The early investigations of Russian Far East Trichoptera is connected with A.V. Martynov (1879-1938) who is recognized as a “Father of Russian Trichopterists”. About hundred species described by Martynov were reported from Russian Far East (RFE). Then, I.M. Levanidova (1914-2005) devoted her life to study caddisflies of Pacific Russia and demonstrated the high biodiversity of Trichoptera fauna for the region. If the list of Russian Trichoptera includes 641 species in 148 genera of 28 families of caddisflies (Ivanov, 2010), the Far East of Russia consists of 435 species of caddis belonging to 103 genera of 26 families, it is about 67,8% of Trichoptera fauna of all Russia (Table). Nevertheless, specialists estimate that the real quantity of species should be much more as the majority of the territory still isn't investigated rather well. The core of RFE Trichoptera fauna the is represented by species of Palaearhearctic subregion of Palaearctic Region and species distributed in Eastern Palaearctic. Transpalaearctic and Holartic species are presented in much less number. Connection of North Pacific Russia with North America through the ancient Bering Bridge is traced based on caddisfly fauna. The fauna of Kamchatka is comparatively poor in comparison with continental. The fauna of Sakhalin and the Kuril Islands reflects, on the one hand, communication with eastern Asian continent, with another ? connection with the territory of the Japanese Archipelago and coastal territories of South-East Asia. Taxonomic difficulties of East Russia Trichoptera fauna studying is planning to resolve owing to complex investigation of morphology, distribution, genetic characteristics of caddisflies in cooperation with the international teams of trichopterists of USA and countries of East and North East Asia. Taxonomic list of the families and genera of Trichoptera in Russian Far East (Pacific Russia and Yakutia)

The caddisfly is an aquatic insects that resembles small moth. Silk is produced by the larvae through a pair of labial silk glands. The larvae, caddisworms, use silk not only to produce ‘capture nets’ to collect food particles from the water environment but also to construct ‘silken cases’ for their shelters in running water. Physically, two different processes of silk-producing systems are reported among the different species of arthropod animals: terrestrial and aquatic silk productions. Although both types of silks can be produced along its sophisticated process through a sequential pathway from silk gland, most of our recent knowledges of silk producing system are dependent on those revealed from the terrestrial animals including silkworms or spiders. Therefore, this experiment was initiated to reveal the fine structural aspects of the silk producing system of larval stage of the caddisfly Hydatophylax nigrovittatusu with light and electron microscopes