhat narrowed behind; the posterior border emarginate.

Eyes large, diameter equal to one-third the length of head, prominent, hairy, hemispherical, situated very far forward. Ocelli oval, almost on the vertex.

Antennae thirteen-jointed, half as long as the body; flattened; inserted on the anterior margin of the head; twice as far apart as the distance from the eyes. First segment thickest, one-third as wide as long; second, one-half the length of the first, curved and thickened apically; third, as long as the first; fourth to the thirteenth gradually lengthening until the thirteenth is one-third longer than the first and one-half as wide.

Mandibles minute, labial palpi prominent, one-jointed. Frontal carinae very short and indefinite. Clypeus indistinct.

Thorax at its maximum breadth two-thirds the width of the head, compressed into a somewhat cuneiform shape with the thin edge above. Sutures distinct. Pronotum concealed from above. Dorsal profile in lateral view ascending evenly and obliquely, forming an obtuse angle at the middle of the mesoscutellum, depressed at the sutures of the metanotum, which is rounded. Epinotum rounded.

Anterior leg thickened, spur one-half the length of the first tarsal joint; mesothoracic leg shorter and much more slender than the others; meso- and metathoracic tibiae each with two simple spurs, ttind leg reaching just beyond the tip of the abdomen.

Fore wing three times as long as its greatest width, which is at one-quarter of the length from the apex. Costal and radial veins present, also a cross-vein near the base. Stigma poorly defined. Hind wing very narrow, eight times as long as its greatest width (just beyond the middle) and one-half the length of the fore wing.

Abdomen as wide as the head, one-half the length of the entire insect, and strongly curved so that the sagittae extend forward to the base of the abdomen. Petiole convex below, attenuated anteriorly; posterior third subcylindrical. Node hemispherical.

Hairs abundant except on the genital capsule which is naked; longer on mouth parts and front, and longest on the dorsum of thorax, apex of node, and dorsal tufts on each abdominal segment" more sparse and half as long ventrally. Eyes with numerous very short hairs. Wings conspicuously hairy; the hairs on the surface short, those fringing the margin much longer, decreasing in length toward the base.

Color ferrugino-testaceous, antennae lighter. Legs and mouth-parts light yellowish brown. Integument smooth.

Genitalia large and non-retractile. Lamina annularis slightly compressed. Sagittae widened at the base, the apex extending beyond the stipites; the latter hairy, acuminate, slightly curved, and folded within the lamina annularis. Volsellae thin, plate-like, with broadly rounded free margins. The prongs of the bifurcated subgenital lamina slender, one-fourth as long as the genitalia.

Type Material
Described from two males from Buitenzorg, Java (III-’07), collected by F. Muir. (Ex. coll. W. M. Wheeler.)

References based on Global Ant Biodiversity Informatics

 * Baroni Urbani C. 1977. Materiali per una revisione della sottofamiglia Leptanillinae Emery (Hymenoptera: Formicidae). Entomologica Basiliensia 2: 427-488.
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Chapman, J.W. and S.R. Capco. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monographs of the Institute of Science and Technology (Manila) 1: 1- 327
 * Petersen B. 1968. Some novelties in presumed males of Leptanillinae (Hym., Formicidae). Entomologiske Meddelelser 36: 577-598.
 * Wheeler G. C.; Wheeler E. W. 1930. Two new ants from Java. Psyche (Cambridge) 37: 193-201.
 * Wheeler, G. C.; Wheeler, E. W. 1930. Two new ants from Java. Psyche (Cambridge) 37:193-201.
 * Yasumatsu K. 1960. The occurrence of the subfamily Leptanillinae in Japan (Hymenoptera, Formicidae). Esakia 1:17-20.