Follow up:

I just went out to look around and gathered up no less than SIX seemingly quickly dieing cats, two of a size to go into chrysalis and he others not small by any means. WHAT IS GOING ON!?!? I managed to find ONE healthy cat, and he is on a potted milkweed a bit apart from the garden. Seriously, can no one here help me?

Predation by wasps is a frustratingly common occurrence. The only way I know to protect the caterpillars and chrysalises is to bring them inside, or into a protected enclosure. That would mean feeding them by hand or growing milkweed in pots that you could move in and out of the enclosure as it gets eaten. It does add to the work of raising Monarchs, but it improves their survival rate dramatically.

If you are finding cats dying even without being attacked by predators, there may be disease involved. Can you take pictures of what you are seeing?

Martha

Cavalier, I had that happen to my first J of the season as it was in mid pupation early this summer. I saw the chrysalis dripping clear green fluid, and saw the wasp that attacked it. It's a terrible feeling to see our cats sick or dead! Sorry you're having them die. If you could posts pictures it might help.

After mine died from the wasp, I built a 3' wide by 4' long by 4' tall enclosure over some outdoor in the ground milkweed plants. I used metal stakes that I already had, and bought aluminum screening for the 4 sides and top. I put the posts inside the screening, that was a mistake. The cats liked making their J on the hot metal posts, so I had to keep shade cloth over them. Next year I'll re-build it with the posts on the outside. It was easy to make.

The enclosure has worked out really well by keeping out lizards, milkweed bugs, wasps, flies, black mold, powdery mildew, maybe OE, and insects that eat and curl the leaves. Just those clever dark yellow milkweed aphids got in.

I have plenty of other milkweed growing outside the enclosure. In the early season I would gather the cats and put them in the enclosure to grow and form chrysalises. Later in the season a few got sick so now I have to raise them indoors. The milkweed I get outside for my indoor cats is much healthier if it's from the enclosure, but I wash it well anyway. The MW from the enclosure has no tiny monarch hatchlings on it and has almost no insect damage, black mold damage and likely no OE since no butterflies can visit it..

The MW not enclosed, but in the same yard, has a huge amount of black mold and insect damage on it. Probably 3/4 of the milkweed not enclosed isn't usable as food due to insect damage and mostly black mold damage. Same yard, I'm not sure how the aluminum screening keeps mold out, but it does.

This late in the season your cats could be dying from OE, a deadly parasitic spore. (or from other things). The southeast has more OE than the west coast, and OE was a big problem for me last fall and winter, and still is this year but less so. You might google 'OE' to see how to spot it in cats and chrysalises, and google 'Monarch diseases'. There are a few good sites with pics. I haven't seen wasps around in a few months here (so. Ca.)

Only 2 out of 100 Monarch eggs survive in the wild. You had a great amount of successes though! Indoor raising is a lot of work and very time consuming.

The other thing is to look around for wasp nests and spray them with this can you can get from a hardware store that allows you to stand more than six feet away and hit the nest. The worst in my yard are the paper wasps. They make nests in the pipevines. Normally I can find most nests and eliminate them.

I don't work with any cats but I just wanted to say I'm very sorry to hear of something so terrible happening to all of your hard work. I'm glad the experts were able to sympathize and also offer advice. Good luck to you.

Sorry to hear you're running into so many problems, but it sounds like your garden is young and going thru its "waspy " stage. As your host plants mature and multiply, you'll have more cats than wasps.
You can also plant your host plants among other greenery to give your cats a place to hide during the day.
Raising cats in the house is still the best way to increase Monarch numbers.
John

Sorry to hear what happened to your cats, Caviler. During my first few weeks of raising monarchs I noticed that the "bulbul" birds likes to eat them, and they are the constant snacks for "anole" lizards here in Hawaii...so I placed the bigger cats on a sturdy, jackson's camelion's cage we found in a swapmeet..from then on I raised and released 300+ butterflies with no problems. I also used old screened laundry baskets from walmart.

I am curious, how come there is a predation on monarch cats despite the fact that they are filled with milkweed poison?? They are also colorful, another signal of being poisonous.

Invertebrates (insects) have no problem with the toxins. Some birds don't have a problem either. Monarchs are eaten during their migration and in Mexico.

Here is a link that might be useful: Monarchs are eaten by birds