Beetle & giant stinging tree interaction

The advent of canopy access by scientists  led to measurements of whole-tree herbivory in Australian rain forests, not just the understory within easy reach. This approach led to the discovery that tropical forest herbivory is much higher than previously assumed.

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One of the most incredible interactions was the Australian giant stinging tree, also called the gympie-gympie tree, and its host-specific beetle predator. The giant stinging tree, as its name implies, has thousands of stinging hairs that coat both leaves and stems. Its physical hairs can painfully tear the skin, and its chemical hairs inject a toxin into the freshly scratched surface. In 1908, a chemist named Petrie reported that stinging trees had a toxicity up to thirty-nine times stronger than that of common nettles. Ouch! Both giant stinging trees and common nettles are in the same plant family (Urticaceae), but nettles grow approximately three feet high in fields, whereas stinging trees grow to 200 feet in rain forests. One incredibly resilient beetle, appropriately named the giant stinging tree beetle, is adapted to not only crawl upon the scratchy leaf surfaces, but also consume the otherwise toxic foliage. The beetles consumed on average over 40% leaf surface area in the canopies of giant stinging trees, creating a characteristic lacy pattern in the forest canopy.

Learn more about Meg's research at canopymeg.com.

 

Research

by Meg Lowman, PhD,

Director of Global Initiatives and Senior Scientist in Plant Conservation, California Academy of Sciences