St. John's-wort or Klamath weed is not native to North America. Until it was brought from Europe in colonial times, North American insects had never seen the plant. St. John's-wort quickly spread because it was poisonous and thus not eaten by most insects. The plant manufactures a poison called hypericin that is activated by light. This poison is powerful enough to kill even livestock that might be foolish enough to eat it.
But there are several types of insects that not only eat St. John's-wort, but thrive on it. Some beetles, larvae of moths and butterflies and leaf miners munch happily away on the plant. No, they're not immune to the poison. Instead, they have figured out how to prevent light from activating the poison. The leaf miners chew tunnels inside the leaves, staying out of direct sunlight. The moth and butterfly larvae use a similar approach. Some even tunnel inside the stem. A European beetle and its larvae also eat the plant. Adult European Beetles have a thick shell that shelters their bodies from the light. Their larvae eat St. John's-wort only at night, and then, before the sun comes up, they burrow into the ground.
If evolution were true, these insects would have had only a few centuries to identify how the poison works and evolve a counter to it. It clearly makes more scientific sense to conclude that God taught these creatures what they needed to know to eat St. John's-wort without harm.