Does milkweed yellows phytoplasma harm caterpillars?

Phytoplasmas are bacteria and are species specific. This means that they would not be able to live inside the caterpillars. These phytoplasmic organisms on milkweed are not known to harm caterpillars. They cause disease in plants and are spread by insects that feed on the phloem of plants, like leafhoppers. For more information on milkweed yellows phytoplasma, visit the Monarch Lab webpage: (https://monarchlab.org/?/resources-links/blog/milkweed-yellows-phytoplasma)