A new species of the genus Carebara Westwood, 1840 (Hymenoptera: Formicidae: Myrmecinae) inhabits a cave in Thailand Author Jaitrong, W. Author Pitaktunsakul, P. Author Jantarit, S. text Far Eastern Entomologist 2021 2021-02-03 425 7 20 http://dx.doi.org/10.25221/fee.425.2 journal article 10.25221/fee.425.2 2713-2196 Carebara pygmaea species group DESCRIPTION. Dimorphism in worker caste. Major worker. Head larger than thorax; frons with longitudinal striation; frontal carinae with 3 pairs of erect hairs; mandible relatively short, subtriangular, masticatory margin with 5 teeth (including large apical tooth); antenna 11-segmented with 2-segmented club; antennal scape thin (clavate, its apical portion narrower than or broad as long as antennal segment X); promesonotum in profile view distinctly convex to form a dome; promesonotal suture indistinct; metanotal groove distinct; propodeum distinctly lower than promesonotum; propodeal spine short, usually shorter than its base; petiole, in profile, with long anterior pedicel; postpetiole clearly shorter than petiole; Gastral tergite I clearly large than remaining segments. Minor worker. Head small, smooth and shiny; mandible relatively short, subtriangular, masticatory margin with 5 teeth (including large apical tooth); eye very small, present as a dot; antenna 11-segmented with 2-segmented club; antennal scape thin (clavate, its apical portion narrower than or almost as broad as antennal segments X); promesonotum in profile view convex, smooth and shiny; promesonotal suture absent; metanotal groove distinct; mesopleuron and propodeum largely punctate; propodeal spine absent; petiole, in profile, with long anterior pedicel; postpetiole clearly shorter than petiole; Gastral tergite I clearly large than remaining segments. Dealate geny. Head smaller than mesosoma; frons with longitudinal striation; eye large and convex; three ocelli present on vertex; pronotum in profile placed in vertical, subrectangular, shorter than mesoscutum; masoscutum large, located higher than pronotum, subtrapezoidal, its anterior margin strongly convex; parapsidal line long; propodeal spine short; petiole, postpetiole and gaster as in major workers. COMPOSITION AND DISTRIBUTION OF THE SPECIES GROUP. Carebara pygmaeus (Emery, 1887) , C. rubra (Smith, 1860) , C. transversalis (Smith, 1860) , and C . panhai sp. n. are known from Sri Lanka , Laos , Thailand , Malaysia , Indonesia , and the Philippines .