Cardiocondyla itsukii

Identification
Seifert et al. (2017) - There is no doubt that species separation in the C. nuda group is difficult. It requires careful consideration of character definitions and the use high-resolution optical and measurement systems. The diagnose presented here uses numerous morphological characters to achieve an acceptable identification error rate.

Meeting the following definition:


 * Discriminant 176.328×PPH - 49.049×CW + 51.521×SP - 59.844×PPW + 6.61 < 0
 * Discriminant 214.193×PLG - 88.759×SP + 57.676×SL - 106.17×PEH - 10.465 > 0
 * Discriminant 319.279×PLG - 49.672×PPW + 133.938×FRS - 177.726×EYE + 91.370×CW - 63.848×SL - 12.955 > 0

where:


 * CW: Maximum cephalic width; the maximum is found usually across and including the eyes, exceptionally posterior of the eyes.


 * EYE: Eye-size - the arithmetic mean of the large (EL) and small diameter (EW).


 * FRS: Distance of the frontal carinae immediately caudal of the posterior intersection points between frontal carinae and the lamellae dorsal of the torulus. If these dorsal lamellae do not laterally surpass the frontal carinae, the deepest point of scape corner pits may be taken as reference line. These pits take up the inner corner of scape base when the scape is fully switched caudad and produce a dark triangular shadow in the lateral frontal lobes immediately posterior of the dorsal lamellae of scape joint capsule (Fig. 1).


 * PEH: Maximum petiole height. The straight section of ventral petiolar profile at node level is the reference line perpendicular to which the maximum height of petiole node is measured at node level.


 * PLG: Mean length of pubescence hairs on dorsum of first gaster tergite as arithmetic mean of at least 7 measurements measured at magnifications of 320x.


 * PPH: Maximum postpetiole height; the lateral suture of dorsal and ventral sclerites is the reference line perpendicular to which the maximum height of postpetiole is measured.


 * PPW: Maximum width of postpetiole.


 * SL: Maximum straight line length of scape excluding the articular condyle given as the arithmetic mean of both scapes.


 * SP: Maximum length of propodeal spines; measured in dorsofrontal view along the long axis of the spine, from spine tip to a line that orthogonal to the long axis and touches the bottom of the interspinal meniscus (Fig. 3). Left and right SP are averaged. This mode of measuring is less ambiguous than other methods but yields higher spine length values in species with reduced spines. This is the case in the dentiform spines found in the C. nuda group where it is difficult to correctly define the long axis. In such cases, the deviation of the assumed spine axes from longitudinal mesosomal axis should not exceed 30°.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Hawaii, Indonesia, Kiribati, Philippines. Malagasy Region: Réunion. Oriental Region: Bhutan, India, Nepal, Sri Lanka, Thailand. Palaearctic Region: China, Japan.

Nomenclature

 *  itsukii. Cardiocondyla itsukii Seifert, Okita & Heinze, 2017: 339, figs. 10-12 (w.q.m.) JAPAN.

The holotype plus 8 paratypes (4 workers, 2 gynes and 2 males) are on three pins labelled "JAP: 34.72297 N, 137.83881 E / Shizuoka Pref. Iwata-shi, 12 m / street margin in rural land/ leg. I. Okita 2010.09.05-81". The pin with the holotype carries a red type label "Holotype (top specimen) / & Paratypes / Cardiocondyla itsukii / Seifert & Okita" and the two pins with paratypes have labels "Paratypes / Cardiocondyla itsukii / Seifert & Okita". These are deposited at SMNG. Five additional paratype workers are deposited at CAS. Furthermore, 120 workers, 86 gynes, and 1 ergatoid male are stored in ethanol at MNEHS.