problems with milkweed?

[Lori5]

I have reared monarchs for a number of years now and know that some just do not make it through all the stages. I have had trouble with a few lately that start to make the chrysalis and then died. I also tried to raise cats that I bought from monarch watch and they all died. Could there be something wrong with my milkweed? (It is in my fower bed.)

[Jim]

Monarch mortality in the wild runs pretty close to 99% - meaning that out of 100 eggs that are laid only 1 will make it to adulthood. There are all sorts of predators, parasites, and disease that can affect the larvae and of course if their milkweed is ever treated with chemicals that can have a negative impact on them as well.

Before I go too far down this road it would be helpful if you could provide a few more details about your particular critters - how/where they were reared, what they looked like when they died, what type of milkweed was used, etc. Photos are always a big help, but may not be an option in this case...

[Lori5]

The caterpillars looked like normal until the started to make the chrysalis. They formed the J and started to shead their outer skin and just didn't finish. They then turned black and I removed them from the container. The milkweed I feed them is growing in my flower bed but it is loosing leaves and some of them are turning a dark almost purple color. I try not to feed these to the caterpillars. All of the caterpillars have been laid on these plants and then when I find them I bring them inside to raise. My son and I have done this for a number of years but this is the first year I have had this problem. I have thirteen chrysalis right now and not had this problem for a while.

[drader]

not sure, but this sounds like the same problem I had with a few larva last year. Upon close inspection, I discovered a thin thread of dried mucus hanging from my dead larva (the larva were as you said hanging in the J shape from the top of their cage). On the floor of the cage, I found some brown pupae which I collected and hatched in a jar. Turns out that my wild captured larva were infected with some species of parasitic fly. Look for those pupae; you may have the same problem.

[Jim]

The parasitic fly drader is talking about is a Tachinid - I posted photos along with some links to more info at

http://www.monarchwatch.org/forums/viewtopic.php?t=108

For what it's worth, the rate of parasitism of wild larvae seems to be way down this year from last...I think Chip will have more to say about this in a future Update.

[butterflylover]

I too have had trouble with my catapillers dying this year. Last year I raised over 80 and only lost about 2. This year I found 77 catapillers and lost count on how many died. Same thing they mostly were either in the J form and just died or were heading there to hang and did not make it to the top of the container. Just hung and oozed dark green and black liquid from their body. Two died extremely little. And two made it to crylisses and then either fell or turned brown. I don't recall such a fatality rate as this season was. Are the containers I used contaminated now?
I also am curious about the plant. Can the leaves be decontaminated? And when the plants get different colors in there leaves are they not good for the catapillars any more? So many questions, so much to learn. Any advice?