ORIGINAL ARTICLE Subterranean species of the ant genus Crematogaster in Asia (Hymenoptera: Formicidae) Shingo HOSOISHI 1 , Seiki YAMANE 2 and Kazuo OGATA 1 1 Institute of Tropical Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 and 2 Department of Earth & Environmental Sciences, Graduate School of Science and Engineering, Kagoshima University, Korimoto 1, Kagoshima, 890-0065 Japan Abstract Three Crematogaster ant species, C.(Orthocrema) javanica Menozzi, C.(O.) myops Forel and C.(O.) masukoi sp. nov., share reduced compound eyes which characterizes them among Asian species of the subgenus Orthocrema. The new species is described based on material from Borneo. It can be distinguished from C. javanica and C. myops by its smooth surface of clypeus and acutely produced subpetiolar process. Reduced compound eyes and yellowish body suggest that these three species are subterranean. Key words: Indonesia, javanica, Malaysia, myops, new species, Orthocrema. INTRODUCTION Several new myrmicine genera and species have recently been discovered from soil core samples (Bolton 1988; Belshaw & Bolton 1994; Eguchi et al. 2006; Eguchi & Bui 2007). Subterranean taxa are infrequently collected and often have distinctive morphological features. They have reduced compound eyes and depigmented yellow- ish body. Subterranean species are poorly known in the genus Crematogaser. The genus Crematogaster is mostly arboreal, but some species belonging to the subgenus Orthocrema are ground-dwelling ants. These ground-dwelling ants are mainly collected from soil and leaf litter samples. The latest checklist (Bolton et al. 2006) counted 153 names (species and subspecies) in the subgenus, com- prising 117 valid names and 36 junior synonyms. In Asia, 14 species and 4 subspecies are known. The sub- genus can be easily distinguished by the following character combinations: (i) 2-segmented antennal club; (ii) petiole with parallel sides; and (iii) postpetiole without median sulcus (Emery 1922; Santschi 1918); but it is difficult to identify specimens to species, and there are many undescribed species. In this paper, we follow the subgeneric classification (Bolton 1995, 2003; Bolton et al.2006) temporarily for the purpose of taxonomic convenience and avoiding new syn- onyms. Menozzi (1935) provided a key to the Orthocrema species of Malesia and New Guinea. His key included only two small-eyed species, C.(O.) javanica Menozzi, 1935 and C. (O.) myops Forel 1911. These two species are unique among the Asian fauna in having compound eyes consisting of approximately six omma- tidia, and can be easily distinguished from other Orthocrema species by this character. In the course of our recent examination of specimens collected from soil samples, we found a third small-eyed Orthocrema species similar to C.(O.) javaniva and C.(O.) myops. We here describe the species and discuss morphological specializations and affinities of small-eyed Orthocrema species. MATERIALS AND METHODS Specimens examined or referred to are deposited in the collections below. Codes for public institutions mainly follow those in Brandão (2000). Correspondence: Shingo Hosoishi, Institute of Tropical Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581 Japan. Email: hosoishi@agr.kyushu-u.ac.jp Received 09 September 2009; accepted 07 March 2010. Entomological Science (2010) 13, 345–350 doi:10.1111/j.1479-8298.2010.00390.x © 2010 The Entomological Society of Japan