Abstract
Meranoplus Smith, 1853 is distributed in the Old World tropics, from Africa, Asia, New Guinea to Australia. There are four species Meranoplus bicolor (Guérin-Méneville, 1844), M. castaneus Smith, 1857, M. laeviventris Emery, 1889, and M. mucronatus Smith, 1857 previously recorded from Thailand. In the present paper, two new species of the genus, M. siamensis Yodprasit & Jaitrong, sp. nov. and M. tanomtongi Yodprasit & Jaitrong, sp. nov., are described based on the worker caste. Additionally, M. malaysianus Schödl, 1998 is recorded for the first time for Thailand. A key to the Oriental and Indo-Australian species, based on the worker caste, is provided. The new species and the new record were found to nest in soil.