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Kelly Blair, Anna Fogt, Scott Graf, and Lauren Leipprandt
Aquatic Ecology class, BIO 390, Biology Department, DePauw University
Spring semester 2010

Caddisflies are an insect in the order Trichoptera.  The adults are small moth-like insects with two pairs of membranous wings.  The larvae are aquatic.  The presence of caddisflies larvae in a stream or river is a good indicator of water quality.  Past studies have shown that areas with rapid current velocity, high flow rate, and shallow water depth provide higher quality habitat for caddisfly larvae.  

We conducted surveys of caddisfly larval cases in riffles and pools in Big Walnut Creek in November 2009.

We observed higher numbers of larval cases in riffles with higher flow rates.  Caddisfly larvae prefer flowing water over pools.  

Total number of caddisfly cases observed in riffles and pools and stream flow rate (meters per second) in Big Walnut Creek, Nov. 3 through Nov. 17.  

Location Number of
caddisfly cases
Flow rate
Riffle 1 7 0.38
Riffle 2 8 0.67
Riffle 3 8 0.32
Riffle 4 12 0.87
Pool 0 0.21