Disinfecting leaves with BLEACH before feeding caterpillars?
Chip Taylor of Monarch watch recently wrote in a forum: "Bleach is a no-no for many reasons. There are many other ways to eliminate spores from leaf surfaces. Oxine (chlorine dioxide) is a better oxidizing agent and is much safer. But, there are other methods as well. It would be helpful if someone would conduct a systematic assessment of various ways to eliminate O.e. spores and other pathogens from leaf surfaces."
We only rinse leaves with water and never have issues with sick monarchs. If we did have an ongoing issue I would try disinfecting milkweed with hydrogen peroxide before bleach. I would try a mixture similar to what's suggested for sick and fungusy plants:
Info on bleaching eggs and or milkweed in regions with high prevalence of OE
Water has worked well to rinse cuttings in our northern region, but there may be other options more monarch-safe than bleach for killing more pathogens...we will update this if we learn of other monarch-safe milkweed disinfection options