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Sundews: The Best Carnivorous Plant for Catching Fruit Flies

September 22nd, 2009 · 7 Comments ·

My husband Tom (who normally blogs at Bikejuju) continues our carnivorous plant adventures:

Lyanda recently described our semi-tongue-in-cheek experiments with using a Venus fly trap to catch fruit flies. As at least one commenter rightly pointed out, however, sundews (plants in the Drosera family) are much more suited to the task, covered as they are with rows of sticky little fly-attracting mucilage droplets.

Sundew_wide_480

This weekend Claire and I were headed past Seattle’s Indoor Sun Shoppe, where they are mad for carnivorous plants, so we stopped in to pick up a sundew for some additional experimentation. While we were there Claire also bought a pitcher plant, completing our sample collection of the triumvirate of classic carnivorous plants: Venus fly trap, sundew, and pitcher plant. (Though as it turns out, there are more than 600 carnivorous plants across a dozen genera – who knew?! Time to start shopping for a butterwort… )

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In third grade Claire had done a wonderful school project that included learning about and drawing these plants, but she had never seen most of them in person, and was fascinated by all the varieties the shop had on display. The sundew she picked is a lovely Drosera Adelae. And the pitcher plant is labeled a Sarracenia Leucophylla – though it’s likely a hybrid; true Leucophyllia, a native of the US gulf coast, are supposed to have very white pitchers. (Both our plants were cultivated by Courting Frogs Nursery in Stanwood, Washington).

Our pitcher plant, a <i>sarracenia leucophylla</i> hybrid.

Our pitcher plant, labeled a Sarracenia Leucophylla.

Of the three, the sundew is indeed best suited to catching fruit flies, which have continued their little red-eyed reproductive frenzy in our food scraps bin. Per the shop’s instructions, all three plants have been living on a sunny windowsill, but when I parked the sundew near the kitchen scraps, several of the circling fruit flies got promptly snagged in its sticky drops of mucilage.

FruitflyBright480

I confess, annoying as the fruit flies are, it did tug at my heartstrings just a little bit to watch through my macro lens as this little guy struggle against the sticky predicament in which he found himself. Fruit flies don’t seem to be quite large enough to trigger the sundew’s movement response, in which they will actually wrap a fly in their sticky protrusions, so this guy just gradually struggled himself into more and more of a sticky bind.

FruitflyECU_480

Our carnivorous trio has not exactly brought our fruit flies under control, but they have been fun to learn about with Claire. Did you know that sundews (the genus Drosera) are a large family with over 180 plants, examples of which can be found almost everywhere in the world? Or that they need bright sunlight because they are so covered with fly-trapping appendages that they are weak photosynthesizers? Or that the sticky stuff is mucilage, like you find in aloe vera, or in okra, or on envelopes?

Here in the northwest we have a native, Drosera Angelica, whose range includes Washington. We’ll have to keep an eye out next time we’re in a bog!

pest control

7 Comments so far ↓

  • Jason

    My Sarracenias are all excellent against yellow jackets. And earwigs. Those lovely pitchers are always filled to the brim with decaying yellow jackets. Keep them away from flowers, as honeybees are attracted to the nectar these plants secrete. Not sure if you know, but keep your US native carnivores outside for the winter. Keep them moist, and protected from cold below 30 degrees (I keep mine on a sunny concrete porch next to the brick wall). They’ll come right back next spring ready for more!

  • matthew

    hey u know that thing u call your project thats a lie someone in my class named kabir did the same thing u did.lier

  • Washtana

    John;
    That was very funny! Nothing like a little N.T. humor to make day a little brighter.

  • Brendan Lovering

    Wow. I never thought of using pitcher plant to get rid of fruit flies. I think I will get myself one of these. I use to have a spider who would get all my house files. She had her web in the corner of the window and when ever there was a fly in my house, I would turn a nearby light on and the files would fly to the light and get caught in her web. It worked really well. Looking forward to seeing how well the pitcher plant works. You don’t need to feed it flies if it doesn’t get any do you?

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