The Picture of the Day from Science 360News Service today, March 22, is about the Asian tamarisk leaf beetle. The picture, as all the Science 360News Pictures of the Day, is lovely. Beautiful colors, succinct description.
The beetle (Diorhabda carinulata and Diorhabda sublineata), a natural pest of the tamarisk tree, is being introduced in the western U.S. as a biological warfare agent against the tamarisk tree--a species of tree introduced to the U.S. 100 years ago.
Makes sense. In its native habitats (China, Mongolia, Russia, Tunisia, Egypt, and other parts of Asia, Africa, and Europe), the beetle keeps the tamarisk under control. And the tamarisk tree here in the U.S. needs to be controlled, even erradicated. The tamarisk is destroying native plants and ecosystems in the U.S. west. It displaces riparian woodlands, compromises habitat for wildlife, increases erosion and contributes to demise of water quality.It's also a highly flammable tree; so it increases wildfire activity. The tamarisk tree is bad news for the ecology of the western U.S.
But is introducing a beetle that, while a natural pest of the tamarisk tree, really a good solution? The beetle is also non-native to the very ecological system experts are trying to protect and restore. I'm not a biologist. I'm not a forester. I'm not a trained scientist of any kind. But I wonder, "So, once the tamarisk trees are destroyed, what native plants (or animals) will the beetle evolve to eat?" Sure, it may not be for another hundred years. But what new problems will we have introduced?
I'd like to think that the experts have wrestled with this question.
With my MSP2 hat on, I wonder if this would be a good question with which to prompt students to wrestle. Where and when have we introduced other non-native species? Why were those choices made? What have been the results? How do we make decisions about when the risk is worth the introduction? And can we extend the conversation outside of biology? What about ideas? Cultures? Attitudes?