New species of caddisflies (Trichoptera, Ecnomidae, Polycentropodidae, Psychomyiidae) from Mekong tributaries, Laos.

Four new species of caddisflies are added to the fauna of Mekong River, Laos. Described and illustrated are and (Ecnomidae), (Polycentropodidae), and (Psychomyiidae) from tributaries of the Mekong River, Laos. can be distinguished by the characters of the superior appendages, which are slender and club-shaped in lateral view. In , the inferior appendages are tubular with a concave incision subapically and truncated apex. has the distal process of the dorsal branch of the inferior appendage close to the base of the inferior appendages and the length of the process is half of inferior appendages. can be distinguished by the structure of the dorsal branches of the harpagones and apical sclerite. The outer branches of the harpago in the latter species are bifurcated and bent 90° degrees outward, and the inner dorsal branches of harpago are curved outward. The apical sclerite is indiscernible.