When You’re an Ant, Even Plants Can Be Monsters
Monster Monday
October 12, 2015
Our inaugural Monster Monday features not an animal, but a plant. Can a plant be a monster? It sure can, if you’re an insect.
Some types of plants are carnivorous, meaning they need to “eat” meat to survive. Because they cannot chase down their meals, they have developed clever methods of trapping their prey.
The pitcher plant is actually a group of carnivorous green plants with pitcher-shaped leaves that form traps, usually trapping insects. Like other green plants, pitcher plants make their own food by a process called photosynthesis. However, pitcher plants live in places where they get little nitrogen from the soil. The captured insects provide nitrogen for the plants.
Pitcher plants come in an amazing variety of shapes and sizes, but they all have modified leaves that form a long tube, or pitcher. Insects are lured to the plants by bright colors or sweet-smelling juices. The walls of the pitcher are often slippery, causing an insect to slide to the bottom. Some types of pitcher plants have methods to prevent their prey from escaping, such as lids or bristles. After an insect slides to the bottom of the plant, it slowly drowns in the water pooled at the base of the pitcher. As its body dissolves, the plant absorb its nutrients.
Scientists have recently discovered another clever way that one type of pitcher plant uses outside forces to catch bugs. Ulrike Baur and colleagues at the University of Bristol in the United Kingdom recently reported these findings in the journal PNAS. The plant Nepenthes gracilis has a stiffened lid over its pitcher. Raindrops falling on top of the lid cause it to vibrate rapidly, helping to flick ants on the underside of the lid into its pitcher. This underside is just slippery enough to aid in flicking unsuspecting ants to their doom, but not so slippery that it keeps the ants from venturing out onto it in the first place. What looks to an ant to be a safe haven in a storm leads them to a watery grave.