Earlier this week, the sixth graders bid a fond farewell to the monarch butterfly they raised from a caterpillar.
Ms. Merow, BL’s director of academic technology and middle school technology coordinator, brought in two caterpillars along with some milkweed leaves back in September. Only seven days old, the caterpillars took up residence in the sixth grade science room with middle school science teacher Mrs. Brown, where students could watch their progress from the larval stage (caterpillar) to pupa (chrysalis) and, finally, to adulthood (butterfly).
The students marveled at how much the caterpillars ate as they grew. Monarchs only eat milkweed. The toxins in the plant make the caterpillars – and eventually, the butterflies – poisonous, so most predators will not eat them! After nine days, the first caterpillar went to the top of its enclosure and formed a chrysalis, which is where the transformation to butterfly takes place.
Sadly, the class discovered that the first caterpillar had been infected with a parasite. Another insect had laid its egg inside the caterpillar. Once it had formed a chrysalis, the egg inside hatched and the larva, which looked a lot like a maggot, came out of the chrysalis. The class removed the damaged chrysalis and destroyed it in case there were other eggs inside!
A few days later, the second caterpillar made its way to the top of the enclosure and formed its chrysalis. This one was healthy and included the distinctive gold band and dot decorations on the green background. Eleven more days passed before the adult butterfly emerged from the chrysalis. (The butterfly must have been shy as it happened over the weekend when no one was at school to see it!)
The class fed the butterfly sugar water since it would normally drink nectar from the flowers it visits in the wild. On Wednesday, the sixth graders took the butterfly outside to release it. Because this is the last generation of the summer, Mrs. Brown expects the butterfly to make its way to overwintering grounds in Mexico. The last group of monarchs each summer make this long journey south to hibernate in Mexico. In the spring, they begin the journey north, but it takes three generations to make it as far north as Maryland.
The sixth grade science team hopes to raise more monarchs next year, and may even tag them. To learn more about monarchs and participating in tagging, visit monarchwatch.org.