Night — day drift patterns and the size of larvae of two aquatic insects

✍ Scribed by William D. Skinner

• Book ID: 104613914
• Publisher: Springer
• Year: 1985
• Tongue: English
• Weight: 184 KB
• Volume: 124
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00015246

✦ Synopsis

A test of Allan's (1978) hypothesis about differential drift abundance of mayflies of the genus Baetis between night and day, and the size of larvae was performed at a mountain stream in Idaho. Palisades Creek, Idaho, contains a different species of mayfly, B. tricaudatus, and vertebrate predator, Salmo clarki, than Cement Creek, Colorado (B. bicaudatus, and brook trout, Salvelinus fontinalis). Consequently it was not known if B. tricaudatus would exhibit a similar pattern as its congener in Cement Creek, with large instars tending to avoid daylight drift, as found by Allan (1978). However, similar results were observed in the present study. It appears that the earlier hypothesis may have generality for geographically distinct streams with a different vertebrate predator and mayfly prey. The existence of a similar pattern for chironomid larvae was also tested, however, no such pattern existed. This discrepency between taxa may be due to differential predation, or to inherent differences in drift abilities.