Elevated carbon dioxide conditions pose threat for the Monarch butterfly

Milkweed plants from the chambers were fed to hundreds of monarch caterpillars this summer. Milkweed is a monarch caterpillar’s only food, satisfying its nutritional needs while providing an invaluable medicinal boost. The plant’s leaves contain a bitter toxin that helps the insects ward off predators and parasites. But previous work at U-M’s northern Michigan biological…