Nature Canada

New fact unveiled about Monarch

Can a sick Monarch medicate itself or its young one to ward off infection? That was the questions Jaap de Roode, Assistant Professor at Emory University, was trying to answer. With the aid of a $500,000 grant from the National Science Foundation, Jaap de Roode delved his researched into the wild to explore the relationship between the protozoan parasite, and the monarch.

Photo by Nancy Balharrie

The protozoan parasite (Ophryocystis elektroscirrha) invades the caterpillar gut and persists right into the monarch’ adulthood, the now adult monarch subsequently passes the infection onto its young ones (larvae). It is a known fact that caterpillars ingest toxins to which they are immune but that in turn make them toxic to others warding off predators. Jaap de Roode and his team have now established that the monarch not only uses cardenolides, chemical found in milkweed, to ward off predators, but to fight the infection too.

Jaap de Roode was quoted in Discovery News saying,

“We have shown that some species of milkweed, the larva’s food plants, can reduce parasite infection in the monarchs. 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. We believe that our experiments provide the best evidence to date that animals use medication.”

 

Jaap de Roode, discusses his latest findings in this video.

The monarch’s sel-medicating behaviour is trans-generational, meaning that while the mother is expressing the behaviour, only her offspring benefits.

Caterpillars have no preference over a less or more toxic type of milkweed, only the adult monarch, more specifically only the infected adult monarch.

New discoveries such as this one help pave the way for potentially beneficial breakthroughs for human and non-human species. And it’s a timely reminder that we can learn so much from species, common and rare, which makes conserving such biodiversity so important.

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