Caddisfly Life History 
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FALL WINTER SPRING 
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Fig. 4. Seasonal variation of case length in P. postica larvae. Horizontal lines = 
means; vertical lines = ranges; open rectangles = one standard deviation; shaded 
rectangles = standard error of the mean; letter = month; and number = sample 
size. 
ACKNOWLEDGMENTS. — We would like to express our thanks to 
Miss Vickie Crager for typing the manuscript. Also, we thank the follow- 
ing gradutate students for assisting in the field work: Kerry Bledsoe, Bill 
Cremeans, Pam Dolin, Paul Hill, Steve Lawton and Joan Schramm. 
