Q/A #27 - Carnivorous Plants for Fruit Flies?

QUESTION:
What kind of plant would you recommend for fruit flies indoors? Yes, it's winter and we have fruit flies. The flies don't get caught by my sundews.
(Submitted in January 2021.)

RESPONSE BY JEFF DALLAS:
We don't advocate using carnivorous plants because a lot of growers mistaken insects as a source of energy for these plants and forget about lighting. As long as you understand that lighting is the source of a plant's energy and not insects, there are a few plants you can try.

No guarantees on this, but try a Mexican butterwort (Pinguicula), preferably one that doesn't go dormant in winter. These might include  P. Aphrodite, P. Alfred Lau, P. gigantea, and P. moctezumae x gigantea. They are a butterwort with long leaves and if anything would catch them it would be those. 

Two other plants I know that will catch them are unexpected, but  Sarracenia leucophylla and S. alata will catch them. If you happen to have either of those plants growing outside, and they still have some leaves on them, try bringing them in overnight. Set a small lamp over them overnight in the area where the fruit flies are a problem. By morning the pitcher plants will have caught quite a few. Just make sure to put the Sarracenia back outside to complete their winter dormancy. 

Also make sure that these are fruit flies and not fungus gnats. Fungus gnats are mostly black and tiny, and are very common in the soil of other houseplants, which will require a different form of treatment. Fruit flies are a little bigger, often with red eyes and are going to be drawn to produce.

As mentioned before, sunlight is a plant's source of energy. Insects are only forms of fertilizer. Whatever plants you attempt to use, make sure it is always getting the recommended lighting.

• Submitted in January 2021. The original question and response have been edited for publication.
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