So this is the third year I have had milkweed planted in my garden. The first two years I started with common milkweed, this year I replaced it with swamp milkweed. Throughout that time I have watched monarchs lay many eggs on all the milkweed. I have seen little caterpillars, but not once have I seen any of them make it to a fully grown caterpillar. This year the caterpillars have gotten to about one week old at the most, and continue to disappear. Recently I was in the garden and saw a nymph stink bug on the swamp milkweed near the leaf where a young caterpillar was resting. I thought nothing of it since I didn’t know what kind of bug it was at the time. Then when I returned to the area half an hour later I
thought I’d have another look and the nymph had its mouth attached to the caterpillar. It was too late to do anything, I brushed it off the leaf but it maintained its hold and it scurried off on the ground with the caterpillar in its mouth. That was the first time I ever saw a bug eating the caterpillars. However each time I inspect the milkweed I don’t see many bugs on the leaves themselves (just ants sometimes and various bees/wasps visiting the flowers for nectar but I never see those on the leaves), it was actually a rare occurrence that I saw the stink bug in action. I’m not out there 100% of the time so I can’t be sure but I think other bugs are eating the caterpillars.
So basically the only way for any monarch to survive is for me to take the leaf inside and protect it inside an enclosure I built. This has been rather disappointing because it kind of defeats the purpose of planting milkweed in the garden in the first place. Instead of providing a habitat for monarch to live, I’ve provided a food source for insects/animals that eat monarch.
Ultimately it would be nice for the monarchs to live out their life cycle outdoors. The first year when I didn’t have too much time to take care of them I grew them indoors for as long as I could and then placed them back onto the milkweed when they were big enough - do you think this helps increase their chances?
Does anyone have any recommendations regarding this?
I haven’t found any ways to reduce stink bug populations without killing everything else–they destroy my tomatoes and peppers. Mother nature works this way though, so I suggest just letting things happen and appreciate the cycle of life. What we don’t know is whether our unnatural plantings create environments that are actually detrimental to monarchs because they concentrate predators also.
Edited since other people have pointed out that hand-rearing monarchs creates artificial selection / removes natural selection
So the best thing you can do to help is plant more milkweed in different areas, so that more monarchs are attracted, and so that the predatory species are more dispersed. Try planting multiple types of milkweed that are native to your area.
If common and swamp milkweed are both native to where you live, I would highly suggest replanting more common milkweed, and any other native species you can find. Some species like common milkweed more than swamp milkweed, and vice versa, so variety would definitely be beneficial.
If you have neighbors / are friends with your neighbors, you could try offering them some milkweed plants or seeds and encouring them to grow it too, so that there’s more habitat overall. Try to share them with friends or family too.
If there are wild areas near where you live that milkweed would be able to grow on, you can try to help spread seeds there too. This can also be accomplished as easily as leaving a few seed pods on the plants over winter to let the seeds disperse naturally. When I was up in Pennsylvania still, I’d take a stick with some seed pods on it and wave it in the air up on the porch to get the seeds to be picked up by the wind and carried further, lol, and always made sure to throw some in areas further away where I’d already seen milkweed growing, to help the genetic diversity.
And you will just need to accept that it’s the natural way of things. You haven’t defeated the purpose of planting the milkweed - milkweed benefits many species, not just monarchs, and it doesn’t belong to them or exist solely to benefit them. Even if it’s disappointing to see the monarchs get eaten, it’s still benefiting the ecosystem because those predators have their role to play, and you are providing habitat not only for the monarchs, but predators and pollinators. Anything that eats a monarch caterpillar or visits a milkweed plant is part of the ecosystem too, and they have just as might right to be there as the monarchs.
Predation and disease are very important ways that natural selection works to ensure a healthy, robust Monarch population. When we try to “save” caterpillars, no matter how well intended, there is no getting around the fact that we are deliberately circumventing natural selection and ensuring that unfit genes spread in the general population. The best advice is one repeated from other posts here – plant a lot of milkweed. Your six scrawny milkweed plants in the middle of your garden (speaking metaphorically here) make your Monarch caterpillars sitting ducks for predators and parasites. It’s like putting a goldfish pond under a heron rookery.
I have the same issue with heavy predation in my yard - which is entirely Edge Habitat as it is surrounded by yards with lawns. Edge habitats are heavily predated and there can be few survivors - which is a problem with periodical cicadas in what is now fractured territories.
My solution is to position a large tomato cage over Monarch or Swallowtail caterpillars with a giant net laundry bag over it and a very short open edge at the bottom in case one heads off to pupate before I notice it is time.
When they are at the pupation stage, I remove the laundry bag portion and since that is a short period, I hope they are successful. I don’t look too hard for the pupae, but assume most survive and are within my native plants.
I’d recommend planting more milkweed and trying to make a few really dense stands of it where they can hide better.
Depending on where you life, it may not even be legal to attempt to interfere in other ways - I believe California just banned captive raising of monarchs because it was introducing too many weak and sickly individuals into the breeding pool.
I have mixed feeling about it, yes I’d rather see a strong self sufficient species in the end, but at the same time they were just classified as endangered and are 3 steps away from extinction because of human intervention. I’d rather help a few survive because that’s all I can do. Unfortunately, most other solutions need to happen at levels well beyond my own means.
I’ll try implementing the suggestions above, like placing the milkweed in different areas of the garden. It’s true that now it is all clustered in one area. And because of that the flowers attract all the pollinators. I have other flowers for pollinators in the garden but for some reason everything is very attracted to the swamp milkweed flowers when they are in bloom.
Of course, they would need to be on board with the monarch project, since some people consider milkweed a weed. There are several species of Danaus, including the monarch, in the Dominican Republic, and two native milkweed species: tropical milkweed Asclepias curassavica and Caribbean milkweed Asclepias nivea. However, farmers in the area disapprove of milkweed because they consider it deadly poisonous to cattle; planting milkweed for monarchs would not win me points with the community.