How does the butterfly get its spots?

All we found were sawfly larvae.
This summer, my daughter and I have gone on several “bug-hunting expeditions”. These expeditions always begin with the same elaborate routine: donning the explorer vest, collecting the magnifying glass, bug house and butterfly net, and consulting the “bug map”. The goal is to find a caterpillar that we can capture, feed and watch as it morphs into a butterfly. So far the only thing remotely resembling a caterpillar we have found is sawfly larvae.

My daughter is fascinated by butterflies. We have at least three books on her bookshelf about butterfly life cycles, and just the other week, a trip to the library yielded yet another butterfly book for bedtime reading. Butterflies are fascinating creatures. Not just for the four-year-old who wonders in awe at their amazing life cycle, but for the biologist who marvels at the development of the intricate pattern of their wing eyespots. Wing patterns in butterflies are amazingly varied among species and between different wing surfaces (forewing and hindwing) of the same individual. How are these patterns determined? Continue reading “How does the butterfly get its spots?”