Key to Continental Southeast Asian Calyptomyrmex

This worker key is based on: Jaitrong, W., Yamane, S. 2018. A new species of the ant genus Calyptomyrmex Emery, 1887 (Hymenoptera: Formicidae: Myrmicinae) from Laos and new records of C. rectopilosus from Thailand and Hong Kong. Natural History Bulletin of the Siam Society 62: 131-139.

Three species of Calyptomyrmex are now known from Continental Southeast Asia and can be divided into two groups: 1) species that have spatulate hairs (narrow basally and expanded distally, with a rounded tip) and lack propodeal teeth (C. beccarii Emery, 1887), and 2) species that have fine hairs (with the same width throughout entire length) and have propodeal teeth (Calyptomyrmex laotius and Calyptomyrmex rectopilosus).

1

Hairs on head and mesosoma spatulate (narrow basally and expanded distally, with a rounded tip); propodeal teeth absent . . . . . Calyptomyrmex beccarii

Hairs on head and mesosoma fine (same width through entire length), simple and blunt at apex; propodeal teeth present . . . . . 2

2

return to couplet #1

Head and mesonotum with only fine deep punctures or macropunctures; head width 0.76—0.79 mm; promesonotal hairs often = 2 times as long as those on head; promesonotum with 12-14 hairs . . . . . Calyptomyrmex laotius

Head and mesonotum with macropunctures and bearing several longitudinal rugae; head width 0.56—0.66 mm; promesonotal hairs almost as long as those on head; promesonotum with more than 20 hairs . . . . . Calyptomyrmex rectopilosus