The larva of the endangered Heterophaea barbata (Martin, 1902), from Luzon Island, the Philippines (Odonata: Euphaeidae)

The final instar larva of the large, spectacular Philippine and Luzon endemic euphaeid damselfly Heterophaea barbata (Martin, 1902) is described and illustrated for the first time, based on field collected exuviae of both sexes. Identification is by supposition, but larvae of the only other euphaeid on the island, Euphaea refulgens Hagen in Selys 1853, have been previously described and illustrated and can be confidently ruled out. The specimens are exceptionally large for the family and present several novel structural features not recorded in other euphaeid genera. The antennae of the principal specimen studied were asymmetric in length and numbers of segments, suggestive of a possible teratological event caused by genetic load or environmental factors during development. This and other specimens exhibited up to 14 antennomeres, more than hitherto recorded for any odonate larvae.