What do I do now?

[Newt]

I hope someone can help me. I am an avid gardener and have been gardening for many years. Last year I decided that I wanted to feed the monarchs so I planted milkweed and bronze fennel. I got several butterflies in the garden as I have many nectar plants, and in August I discovered 7 cats on my fennel! What a great surprise. I watched them everyday and noticed that the seven turned into just two left after a week. Well, I have discovered that one has formed a chrysalis and has done it on a plant in a pot that must come in for the winter.

Here's my problem. It's getting cold and I have to bring in the plant, but the chrysalis is still there. It was formed the week of August 11th and it doesn't look like it's going to emerge. I need to bring in the plant soon and I don't know if I should cut off the branch it's on and place it in the garden, and if so, where in the garden? Should it be above where the snow will be in the winter? I'm afraid that bringing it in the house will cause it to emerge and then what? I don't want it to die or freeze.

TIA,
Newt

[drader]

It is safe to say that your chrysalis (if it is indeed a monarch) is not going to hatch. They should emerge in about 14 days; the one in question has been around for 6 weeks. Otherwise, I would have suggested that you go ahead and take the plant inside. If healthy, the butterfly would have emerged within a few days and could have been released in plenty of time to make its journey to Mexico.

[Newt]

Hi Drader,
Thank you so much for responding. I thought I had read somewhere that it can take as long as 6 weeks for it to mature. I did notice tonight that there is a tiny hole on one side of it. Any idea what could have invaded?

Newt

[Jim]

Hi Newt - welcome to the forums!

Monarchs feed exclusively on milkweed - there are over 100 species so they come in all shapes, sizes and colors. We will be updating our Milkweed Photo Guide at

http://www.monarchwatch.org/milkweed/guide/

so stay tuned!

The caterpillars that you observed feeding on the fennel you planted were swallowtail caterpillars (which will also feed on dill, parsley, carrot, rue, etc.) and so the chrysalis that you found was also that of a swallowtail.



Swallowtails that pupate in August or September may emerge as late season adults or they may overwinter as a pupa (if kept cool or outdoors). After 6 weeks as a pupa I would normally say that it would emerge in the spring; however, that tiny hole that you spotted in the chrysalis indicates that this particular swallowtail pupa was parasitized by a tiny polyembryonic parasitoid wasp.

This is actually a fascinating life history in and of itself: an adult female wasp located your developing caterpillar and deposited a small number of eggs inside which subsequently divided to ultimately give rise to 100s (1,000s in some cases) of wasp larvae. The wasp larvae fed on the swallowtail caterpillar but still "allowed" it to pupate. The wasps finished their larval development and pupated themselves inside their host. A short time later (about the time you would expect the adult swallowtail to emerge, I believe) the adult wasps emerged within the chrysalis, chewed a small hole in the outer wall and exited en masse.

I think I've got some pictures around here somewhere - I'll look and post them ASAP.

[Newt]

Hi Jim,

Wow, great info. I went back and looked through the photos I took and you are so right! Unfortunately I only have them stored on my computer and can't post them here. I do indeed have a parasitized swallowtail cocoon. I thought I had read somewhere that the monarch chrysalis has gold on it, but I wondered if this might be some poor relation that didn't have any gold!

I don't ever use any pesticides or herbicides in the garden, and haven't for 16 years, so there's no telling which of the wasps it could be. I just let everyone balance themselves out. Guess it's time to get some field guides on butterflies and moths. We've had some beautiful visitors that I spend hours trying to id on the net. Great idea for stocking stuffers!

Thank you so very much for your help!
Newt

[Jim]

Unfortunately I only have them stored on my computer and can't post them here.

I'm working on a way for you to post your own images but in the meantime if you send the images to me via email I can post them online for you to use in forum messages if you'd like ... after all, a picture really is worth a thousand words

BTW - "cocoon" refers to the silk covering that most moths spin around themselves before pupating and "chrysalis" refers to the "exposed" pupa of most butterflies. There will always be exceptions to the rule, but in general this holds true. Here's a monarch pupa (chrysalis):

[Newt]

Thanks Jim,
It would be fun to be able to post photos here. I am constantly chasing butterflies around the garden. I must look quite a site.

If I have one to ID I will certainly take you up on your offer. Thank you so much!

Newt