Abstract:
Caddisfly larvae have been used in many fields. However, reported information on the rearing of caddisfly larvae in the laboratory was poorly understood. Therefore, it would be beneficial to study biodiversity of Trichoptera larvae in Phayao province. Samples of the larvae were collected from October 2019 to July 2020 in small streams at Wiang Lo Wildlife Sanctuary (Huai Mae Chun) and Phu Sang National Park (Nam Pueai, Nam Pueai upper stream, Huai Pong Pha, Huai Sai Kad, Nam Yuan upper stream, Nam Yuan Huai Pum) Phayao province (7 stations). A total of 2,795 individual caddisfly larvae belonging to 13 families were found. The larvae of the family Hydropsychidae were the most abundant from all stations. 7 families of case-making caddisflies, 5 families of net-spinning, and 1 family of free-living were found. The diversity index, richness index, and the evenness index of the larvae were highest at Huai Pong Pha (1.90, 3.50 and 0.86, respectively) and lowest at Nam Yuan upper stream (0.93, 2.27 and 0.48 respectively). Marilia sumatrana larvae of the Odontoceridae family were selected for study some optimal culture conditions in the laboratory. This study was divided into 3 experimental 1) The effects of the flowing and still water rearing systems on the growth and survival rate of M. sumatrana in the laboratory. The results indicated that the lengths gain of larvae cases reared in the flow water and still water were not significantly different (p > 0.05) and the survival rates of the flow water treatment were significantly (p < 0.05) higher than that of the still water treatment. 2) The effect of foods on the growth and survival rate of M. sumatrana in the laboratory. The results showed that the lengths gain of the larvae cases from treatments fed by catfish fry feed and shrimp feed were significantly (p < 0 .05) higher than those fed by leaf litter but the survival rates of any treatment were not significantly different (p > 0.05). 3) The effect of temperature (25, 30 and room temp.) on the growth and survival rate of M. sumatrana in the laboratory. The results showed that in all three treatments, there was no difference in the length gain and the survival rates (p > 0.05). In conclusion, the culture conditions of the M. sumatrana larvae in the laboratory should be reared in flowing water in 25ºC and fed with catfish fry feed. Finally, the results of this study might be applied to other types of caddisfly larval culture design.