Bye-bye fly! – Four types of carnivorous plants

Bye-bye fly! – Four types of carnivorous plants – Venus’s flytrap, sundew, pitcher plant, and bladder wort

Deborah Churchman

What happens when a fly gets caught in a Venus’s flytrap? It’s so gross, you may not want to know.

Some wetland wonders are just plain weird–like plants that “eat” insects. Why do they do that? The soggy soil they live in doesn’t have enough nitrogen for the plants to grow strong. How can they get more nitrogen? First they attract tiny creatures like this fly (see photo, left). Then . . . GOTCHA!


This grasshopper sandwich (right) started when a hopper crawled inside one of the flytrap’s leaves. Big mistake. The hopper touched a couple of the tiny trigger hairs sticking up from the leaf’s surface. Swoosh! The leaf’s toothy spines locked together, t rapping the hopper.

Now the plant is oozing out special juices. Ooey gooey–the juices will turn the hopper’s insides to liquid, which the leaf soaks up. (The liquid has the nitrogen that the plant needs.) Later the leaf will reopen, and the hopper’s body shell will be carri ed off by wind or rain.


See these pretty flowers sparkling in the sun? They even smell good–just like honey. And here comes a fly to try them out!

Uh-oh–that fly should keep on flying. These aren’t flowers. They’re leaves with lots of stalks growing on them. At the end of each stalk is a sugary, sticky drop.

Oops–the fly didn’t keep flying (photo 1). Now it’s stuck! The plant’s gooey glue holds the insect fast. And the more the insect wiggles, the more stalks it touches. That “tells” the stalks to slowly, s-l-o-w-l-y curl around the fly, holding it tight (2) .

For the next week or two, the sundew will digest the insect. Then the stalks will straighten, the leaf will uncurl, and the fly’s body shell will wash away in the next rain.

In the spring, sundews have real flowers–not just tricky, sticky leaves. But flowers need insects to spread their pollen around. How do sundews keep pollen spreaders from being trapped? Each flower grows high on a tall, tall stem. That keeps the pollen-c arrying insects away from the tricky traps below.


Say you’re a beetle flying about. Hey–you spot a pitcher plant. The leaf sticking straight up smells like honey. And its bright lines (right) show you just where to land. So here you come. . . .

Look out! The leaf’s downward-pointing hairs make it hard to hang on. You start to slip, and the hairs keep you from crawling back up. Ker-splash! You fall into the pool (left). Can’t get out? You lose.

And the plant wins. The pool is mostly full of rainwater. But it also contains special juices and bacteria. These slowly turn an insect’s soft parts into goo. Finally the body sinks to the pool’s bottom. Plant hairs hold it there while the plant finishes digesting.

But not every insect that lands in a pitcher-plant pool is fooled. For example, some kinds of mosquitoes raise young there. The juices and bacteria don’t harm those tough guys.


This plant may have beauties blooming above the water (bottom, photo 1). But it has hungry beasts lurking below! On the underwater leaves and stems are tiny bladders (sacs). These bladders (2) are really tricky traps for mosquito larvas, water fleas, and other tiny creatures.

If a creature touches trigger hairs in front of a bladder’s “door”–whoooosh! The door opens and both water and the creature are sucked in. Whap!–the door shuts incredibly fast–in as little time as 1/500 of a second! And the creature is trapped. (One b ladder in photo 2 has caught a mosquito larva. But the larva is too big to fit!)

After catching its dinner, the bladder acts like a stomach and digests it. Yum!

Wetland plants sure can be weird. The things they’ll do to get that nitrogen!

COPYRIGHT 1996 National Wildlife Federation

COPYRIGHT 2004 Gale Group