Sunday, March 21, 2010
Future biologists often enjoy raising caterpillars at home or in class, and watching them turn first into chrysalides and then to butterflies. The hands-on experience of feeding, tending and observing butterflies throughout the life cycle can spark a love of learning. Furthermore, kids get a frame of reference when they visit Pacific Science Center’s Tropical Butterfly House.
Be aware, there are complications raising butterflies! We hope that those of you who wish to try raising butterflies yourself can learn from the many calls we get. We want you to have the best chance possible to bring caterpillars safely to adulthood.
To begin - the most common problem is timing. People may receive butterfly kits as a gift during times of year when rearing them is problematic. We recommend against starting raising caterpillars in the late summer, fall or winter. An entire life cycle can take as little as six or eight weeks, so you could end up with butterflies that can’t be safely released outside.
Pacific Science Center is always available to take in butterflies in this situation. Give us a call or e-mail first, so that we know you are coming. But a little planning can help you avoid the problem altogether.
If you find a caterpillar in the fall, it is best to leave it where it is. Left outside, the chrysalis will naturally adapt itself to changing temperatures and can survive even freezing weather. It can use temperature and day length to assess the time of year, and will not emerge until the season is ready. Inside, the temperatures may shock it into developing too quickly and emerging while it is still wintery outside.
Classrooms must plan not only around the seasons but around weekends and breaks. Pupae must be monitored daily, and planning ahead for weekends will help prevent the sorrow of coming in to a bunch of butterflies that emerged but had nothing to eat.
Not all butterflies emerge in good condition from their pupae. In an average batch of ten or twelve, you might have a few butterflies with crumpled wings, butterflies that die shortly after emerging, or even some pupae that do not mature into butterflies at all.
For some, this is a learning moment; for others it can be upsetting and sad. If you work with kids, plan for how you will approach the idea of death and physical damage. Be ready for some strong feelings and open discussion.
For most people, it makes sense to release native butterflies into the outdoors, and bring purchased ones to Pacific Science Center for flight in our exhibit. But once they have raised butterflies, some people choose to keep them in confinement, providing artificial nectar in the form of sugar water. The original kit for the caterpillars may have come with a small amount of food which will be gone. At some point, butterflies may breed and produce eggs. If you wish to carry on the life cycle, know what your butterfly species eats, and have that food available immediately! If you do it in advance, researching and finding plants is fun. Not so when hungry mouths are waiting.
Caterpillars and butterflies do not represent the same time commitment, either in years or in hours per day, as a dog or a cat. But they are completely dependant on us while we care for them. Still, we can become very attached and caught up in the outcome. Please take the time early in the process to plan ahead for the entire life cycle. It will maximize the educational value and cut down on the stress.
Sarah Moore, Life Sciences Manager