monarch caterpillars survival when removed from milkweed

Asked June 18, 2019, 2:49 PM EDT

Please respond about this post appearing today on nextdoor.com. If this is not a good practice for survival of monarch caterpillars, please inform the public. Monarch Caterpillars Hello, Our son is obsessed with caterpillars...thanks, and we have a friend that gave us two monarch caterpillars from his land to raise into butterflies. The problem is, our yard only has one milkweed plant and it is not big enough for the two caterpillars. Does anyone have any extra milkweed they are growing or can share/spare? I know you can find it at the parks, but I don't want to pick plants at the park, and those leaves might have eggs on them already too. Any help would be appreciated. Thanks!

Dakota County Minnesota milkweed horticulture monarch caterpillars

1 Response

Thank you for the interesting and thought provoking question. While it seems logical to assume that collecting and rearing monarch eggs in captivity through release of the adult butterfly would help the struggling monarch population, there can be problems with this if practiced on a large scale. According to Monarch Joint Venture, a partnership of federal and state agencies, non-governmental organizations, businesses and academic programs, working together to protect the monarch migration across the United States, "potential risks include releasing monarchs that are adapted to captive conditions, increasing parasites and disease in wild monarch populations, and making it more difficult to understand natural monarch distributions. Recommended strategies that do support monarch populations in the long-term include creating or improving habitat, minimizing monarch and habitat exposure to pesticides, and participating in citizen science or other research".
That being said, your son's desire to raise 2 caterpillars is not a problem. You will have to find a source of milkweed for the insects somewhere. Maybe you can find some through your nextdoor.com contacts. If you can't find any, probably the best thing to do is give them back to the person who gifted them, or ask him for some plants. He may know what the eggs look like so that the plants he gives you won't exacerbate the problem.
The Monarch Lab at the University of Minnesota may be able to help shed light on this subject as well. Contact information:
Read about rearing monarchs: https://www.monarchwatch.org/rear/index.htm
Thank you for contacting Extension.