As we enter the warmest time of the summer, the threat for swimmer’s itch will arise. There are many websites that show the swimmer’s itch parasite’s life cycle and it effects, so I won’t cover that part of it. The simplest story is that it comes from snails, and that is the part we can help.
Being a lake mollusk, we can control the snail with the molluscicide copper sulfate (on sale now through July 9th). You can either apply it now as a preventative, or wait until reports of swimmers itch around the lake start to emerge.
To treat for swimmer’s itch, apply copper sulfate at the maximum label rate of 5.3 lbs/acre/ft. The time of day doesn’t matter, but the wind speed does. Apply this or any other pesticide with little to no wind for the best potential outcome. It can take 2 days for the parasite to be killed off in the treated area. There is no guarantee that this will work, unfortunately. A 2nd treatment will likely be needed.