What is eating my bee balm?

Asked August 3, 2020, 11:29 PM EDT

Can you give me advice on what is eating my bee balm? I have sluggo down around the stems but haven't tried anything else. I looked under the leaves but didn't find any eggs/insects. Advice? Thank you, Amanda

Multnomah County Oregon

1 Response

Whiteflies are one of those groups of flies that you manage, rather than rid the garden of. Keep the numbers within moderate levels. Usually, significant populations are required before much plant damage is sustained. However, if your group of plants is having a large infestation you should bring down the white fly population by removing and disposing of heavily infested leaves. This removes the adults (flying) and the nymphs and eggs. The goal in management is to keep the numbers at a tolerable level. White flies have many natural enemies, and often the numbers of white flies increases because populations of natural enemies go down, due to insecticide use or other factors.

When did you notice the whitefly population increase? Are all your plants affected?

Keep the plants appropriately watered. Do not over fertilize the plants, white fly populations increase when high nitrogen fertilizers are used, because of the soft tender growth high nitrogen fertilizer stimulates. Prune plants as needed to encourage bushier form.

The best program to control whitefly is to prevent the build-up of whitefly populations early in the season. Remove infested leaves and dispose of them in the trash. Hose flies off the underside of the leaves. Sticky yellow traps will trap adults, but nymphal stages and eggs remain on the undersides of the leaves, so the traps are more of an indication of the infestation level than a control method. Avoid insecticides, their use will backfire when they destroy the insects preying on white flies.

This article has additional information on identification of various white flies and control, Whiteflies http://ipm.ucanr.edu/PMG/PESTNOTES/pn7401.html