We are fortunate enough to have several small patches of milkweed on our property. For the last couple years I have been perfecting the art of caterpillar catching. This year I started with about 50 eggs, and they are all hatching!
So how do I do it?
First of all, this project is S-I-M-P-L-E as long as you have access to milkweed. For those who aren't sure if they have some, it looks like this... Most plants are about 3-4 feet tall, however I do have some that are 1-2 feet. They can blossom clusters of pink/white flowers that have a floral fragrance (however my blooms are wilting) then they grow a cluster of pods that are green, bumpy, and cone like. If you still are not sure break off a leaf or tear it. It will ooze a white milk like liquid.
The eggs can be found mid July in Minnesota. They usually are on the underside of the leaves. They are often oval shaped and white or yellowish. Usually there is one to two eggs on a leaf. When I find one I put it in a container with a damp paper towel. It can take up to a week to hatch. A lot of times if I find one egg on a plant, other leaves will also have some. Also look for hatched caterpillars. They are TINY when first hatched, but will quickly grow to 1 1/2 inches and yellow/black striped.
This year I actually witnessed many of the caterpillars hatching from their eggs. I started watching when I noticed the eggs to have a dark tip. Soon the tinest black head, white body climbed out of each one. They often eat their egg shell and then start nibbling on the leaf. Daily I would replace the leaf and keep it in a container (let some fresh air in).
After a few days the little buggers will show significant growth. If you feel they are ready for their "home" you need to put them in a container that has a nice "roof" for them to eventually attach themselves to to make a chrysalis. You can buy or make it. I found that Tinker Toys make a good structure, and pantyhose make great walls. Just slip it over and close the panty hose on the side with a binder clip. They will stay in here until they turn to butterflies (just over a week to turn to a chrysalis and an additional week to a butterfly).
They will eat a ton when they get large. You must add leaves daily. You may clean out the cage as long as the caterpillars haven't attached themselves to the cage. When they are ready to turn to a chrysalis they go to the top of the cage. They attach themselves with a silk thread and hang in a J shape. In the next 24 hours they will turn to a chrysalis. This year I was fortunate to witness the transformation. It was just luck that I saw it due to the process takes about 2 minutes from start to finish. AND IT WAS AMAZING!!!! If you notice the caterpillar in the J shape to look greenish and making undulating movements, keep a close eye on it and you might be in luck!
In a week the chrysalis will get dark, within 24 hours you will have your butterfly. After it "hatches" let it dry for a while. The dyes on the wings need to dry before they can fly. We let ours go immediately after. If you want you can keep to observe for a while by placing flowers that butterflies get nectar from or by cover a small continer with sugar water, poke a medium size hole in the cover and push through a rolled up paper towel. The sugar water will wick up the paper towel for the butterfly to eat. If you do this observe the tongue (proboscis) it is like a straw, it curls up when not in use, but long when drinking. Also, fun fact... butterflies taste with their feet.
If you get the abundance of eggs like we did this year, share the joy with friends and family with children.