The question is, do butterflies who lay eggs on medicinal plants have more surviving children who do the same, or is there something else that causes butterflies to lay their eggs on medicinal plants?
(PhysOrg.com) — Monarch butterflies appear to use medicinal plants to treat their offspring for disease, research by biologists at Emory University shows. Their findings were published online Oct. 6 in the journal Ecology Letters.
“We have shown that some species of milkweed, the larva’s food plants, can reduce parasite infection in the monarchs,” says Jaap de Roode, the evolutionary biologist who led the study. “And we have also found that infected female butterflies prefer to lay their eggs on plants that will make their offspring less sick, suggesting that monarchs have evolved the ability to medicate their offspring.”
“The results are also exciting because the behavior is trans-generational,” says Thierry Lefevre, a post-doctoral fellow in de Roode’s lab. “While the mother is expressing the behavior, only her offspring benefit. That finding is surprising for monarch butterflies.”