My Ming Aurelia seems to have tiny black flies in the soil. They fly around the apartment and are quite annoying. How can I get rid of them?
Thank you for contacting the Toronto Master Gardeners. It sounds like these flies are fungus gnats, although I can’t be certain without a photo. In small numbers, fungus gnats are more of a nuisance than a true pest. It is the larvae (tiny and silver/white/clear in colour) that can cause damage the plants. They feed on fungus and decayed organic matter in the soil, as well as roots and root hairs.
Fungus gnats can live in the soil of any houseplant, so you might want to consider isolating your Ming Aurelia (Polyscias fruticose) while you get the insects under control, so that they do not spread to other plants that you might have.
The most important thing to do to manage these insects is to change the soil moisture conditions for your plant. Watering should be limited so that the top two inches of the soil surface can dry between deep waterings. The soil should provide good drainage, and the pot should have a drainage hole. Ming Aurelia performs best in soil that is not too dry and not too wet, and it requires bright indirect light. Watering needs to be adjusted depending on the amount of bright light it gets, and it will require less water during the winter.
If the soil for your Ming Aurelia is heavily infested with fungus gnats, it might be a good idea to repot with fresh soil that does not have high organic matter content.
Below is a link to further information on fungus gnats. Please note that the information about pesticides (chemical controls) in this article applies in the US and not in Canada. The use of pesticides in Ontario for cosmetic purposes in home lawns and gardens is strictly controlled by law. The second link below contains an Allowable list of active ingredients that can be used in Ontario.
Also here is our guide for best practices for houseplants.
Best of luck with your lovely Ming Aurelia !