Thrive with five!
In the past, we've provided 10 eggs to most classes. A few teachers have preferred fewer, saying that five are less work.
The switch to five was made to ensure we have enough eggs for everyone. It's always a little uncertain whether our laying females will cooperate. And they don't lay at all when the weather is cold or rainy.
Efficiency!
Working with only 5 eggs per class, it's very important you use the best methods, so most of your eggs make it to the butterfly stage, and especially, that your students actually see the butterfly emerge. Many teachers have a high % of success (number of healthy butterflies divided by number of eggs received).
But don't feel bad if you lose one or maybe two of the five eggs. Expect about 80% or more success (losing only one caterpillar in five). Here's a quick review of how to avoid losses.
Common causes for loss of eggs/small caterpillars...
- Knocked off the stem, especially during transport. Careful! Place the jar in your car's cupholder.
- Tiny cats are dropped, go missing, during transfer to fresh milkweed. Keep a clean, well-lit work area with a white surface when transferring. Remember, they attach by silk to your brush.
- Spiders eat small eggs or cats at night. Inspect fresh milkweed for spiders. Cover bins at night. Place your stem and jar in a saucer with water, to act as a moat.
- Food dries out and leaves curl up. Eggs and caterpillars become hidden, or they may wander away. Very time-consuming to unroll leaves. Transfer before leaves dry out.
- Monarchs dry out or overheat. At all stages, mist several times a day. Never place them in direct sunlight for more than a short time.
- Neglect over the weekend, especially when hatching, leading to bad food, dehydration, or wandering.
- Caterpillars overlooked and left behind when given fresh food. Keep old food for two days in a bin; missed caterpillars will climb to the top.
- Cannibalism! The more eggs on a leaf, the more likely the caterpillars first out will eat nearby eggs. You could lose 20%. So, it's best to transfer caterpillars soon after they emerge, or to cut out eggs on a square of leaf and place each one in the compartment of a white ice cube tray.
Causes for loss of larger caterpillars, chrysalids, or adults
- Left behind in old food. See above.
- Disease. If you follow our general recommendations, disease should not be a problem. Especially, remember not to place caterpillars in any container that held adults, without sterilizing it first.
- Caterpillars wander off to form the chrysalis. Surprise! Butterfly appears from nowhere! This can lead to squished monarchs. Normally, caterpillars absolutely do not wander if they have good food. But once they have been in the 5th instar for a while, as large as a whole finger, they wander away to form the chrysalid. Keep a sharp eye for the first wanderer, then place a lid on the bin.
- Accidents that cause injury. I advocate letting kids handle large caterpillars and even adults (3 hrs or more after eclosure). They are very robust. That said, accidents are possibly my greatest cause of mortality. Especially chrysalids--which are very fragile and will break if dropped more than a foot or so. If you carefully prepare chrysalids for eclosure, you can avoid accidents or deformed wings.
- Butterflies wings get deformed during eclosure. Allow emerging butterflies ample room to twist during expansion of wings. If they fall down, tape paper towels to a slippery surface, so they can climb up. If you see one fall down, offer it a paper towel to cling to, then tape the towel and butterfly to a place where it can hang.
- Butterflies escape after eclosure, leading to injuries. They will not fly for at least 2-3 hours after eclosure, so leave them in the open where kids can see them. They give warning before they fly, gradually fluttering more and more. Move them to a mesh cube.
Counting helps success
At each transition, such as when providing fresh food, count the caterpillars and place a label with the number and date where you can see it. Then you know how many to look for next time you make a transfer.
Keep a record elsewhere of the numbers and dates and try to account for any losses. This is how you improve. In life, we count anything important.
Control the time butterflies emerge
The solution is simple. Keep the chrysalid in the dark--in a closet or with a black plastic garbage bag over it, until students are ready. The butterfly will emerge within half an hour of seeing bright light.
The photo shows the morning of emergence. The afternoon before, the colors will be just barely visible.