My milkweed seems to be a magnet for aphids every year and yet I don’t worry too much since they seem to disappear later in the year. One of the reasons is that these aphids have Lacewings as predators. According to the video below Lacewing larvae can eat 200 to 300 aphids. It’s interesting that the Lacewing eggs are mainly where there are aphids and not on milkweed plants without aphids.
This picture comes from one of my plants, so you can see that these eggs alone could easily eat 2000 aphids.
Lacewings will eat also small caterpillars, but they certainly will have plenty aphids to eat before they find my caterpillars.
On my milkweed, if I find any Monarch eggs I usually put them in a cage to protect them.
All of the cabbage white caterpillars that I brought inside to raise ended up already being parasitized by the wasps in the picture. I estimate that each caterpillar was the host to 15 – 20 wasps. No wonder we don’t see more butterflies in the garden.
I brought some cabbage white larvae inside to show to a group and a couple of days later when I looked at them I saw all these cocoons in a bunch. I can’t quite figure out how they got there since I didn’t see them before. Right now I’ve got the cocoons in a sealed container to see what emerges – we’ll keep you posted. There’s also that little red blob near the top – I’m not sure what that is either. I’m guessing these are wasps. The larvae were inside one of my caterpillars and emerged in this form.
While it’s definitely a possibility that ladybugs might attack small butterfly larvae, in general they probably are much more beneficial than a problem. This year my Red Honeysuckle is infested with aphids and these ladybug eggs and larvae are certainly welcome to help control them.
If you’ve ever wondered why there aren’t 1000’s of butterflies flying around, here’s one of the reasons. Painted Ladies lay eggs on my Pearly Everlasting every year and even though they try to pull the leaves together and use silk to protect themselves, wasps seem to find a way in to get to them. Here’s a picture of a painted lady larva which has become the host for a wasp larva in the white cocoon. I’m keeping the cocoon in a sealed plastic tube to see what sort of wasp emerges.