Raising monarchs inside
Why do this? For one thing, of course, it's fascinating!
For another, though, it's a way to optimize the number of eggs that actually turn into a butterfly. I've read estimates that only 5-10% of the eggs laid survive to butterflyhood. Parasitism, predation, weather, even milkweed latex all take their toll. The first year I did this (2006) I started in late August and raised 29 out of the 35 eggs and caterpillars I collected. This year (2007) I started early and by the end of the season will have raised and released more than 200. I didn't keep a good tally of what I collected so I don't know my success rate, but it's pretty high.
Here are some photos.
Here's one of the four 10-gallon aquariums I had. After seeing the first few caterpillars pupating underneath the very edge of the aquarium, and also under the little triangle of cardboard on the screen, I realized they were looking for cover, so I put some cork hotpads on the top. It worked since they started attaching themselves underneath the pads away from the edge. Next time, I'll probably just put cardboard there, though, since their silk attached the pad to the top of the screen, so I wasn't able to take them off until they left. TIP: Have one extra aquarium without a lid. After pupae attach to the underside of the top, the only place you can put it down is on another aquarium. You'll need to do this frequently as you add new caterpillars, new milkweed etc. Usually I used the extra aquarium for very tiny caterpillars that wouldn't be traveling very far.
Here's one of my four aquariums filled with monarchs in various stages. They went through a LOT of milkweed, so if you're planning to raise them inside, make sure you have a large supply available. You need more than would be necessary outside since first, more of the eggs laid will survive, and second, the milkweed doesn't last as it would outside attached to the plant - just like any cut flower.
Don't worry when you see the newly-emerged butterfly dripping what looks a little like blood. Just as human babies expel meconium after birth, so do monarchs. They continue to "drip" for a while, but the fluid becomes clear. This shows the drippings from a few monarchs in one of my aquariums.
They don't all survive. Perhaps these two had a parasite.
If you look closely, you'll see a black dot on the back of this caterpillar. I think it must be some sort of parasite. Anyway, it seemed to bother the caterpillar, so I knocked it off gently with the end of a pencil and it seemed to work - in other words, I kept this caterpillar separated to see what happened, and it became a butterfly. Would that have happened if I left the black thing there? I'll never know...
The monarch in all its glory - before its wings get tattered (although this one has a small tear in its wing). If this monarch was a member of the last generation of the summer here in Central New York, it will be making the long journey to Mexico to overwinter with all the other monarchs east of the Mississippi, to reproduce the first generation in the South next spring. If it was a member of an earlier generation, it will mate and produce another generation here, living only a month or so.
This one probably won't make it to Mexico no matter what generation it's in, but even so, it seemed to manage quite well around the yard. I bet the bird that took that chunk out of its wing has learned not to do so again!
