Failure for Monarch to go from J to crysalis

[MonarchMom]

Hello. I have raised several healthy Monarchs this summer. I've tried to keep the cages clean, and with fresh food. Lately, I've had a couple of cats that went into the J position that evening, were still in the J position the next morning, and by noon they were hanging straight with a white string hanging down. Eventually they turned dark.

Is this how they normally act with a virus? Earlier, I had some crysalises start turning dark and had a string hanging down. I found little fly larvae pellets in the cage. So, I feel rather sure that they were parasitized by a small fly. But I am confused by the string hanging on the cat unable to go from the J position to the crysalis stage. Do they use the string to help keep them in the J position, but was released when they died? Did a parasite fly off of the string? Or does this sound like a typical virus?

Do I hope for the best with the rest? Move them to a fresh cleaned cage? Or were they probably already parasitized or virused when I brought them in? Can the female spread the virus with her eggs? They were quite small cats when I brought them in.

Any suggestions would be appreciated. Thanks.

[butterflylover]

Hello Monarch mom, your message caught my attention as I too had these types of problems with my cats this summer and crysalids. First of all kill those nasty little larva that come out asap! Secondly isn't this Monarch watch Forums just the greatest? I have learned a whole lot just since I have joined last week. I never realized why my cats died in the past. But since I've found this sight I now know so much more.

This problem you are having is a Tachinid fly larva. You can find more about it at the monarch watch site under parasites. The silky string coming from the cat or crysalid is the silk that they have lowered themselves to the ground with. I have a book here that I purchased from Monarchwatch. You might check into this also. Milkweed, Monarchs and More is the books name.
I also found on the website that you should sterilize your containers if you have had this type of parasite. You find all the answer at the website. I don't believe you will lose all of your cats to this as I had most of my cats in one container and I only lost 8 or so out of 77 cats. I hope you find my reply helpful. But Check out the site it really helps. Butterflylover

[MonarchMom]

Thanks so much Butterflylover for your suggestions. Sometimes it is so frustating. You try to do the very best that you can: bring them inside, keep their food fresh, keep their cage clean, and a lousy tiny fly still makes it in. I saw the blasted fly pellet catapalt out yesterday a.m. on my way to work.

I had had this problem with the crysalis, but wasn't for sure that it would happen with cats. Someone mentioned that it could happen to eggs, also.

I will check out the sites that you recommended. I have the book, "Milkweed, Monarchs, and More." It has been very helpful. Who would have thought that there are so many bugs, and parasites attracted to MW?

Congratulations upon your raising 77 cats. That is amazing! This is my first year, and I raised, tagged, and released 40. I now have 12 more 3-5th instar cats, that I hope to release before the weather gets bad. I've had the time of my life this summer. And a wonderful show of Monarchs migrating thru.

We are very fortunate to have these great forums.

What kinds of MW do you raise your cats on? I had better luck with swamp mw not wilting as bad as the tropical. But the yellow aphids really love it also.

Thanks, again for your help.
Monarch Mom

[butterflylover]

I raise all of my cats on the common Milkweed. I didn't even know there were different types of milkweed in Ohio until I found the forums. It has answered all my questions and some. I am so excited about this site and about being able to look for more cats next year. I just can't wait! I just hope I will be able to find the different plants around here.
Our season is done here, we have had several frosts and the common Milkweed were turning yellow and brown back in September. There is a great crop of common right around my moms house in her flower beds and that is where I find most of my eggs and cats. Maybe I will post some pictures of them next summer if I figure out how to do that. I do have trouble with those darn aphids also and a lot of ants and wasps. I grab those eggs off the plant as soon as I find them. I have learned that if I leave them to fend for themselves that they dissappear. So I get them as soon as I find them. Good Luck with the rest of your cats. butterflylover

[Keith Petrosky]

The same thing happened when I collected eastern tent caterpillars. I collected about 40, and 28 of them had maggots in them. They hatched during the night, and made cocoons. In a few days, there were flys all over. I felt bad for the caterpillars, because they were eaten inside, and died when the maggots emerged.

[Megathymus ursus]

Your larvae are parasitized by tachinid fly maggots. The maggots chew through the dead larva's skin and that gooey string is a silk thread they make to lower themselves to the ground. You must completely destroy the monarch larva and any maggots and pupae that have come out.

Where I live in So Cal, I would estimate the parasitism rate to be about 25-30%, at least from the season where I reared a whole bunch (2002).