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Caddisflies in Big Walnut Creek

Students:  Kelly Blair, Anna Fogt, Scott Graf, and Lauren Leipprandt

Introduction:  Caddisflies are an order, Trichoptera, of insects.  They are small moth-like insects with two pairs of membranous wings.  Larvae are aquatic.  The presence of caddisflies in a stream or river is a good indicator of water quality.  Past studies have shown areas with rapid current velocity and shallow water depth provide higher quality habitat for caddisfly larvae.  Higher flow rate translates into more caddisfly larvae.


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.  Caddisfly larvae prefer flowing water over pools.

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