After a six-hour ride over increasingly treacherous roads, it took a full day's hike up almost 3,000 feet for Leonora Bittleston to reach Nepenthes Camp in the Maliau Basin, an elevated conservation area in Malaysian Borneo with a rich, isolated rainforest ecosystem.
After waiting three years for collecting permits, Bittleston, then a graduate student at Harvard University, entered the basin in search of one thing: pitcher plants. These carnivorous plants have evolved traps to lure, drown and digest animal prey to supplement nutrient-poor soils.
Bittleston needed samples of the liquid inside the pitchers to compare to pitcher plants from much closer to home in Massachusetts and along the Gulf Coast. Though unrelated, both plant families had converged on similar adaptations for trapping prey, and Bittleston wanted to know if the communities of microbes and small animals housed in each liquid-filled pitcher were as similar as the traps themselves.
In new research published Aug. 28 in the journal eLife, Bittleston, University of Wisconsin-Madison botany and bacteriology professor Anne Pringle, and others, reveal that the communities created inside pitcher plants converge just as the shape and function of the plants themselves do. Despite being separated by continents and oceans, pitchers tend to house living communities more similar to one another than they are to their surrounding environments.
Asian pitchers transplanted to Massachusetts bogs can even mimic the natives so well that the pitcher plant mosquito-a specialized insect that evolved to complete its life cycle exclusively in North American pitchers-lays eggs in the impostors.
The Weird World Inside A Pitcher Plant
The New York Times: A species of pitcher plant found in Singapore isn't very
good at dissolving the prey it catches, but it gets nutritional
help from worm larvae that live and eat within its maws.
On the soggy floor of one of the only remaining intact forests on the island nation of Singapore, the egg-sized heads of carnivorous creatures emerge from decaying leaves. They appear to be belching, or singing, or screaming out the catch phrase of their cousin in Hollywood - "Feed me Seymour."
This is Nepenthes ampullaria, an unusual pitcher plant found on the islands of Southeast Asia and the Malay Peninsula. And its "Seymour" is the worm larva of Xenoplatyura beaveri, a species of fungus gnat that develops inside the plant's mouth. When grown, it looks like a mosquito with big biceps.
They've got a strange relationship, these two.
The plant gives the gnat baby a safe place to eat and develop. In exchange, the baby builds a web across the plant's lips, captures and eats other insects and then defecates into its maw, or pitcher. The plant eats the ammonium-rich droppings. And all is well in this miniature world of weird.
It's not romantic. It's not sweet. But researchers call this relationship "mutualistic" in a study published Wednesday in Biology Letters. Their findings, based on laboratory experiments that simulated this insect-plant interaction in the wild, suggest that cohabitation may have its benefits for these two obscure organisms. How tiny pitcher plant communities like this one and others the group is studying function may reveal secrets of plant and insect life, said Weng Ngai Lam, a graduate student in botany at the National University of Singapore, who led the research.