Ishakidris

This monotypic genus is known from a single worker. The specimen was collected from a rainforest litter sample.

Identification
Bolton (1984) - Diagnostic characters which in combination isolate Ishakidris from the workers of all other myrmicine ant genera are as follows.

1. Form and dentition of the massive mandibles

2. Palp formula 2,2.

3. Labrum anteriorly with a pair of elongate digitate lobes.

4. Antennae with 9 segments, the two apical segments forming a strongly defined club.

5. Antennal scrobes deep and extensive, the eye situated ventrolaterally within the scrobal area.

6. Head shield-like, the frontal carinae very widely separated and greatly expanded anteriorly and laterally.

7. Frontal carinae flanking lateral portions of clypeus and forming the anterolateral corners of the head.

8. Mesopleural presumed glandular area present, with subtending open groove.

9. Petiole and postpetiole lacking spongiform or lamellate appendages.

10. Massive longitudinal basal carina present on first gastral sternite.

Distribution
Malaysia: Sarawak

Castes
Known only from the worker caste.

Nomenclature

 *  ISHAKIDRIS [Myrmicinae: Phalacromyrmecini]
 * Ishakidris Bolton, 1984: 374. Type-species: Ishakidris ascitaspis, by original designation.

Diagnosis of worker. Ants belonging to subfamily Myrmicinae. Mandibles massively constructed and in profile the convex apical (masticatory) margin almost at a right-angle to the long axis of the head. Mandibles serially dentate and opposable, with 12 teeth on each apical margin and with the teeth alternately larger and smaller from base to apex; basal series of teeth larger than apical series and the mandible lacking a basal lamella. Labrum narrowly long-bilobed anteromedially. Palp formula 2,2 (in situ count). Outline shape of head in the form of a shield in full-face view, the occipital corners acute and the margin between them concave except for a shallow median convexity which encloses a translucent area of cuticle. Sides of head shallowly convex and continuous with the frontal carinae, the latter massively expanded anteriorly and laterally, fused to the sides of the clypeus and completely obscuring the lateral parts of the head from full-face view; the expanded portions of the frontal carinae semitranslucent. Clypeus broad and broadly inserted between the antennal articulations, the median portion of the anterior free margin evenly convex and prominent. Sites of the antennal insertions showing through the expanded flanges of the frontal carinae in full-face view as a pair of blister-like areas close to the anterior margin of the head and abutting the lateral clypeal margins. Antennae with 9 segments, the apical club of 2 segments. Head in profile with deep antennal scrobes, the eyes small and situated posteriorly within the scrobal area close to the ventrolateral margin. Ventrolateral margin of head delimited by a sharp longitudinal carina on each side which runs from the ventral base of the mandibular insertion to the posterior cuticular lug or flange at the occipital corner. Ventral surface of head with a broadly convex median bulge or tumulus. Alitrunk fused, without sutures, the pronotum marginate anteriorly and the sides marginate throughout their length. In profile the propodeal dorsum sloping downwards posteriorly to the triangular laminate propodeal spines, which themselves are subtended by, and partially fused with, a broad infradental lamella on each side. Orifice of propodeal spiracle circular, situated close to the posterior margin adjacent to the narrowest point of the propodeal infradental lamellae. Mesopleuron excavated anterodorsally just posterior to the posteroventral corner of the pronotal laterotergite, the excavated area containing a semicircular patch of thin cuticle upon which (or embedded in which) are a series of radially arranged fine hairs or cuticular processes. From this presumably glandular organ a shallow open groove extends posteroventrally, ending in a slit-like impression at the margin of the mesopleuron. In dorsal view the pronotum much broader than the mesonotum and propodeum, the last two separated by a low but sharp transverse carina. Petiole curved-clavate in profile, with a long anterior peduncle and a long low node. Anterodorsal angle of node blunt but well developed, the dorsum of the node merging evenly with the shallowly sloping posterior face, without a developed posterodorsal angle. Petiolar spiracle small, situated at about the midlength of the peduncle. Ventral process of petiole a low laminar crest which runs the length of the segment. In ventral view the process seen to be double and narrowly V-shaped, with a laminar crest ventrolaterally on each side of the peduncle diverging posteriorly and meeting anteriorly close to the insertion. First gastral tergite without a transverse lamellate or spongiform crest basally, the petiole, postpetiole and gaster lacking spongiform appendages. First gastral sternite basally with a very conspicuous broad median flat-topped longitudinal crest which fits between the ventrolateral flanges of the petiole and the postpetiolar laterosternal lobes and restricts the degree of anterior flexion of the gaster.