His argument is this: The insects that are the basic food source for many birds and many beasts — skunks, opossums, foxes, raccoons, even black bears — have evolved over many millennia to feed on the native plants that make up the pre-human landscape. In turn, the plants have evolved to limit that damage. Certain caterpillars feed only on oak leaves, others only on black cherry. The caterpillars that become monarch butterflies eat only milkweed leaves. “We have a problem with our native plants; we call them weeds,” Tallamy said. “If we could call milkweed ‘Monarch’s Delight,’ that would be great.”
Tallamy and his researchers have done simple experiments, such as planting a white oak in a 12-foot by 12-foot square of open ground, then counting the caterpillars on it once it grows. One count came up with 19 species and 410 caterpillars all told.
