Larvae and adults of Vietnamese species of Drepanocentron and Hydromanicus (Trichoptera: Xiphocentronidae, Hydropsychidae)

Genetic sequencing (with mtCOI) was used to associate larvae with two new Vietnamese caddisfly (Trichoptera) species from Bach Ma National Park, Hydromanicus calyx n. sp. (Hydropsychidae) and Drepanocentron dentatum n. sp. (Xiphocentronidae). Adult Drepanocentron dentatum n. sp. is distinguishable by the toothy dorsal margin of the male inferior appendages; the most similar species, D. vercaius, has teeth on the ventral, but not the dorsal margins of the inferior appendages. The larva of D. dentatum is fully described herein, the first larva to be described in the genus Drepanocentron; it can be separated from the other two known xiphocentronid larvae (Xiphocentron messapus and Cnodocentron yavapai) by the smooth, thin mesal margin of each mandible. Adult Hydromanicus calyx n. sp. is distinguishable by the cupped apices of the male harpagones; this character is absent in morphologically similar species (H. nieuwenhuisi, H. abiud, and H. serubabel). The larva of H. calyx is morphologically most similar to that of H. inferior, but can be distinguished by the presence of faint muscle scars interrupting the lateral margins of the stridulatory areas on the venter of the head.