Cardiocondyla kagutsuchi

Seifert (2003) - K. Yamauchi (pers comm. 2001) reported for all six of his study sites on Okinawa, in Malaysia, and in Indonesia that this species nested in shallow soil in open, disturbed areas with bare or weakly herbaceous ground.

Identification
Seifert (2003) - A member of the Cardiocondyla nuda group. Cardiocondyla kagutsuchi shows a high structural and morphometric similarity to Cardiocondyla mauritanica and both are undoubtedly sister species. Cardiocondyla kagutsuchi is maintained here as species though it may represent only the SE Palaearctic-Indo-Malayan population of C. mauritanica, which has shorter spines, a lower petiole, a narrower postpetiole, a longer scape, and longer gaster pubescence.

Distribution
This species is certainly of Indo-Malayan origin and, according to the close morphological proximity and mtDNA phylogeny, its closest relative is Cardiocondyla strigifrons. The distributional areas of C. kagutsuchi and C. strigifrons overlap considerably and no large differences in distribution are apparent. (Seifert et al., 2017)

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Guam, Indonesia, Kiribati, Malaysia, Marshall Islands, Micronesia (Federated States of), New Guinea, Northern Mariana Islands, Palau, Philippines, Solomon Islands. Oriental Region: Bhutan, India, Nepal, Thailand, Vietnam. Palaearctic Region: China, Japan.

Biology
Seifert (2003) - Terayama (1999) and Yamauchi (pers comm., July 2000) stated that C. kagutsuchi from Japan and Okinawa (=Cardiocondyla nuda sensu Terayama & al. 1992, Terayama 1999) had a chromosome number of 2n = 28 (males n = 1 4) and only ergatoid males without a promesonotal suture. A restricted local population (= Cardiocondyla sp. 4 Terayama & al. 1992 = C. kagutsuchi Terayama 1999) from Omoto-dake, a small area on the Ishigaki island / Okinawa islands, was reported to have 2n = 27 (males n = 13) and to produce both alate and ergatoid males, the latter of which were said to have a distinct promesonotal suture. These chromosomal and demographic differences prompted Terayama (1999) to consider both populations as heterospecific. However, an accidental nature of the observed differences cannot be excluded. Furthermore the karyotype differences must not necessarily generate reproductive isolation since a correct meiotic pairing of a fused with two homologous unfused chromosomes and a correct subsequent disjunction to give balanced gametes i s possible. The high morphologic similarity of both populations (Tab. 3) is used here as argument to consider them as conspecific as long as the consistency of the karyotype differences and their possible consequences on reproductive isolation is not reasonably demonstrated. If a heterospecifity could be shown, C. nuda sensu Terayama & al. 1992 must be described as new species for reasons of its striking distinctness from C. nuda (Mayr, 1866).

Nomenclature

 *  kagutsuchi. Cardiocondyla kagutsuchi Terayama, 1999d: 100, figs. 1-9 (w.q.m. ergatoid m.) JAPAN. See also: Seifert, 2003a: 252.

Worker
Seifert (2003) - Head elongated, CL/CW 1.182. Postocular index large, PoOc/CL 0.445. Eyes relatively small, EYE 0.230. Frontal carinae immediately caudal of FRS level parallel or very slightly converging. Foveolae on vertex without interspaces, deeply impressed, with 15 - 21 mm diameter, and with inner corona (flat tubercle) of 7 - 9 mm diameter. Longitudinal sculpture on vertex reduced; only frontal laminae, clypeus, and narrow area on anteromedian vertex finely longitudinally carinulate; weak semicircular rugosity is present around antennal fossae. Lateral area of mesosoma on whole surface regularly and strongly microreticulate; longitudinal sculpture except for 4 weak and short carinulae on metapleuron entirely absent; dorsal promesonotum with more irregular reticulum, whose meshes having twice the diameter than those on lateral area of mesosoma. Whole surface of petiole and postpetiole shining, but with very fine microreticulum. Cuticular surface of first gaster tergite shining and almost without microsculpture. Metanotal groove more or less shallow. Propodeal spines reduced to blunt dents. Petiole profile as in Cardiocondyla mauritanica, except for slender peduncle. Petiole node slightly longer than wide. Postpetiole narrower than in C. mauritanica; in dorsal view with distinctly angulate sides and straight anterior margin that is clearly shorter than posterior margin; differing from C. strigifrons by PPW/PPL 1.231 ± 0.029 [1.191 - 1.274] (n = 7); postpetiolar sternite flat. Colour polymorphism: most frequent light morphs with a yellowish to medium brown mesosoma and waist, head a little darker, gaster blackish brown, and antennal club dark brown; rarer dark morphs (Philippines) with blackish brown head and gaster and dark brown mesosoma and waist.

Queen
Seifert (2003) - Head of medium length, CL/CW 1.165. Scape longer than in Cardiocondyla mauritanica, SL/CS 0.807. Postocular index large, PoOc/CL 0.436. Occipital margin more or less straight. Frontal carinae parallel. Foveolae on vertex without interspaces, deeply impressed, with 17 - 19 mm diameter, and with inner corona or flat tubercle of 7 - 9 mm diameter. Longitudinal sculpture on vertex reduced; only frontal laminae, clypeus, and a narrow stripe on anteromedian area of vertex longitudinally carinulate; weak semicircular rugosity present around antennal fossae. Whole dorsal area of mesosoma densely and deeply foveolate-reticulate; lateral area of metapleuron with 6 - 8 longitudinal carinulae. Postpetiole notably foveolate, petiole only weakly sculptured. Spines very short. Shape of waist similar to C. mauritanica but petiolar peduncle more slender. Postpetiole with two anteroventral longitudinal carinulae and significantly lower than petiole: PEH/PPH 1.145 ± 0.045 [1.061, 1.227]. Postpetiole narrower than in C. mauritanica: PPW/CS 0.503. Pubescence longer and denser than in C. mauritanica. More or less concolourous dark to medium brown.

Type Material
Seifert (2003) - Ishigaki Island /Okinawa /Japan) [types investigated]. 6 worker paratypes labelled “Cardiocondyla kagutsuchi Terayama, 1999 \ Paratype \ Omoto-dake, Ishigaki-jima, Okinawa Pref.\ VII 1988, K. Yamauchi leg.”,.