Chlorogomphidae

The Chlorogomphidae is a small family comprising three widely recognized genera: Chlorogomphus (47 species), Chloropetalia (4 species), and Watanabeopetalia (4 species). Chlorogomphids are large and spectacular dragonflies confined largely to the mountainous regions of tropical Asia. Nymphs can be found at stream edges, at pools, or at the bases of waterfalls where they burrow into the sand, mud, or gravel. In Thailand, eight species of Chlorogomphus and only one species of Watanabeopetalia have been recorded. Nymphs of both genera are very similar, although they can be distinguished by characteristics of the ligula, protibia, and relative lengths of the caudal appendages. They share features such as large size, body setose and tapering caudally, labial palps strongly developed, legs relatively short, caudal appendages very sharply pointed, and coloration light-yellow to yellow-brown. The distribution of Watanabeopetalia in Thailand is restricted to only one northern province, whereas Chlorogomphus is more widely distributed across the country.