I have been working on freshwater macroinvertebrates since 2019. I have collected the specimen from north west Himalayan region. I am not able to identify the caddisfly (TRICOPTERA).
Try the following literature, I'm sure they would be of help, especially Wallace et al. (1990) and Edington and Hildrew (1995).
Macan, T. T. (1959). A guide to freshwater invertebrate animals. London: Longman.
Croft, P. S. (1986). A key to the major groups of British freshwater invertebrates. Field Studies, 6, 531–579.
Wallace, I. D., Wallace, B., Philipson, G. N. (1990). A key to the casebearing caddis larvae of Britain and Ireland. Cumbria, UK: Freshwater Biological Association.
Edington, J. M., Hildrew, A. G. (1995). Caseless caddis larvae of the British Isles a key with ecological notes. Cumbria, UK: Freshwater Biological Association.
Pawley, S. (2011). Guide to British freshwater macroinvertebrates for biotic assessment. Cumbria, UK: Freshwater Biological Association.