What did we learn this year?
Multiple mayfly emergences were documented in the news this summer:
observers reported light emergence (100 to 500 individuals) of
(mayfly) on July 22nd in lock and dam pool 5 near Wabasha, MN, and a slight emergence (less than 100 individuals) of
(giant mayfly) on July 26th in pool 8 near La Crosse, WI.
The phenology calendar below shows when observers reported a "yes" observation for mayflies (colored bars) or a "no" observation (gray bars) along the Upper Mississippi River this year.