Raising monarch caterpillars. The milkweed plant that I harvested the cats...
Raising monarch caterpillars. The milkweed plant that I harvested the cats was pretty infested with yellow aphids. Our first butterfly emerged yesterday, however her wings did not fully open and I am pretty sure she will die. We have about 12 more cats. My question is, will the fact the eggs were laid on the aphids affect all the butterfly that will emerge?
Delaware County Ohio monarch butterflies
Oleander aphids are very common on milkweed plants. While they are unsightly and can be distressing to see, they are not considered harmful to milkweed plants or monarch caterpillars. Typically an assortment of natural enemies (lady bird beetles, lacewings, parasitoid wasps) will also be on hand to consume the aphids.
Here's more information on the aphids
and about the aphids and monarch caterpillars, from Monarch Joint Venture: