Do wasps lay eggs in monarch butterflies?

Yes, some species of wasps, particularly certain parasitic wasps, can lay their eggs in Monarch Butterflies. These wasps may inject their eggs into the caterpillars or pupae of monarchs, and the developing larvae feed on the host. This parasitism can negatively impact the butterfly population, although it is not a widespread issue. Monarchs have evolved some defenses against such parasitic attacks, but they are not entirely immune.