Why are caterpillars dropping off my milkweed plants?

Question

I recently transferred 3 milkweed plants from pots to ground. After about a week I noticed 5 caterpillars had dropped off the plants and onto the ground below. Some were small. What would cause them to drop off too early? There may have been some fertilizer in the soil I mixed in when I transferred them. Would this cause them to drop off? The plants are healthy and monarchs have been laying.

Answer 1

This may be an issue with natural selection. Many insects, including caterpillars will be in a number so great that they could not possibly all survive. If they are all dying, and there are none left on the plant, then it would be a concern, but as long as some survive, then I would suspect this to be a natural occurrence.