Arbor vitae bugs

Asked July 11, 2020, 5:49 PM EDT

I planted a row of arbor vitae trees last year. This year, I planted a row of Woodward Globes. Both sets of plants are teeming with tiny bugs that fly around in swarms whenever I approach the plants. I don't think I see any visible damage to the plants yet, but would like to know what they are. If they pose a danger to my plants, I would like to know what treatment works best.

Alcona County Michigan

4 Responses

Are you able to get a photo or two and add it to this message?

First photo shows webbing that is on some plants. Second shows what appears to be a mayfly. We have several of them. In addition, we have lots of small flying insects. I tried to photograph them, but they are so small (and fast) that I couldn’t.

Hello. I have been looking carefully at your photos and do not see anything that is causing concern. Do the trees look generally healthy to you? There could be a possibility of spider mites and the way to find out is to take a white sheet of paper, hold it under some branches and give the branches a shake. If black moving dots fall on it there are likely spider mites. Mites can also cause webbing or perhaps spiders are there - which is a good thing - as they often eat other more damaging insects. Another possibility are arborvitae leaf miners, which live inside the leaves and make tunnels while they grow. These can be discovered by holding up branches to a strong light to see if there are tunnels. Another possibility is that it was a temporary occurrence and insects have moved on. I hope this helps.

Thank you for a most helpful response.