23 Jun Bleaching Milkweed and Monarch eggs to Eliminate O.e.
O.e. is a microscopic parasite on milkweed and especially tropical milkweed that can, over a year or two, accumulate to where it seriously damages if not kills monarch caterpillars and butterflies.
To help eliminate it, some people bleach the milkweed in a 5% bleach solution and even harvested eggs.
Quoted from https://monarchjointventure.org/resources/faq/bleaching-milkweed-and-eggs (Follow link to read more)
I’ve heard of people bleaching their milkweed and monarch eggs while raising monarchs. Should I do this?
Dr. Sonia Altizer, director of Project Monarch Health based at the University of Georgia, contributed the answer to this question.
When raising monarchs to study parasite infection at the University of Georgia, we often bleach milkweed stalks that might have been contaminated with OE spores or other harmful microbes before feeding to monarchs. We especially do this when caterpillars in our lab die of unknown causes, or if we suspect that OE is present in wild monarchs in the area. Milkweed fed to captive monarchs can be bleached by soaking 15-20 min in ~5% Clorox solution (regular strength Clorox in tap water), followed by a thorough tap water rinse. Be sure to submerge stalks completely and gently agitate under water. Stalks can be partially air-dried or blotted with a clean towel.
I also want to mention the critical importance of bleaching habitats after raising a batch of caterpillars into chrysalids and emergence as monarch butterflies. Using 10% bleach and 90% water, soak for at least an hour to kill off bacteria, viruses and O.e. that can kill new batches of caterpillars. Watch video of how I bleached one of my smaller habitats
https ://youtu.be/zgNCP4cU84c 
