Prodasineura yulan is described from a male from Maludam National Park, Betong Division, Sarawak, Malaysian Borneo. It is allied to Prodasineura interrupta.
The final instar larva of Acrogomphus jubilaris Lieftinck, 1964, is described and figured for the first time based on exuviae from four male and one female larvae collected in Sarawak, Malaysian Borneo. The adults of A. jubilaris are very rarely encountered. The larvae, however, are surprisingly common in forest streams in Borneo. It is compared with A. malayanus Laidlaw, 1925 and A. walshae Lieftinck, 1935, and notes on behavior, distribution and habitat are included. A map including all known records of A. jubilaris is provided.
Phaenandrogomphus safei is described from a male from the Kalabakan Forest Reserve, Sabah, Malaysian Borneo. It is the first species of Phaenandrogomphus to be recorded from Borneo. Onychogomphus treadawayi, known from Busuanga Island in the Palawan region of the Philippines, is transferred to Phaenandrogomphus.
Telosticta fugispinosa sp. nov. (holotype male, from Borneo, Sabah, West Coast division, Crocker Range National Park, Inobong, Kimamabang waterfall stream system, 21 ix 2012, deposited in RMNH) is described from Kinabalu National Park and Crocker Range National Park in Sabah, Malaysian Borneo. It is distinguished from all other species of Telosticta by the form of the male anal appendages.
The final instar larva of Orthetrum borneense Kimmins, 1936, is described and figured for the first time based on exuviae from three male and six female larvae collected in Sarawak, Borneo (East Malaysia). It is compared with an early instar larva, which was matched to the adult O. borneense by DNA barcoding, and the known larvae of other species of this genus that occur in the region.