June 15, 2012
This Plant Uses Raindrops To Catapult Food
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We´re all quite familiar with carnivorous plants. Plants such as the venus flytrap feed on flies and other insects, providing an appetizing place for bugs to feed before snatching them up in their jaws and feeding on the remains. Now, scientists from Cambridge University have found that a similarly carnivorous plant employs the laws of physics to help it find its meals.
Hailing from south-east Asia, “Pitcher Plants” (or Nepenthes gracilis to those in the know) are able to use drops of water and gravity as a food delivery system.
These pitcher plants look just as they sound: A large pitcher-like vessel with a single leaf just over the opening, hang from vines. Inside these pitchers is a dangerous liquid which dissolves the bodies of the insects. The ridges of these pitcher plants are large and slippery, but in case the ants and other insects are sure of foot, the plant has one more mode of attack: That single leaf.
The underside of the leaf is coated in an attractive-yet-waxy sweet nectar which draws in ants and other insects. Once there, the plant need only wait for a drop of rain to fall on the top side of the leaf. The force of the rain drop is enough to catapult the bug into the pitcher, never to escape.
This feeding behavior has only recently been noticed by scientists at the Cambridge University.
Dr. Ulrike Bauer from the University of Cambridge´s Department of Plant Sciences led the study. “It all started with the observation of a beetle seeking shelter under a Nepenthes gracilis lid during a tropical rainstorm,” she said in a prepared statement.
“Instead of finding a safe – and dry – place to rest, the beetle ended up in the pitcher fluid, captured by the plant.”
Dr. Bauer noted they had seen bugs crawl on the underside of the leaves before without falling in, so they began to look at the plant more closely.
“So we assumed that the rain played a role, maybe causing the lid to vibrate and ℠catapulting´ the beetle into the trap, similar to the springboard at a swimming pool.”
To test their theory, Dr. Bauer and team decided to simulate rain drops with a hospital drip and recorded the effect these drops had on the plant and its victims. They recorded the number of ants who came to feed while they were dripping water and ants who fed during the dry times. According to their study, ants who visited during the dry times–when they weren´t operating the drips– were able to come and go unscathed. When the “rain” came, on the other hand, nearly 40% of all ants who came to visit ended up at the bottom of the plants belly.
These plants have been well known to scientists as a carnivorous plant for hundreds of years. It wasn´t until Dr. Bauer conducted field research in Borneo last June that it was discovered exactly how these plants feed on other insects.
“It is amazing to see things like this in the field. The pitcher plants have very unique mechanisms but this is perhaps the most amazing,” said Dr. Bauer to the Daily Mail.
“The fact that we keep discovering new trapping mechanisms in the 21st century makes me curious what other surprises these amazing plants might still have in store.”