Notes on intraspecific variation of some Gomphidae (Odonata) species in Cambodia (Oleg Kosterin)

Specimens of Burmagomphus asahinai Kosterin, Makbun and Dawwrueng, 2012 and Burmagomphus divaricatus Lieftinck, 1964 from SW and NE Cambodia show differences in the development of the light pattern. One male of the latter species has unusual posterior spinules on posterior hamuli. Two males of Orientogomphus minor (Laidlaw, 1931) from the same locality in NE Cambodia have substantial differences in the thoracic and abdominal pattern. NE Cambodian specimens of Gomphidia abbotti Williamson, 1907 and Lamelligomphus castor (Lieftinck, 1941) have minor differences from data on these species from literature. Caution is necessary when composing and using keys for identification of the mentioned genera of gomphids.