Diversity of Adult Caddisfly (Trichoptera) in Two Intermittent Streams During Dry Season in Phayao Province, Thailand

The effect of anthropogenic activities on natural intermittent stream and diversity of adult caddisfly were studied at the University of Phayao, Thailand. The caddisfly adults were collected monthly from 2 intermittent streams (the Huai Thub Chang and Huai Luang streams) from February to May 2015 (cool-dry to hot-dry season) using a black-light trap. Huai Thub Chang stream received wastewater from the oxidation pond, while Huai Luang stream was affected by an agricultural field of the university. Both streams are located in a deciduous forest. The 14 species of 7 families were collected and identified. Cheumatopsyche lucida (Hydropsychidae) and Leptocerus dirghachuka (Leptoceridae) were found in both streams. C. lucida was the most abundant species. Micrasema turbo, Amphipsyche meridiana, C. globosa, Diplectrona lavinia, Macrostemum dohrni, Marilia sumatrana, and Wormaldia relicta were found only in Huai Thub Chang stream, whereas C. dhanikari, Lepidostoma doligung and Chimarra toga were found only in Huai Luang stream. A high number of C. lucida in both streams from February to April reflected a drought effect on the emergence of the caddisflies. Huai Thub Chang stream had a higher diversity of Trichoptera species than Huai Luang stream because of the variety of substrate types which were suited for the larval stage, especially hydropsychids.