Hmm, that’s really interesting. I had the same problem with some of mine in November, but I thought it was either because I let them eat too much cucumber, or because perhaps the plants that seemed to mess up their chrysalis-making last year still had something wrong with them (I still have no idea what was going on there.) Maybe there’s something entirely different going on.
In all, I had 19 caterpillars, raised indoors, of which only 8 got to fly away in the end. Three just faded away as caterpillars, two chrysalides were just too shoddy, and three chrysalides coloured just as you described, but didn’t eclose without intervention, and the butterflies inside were too weak to inflate their wings or really to do much at all. I euthanised those.
The other three were all also too weak to fly, but lively enough that I kept them around and fed them. Two lasted a month or so, but Maxilla will be 10 weeks tomorrow. That’s a bit old for a butterfly this time of year, no? I’m kinda wondering if she has a malformation that has made her body behave like the non-sexually-active overwintering ones. I may post about it after she finally keels over, because she seems like she’d be an interesting case if there was a Lepidopteran Dr House.
I have had the same thing happening with chrysalides I have bought inside to protect them from predators. I suspect I have not had enough ventilation around them or possibly too much sun – the chrysalides are turning too black. I lightly spray them to mimic the dew daily. The lids of the chrysalides do not look healthy.
Please keep us informed. Caryl (Wellington)
Thank you Jacqui. I do have other castles, so will open up a new one for the next batch. I am hatching them from eggs on leaves (on the damp paper towels and lids with holes in,,within the castle) and the caterpillars seem to do fine. I did steralise the castles at the end of last season, but will do it again once this one is emptied. Just seems odd that this batch (apart from 2 or 3) seem to all end up not hatching out properly. You get to know the length of time that the butterfly takes to hatch out,once the chrysalis colours up and the butterfly is visible inside. I did wait until day 3 for this lot, but now wonder if I should have helped them a bit earlier, maybe then they might have hatched out stronger.This pattern of not hatching,does lead me to believe it maybe a virus or similar.Many thanks for your reply..
PoplarPark it could be a number of reasons. There are not only predators and parasites to contend with, which are at least visible, but also pathogens that are impossible to see.
If your caterpillar castle is now empty I suggest washing and sterilising it and starting again.
Remember that not every caterpillar will become a butterfly. It is Nature’s way of keeping everything in balance. It sounds like you are doing everything right. It can be frustrating at times like this!
Jacqui
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