Hi - first of all let me say that I have been a monarch butterfly enthusiast for years and have been on the Monarch Watch email list and have visited this site for a long time now! Thanks to all of the people at Monarch Watch for the wonderful work they do!
Now, on to the reason for this post... this summer I got back into rearing a couple of monarchs for my mom who is teaching a summer school class. I have raised several groups of monarchs. The first group of eggs I had this summer developed into beautiful, healthy-looking butterflies. The second group of eggs, however, has been a nightmare.
I first realised there was a problem when one of the five monarchs from this second group 'J'd for over a day and then died. Hoping that it was just a problem with that larva, I got rid of it. The next chrysalis turned dark brown and the butterfly never emerged so I got rid of that, too. The final three chrysalises have developed brown spots over the past few days, but my mom wanted to show the chrysalises to her students so she took them to school this morning anyways. Well, one of the three butterflies with the brown-spotted chrysalis emerged this morning. I didn't see it, but my mom told me it had this very disgusting mutation. Apparently, the butterfly itself looked normal and was happily flapping around its bucket. However, when she picked it up to take it outside to release it with her students, it had a regular-sized caterpillar actually attached TO the body of the butterfly. She said it was as if the creature had two bodies: it had the fully formed adult butterfly body; butterfly legs, head, and all, and somehow attached to it was a caterpillar - with a moving and squirming caterpillar head and legs. Needless to say, she said it was horrifying and disgusting. Unfortunately, she didn't have our digital camera with her at the school so couldn't take a picture of it. She said it couldn't fly away and she ended up leaving it on the lawn. We have 2 other chrysalises that have yet to hatch and they have brown spots - I'm assuming to avoid a repeat of this incident, we should destroy those?
Finally, a few days ago (before I discovered that my monarchs were all diseased) I found 2 young, new caterpillars and although I have been feeding them fresh milkweed and they have had no contact with the diseased larvae, I am wondering if they are still in danger of having this strange disease because I have put them in the same container as the diseased ones had lived in?
also, all of the diseased caterpillars were roughly the same age as each other so I have a feeling they all came from the same adult female butterfly.
I know this story is slightly bizarre, but I'm curious as to whether anyone else has had this experience. Thanks!