A few days ago I noticed dozens of small flying insects flying around my arborvitae. They move too fast and are too small to take a picture of but they are about the size and appearance of fungus gnats when flying around so that could be a possibility. You can only make out the wings when they're flying but I think they may have a black body. They're easy to miss if you don't pay attention.

I also noticed them around some yews and could see them in a neighbor's deciduous shrub nearby but I don't know the type.

Don't see them anywhere else.

A bit of snow over the winter and last year. These trees get surrounded by a lot of snow. Last year there was a small amount of leaf loss due to snow. A neighbor lost a small evergreen shrub recently from what looked to me to be disease or insect damage which has me concerned.

Sorry I couldn't be any more descriptive but any help about what flying insects might be attracted to these would be helpful. I sprayed them with neem oil a couple of days ago but today they're back. Will do a couple follow up sprays every week or so.


Went to check for scale and to be honest not sure what to look for so posting some pics. There's browning on the inside but I always thought that was due to the density on the outside restricting light.

Another odd thing was when I went to check there were only a few insects now. The trees are now in shade and before when I saw them they were in direct sunlight.

Here are the pics if it helps identify anything.

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    Look for scale, they secrete sugar which attracts insects
    – kevinskio
    Apr 15, 2015 at 20:57
  • @kevinsky not sure I can tell the difference between scale and dead needles. Added some more info and pics if you can spot any thing. Apr 15, 2015 at 21:54
  • I'd guess you had Thuja leaf miners, but it's a couple months early for their flight (at least here in PA).
    – J. Musser
    Apr 16, 2015 at 21:29
  • @J.Musser according to that link the leaf damage looks like the photo of winter damage. It's mostly at the base of the leaves. The browning of the tips I think is due to bad timing applying the neem. It was a bit too sunny to spray but they were bothering me so I sprayed then maybe an hour later rinsed the tree with plain water. The flies didn't look like leaf miners. They had clear wings and black bodies. That's all I could make out. There were some today but not nearly as many yesterday. Apr 16, 2015 at 21:40
  • Ok, then they are most likely not pests to these plants. Thanks for examining the insects. At my place, the little gnats/flies are everywhere, but not being plant pests :)
    – J. Musser
    Apr 16, 2015 at 21:43

1 Answer 1


Being the time of year I'd venture a guess that the arborvitae and yew provided the protected overwintering environment for these flies. When flies wake up and when they are newly adults they often hang out there until it warms up some more or another stimulus drives them to move.

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