Spruce trees turning rusty.

[ChoppyChoppy]

I've got about 40 spruce trees that I planted about 6 years ago as a "live fence" (separates my land from the 2 neighbors). They are in the area of 2-4ft tall now.

I've got several that are turning rust/orange/red in the middle of the tree. The ends are still green and none of the needles are falling off.

 

[Raintree]

Needle rust

Mites

As arborists, this is why we carry a lens.

 

[ChoppyChoppy]

Needle rust

Mites

As arborists, this is why we carry a lens.

I went to take a pic last night and they somehow healed themselves since last week. I noticed it a few weeks ago and meant to take pics and ask and I had forgotten.

 

[ChoppyChoppy]

Peectures

 

[Raintree]

Looks like the air breathing arthropods we call arachnids.

 

[ATH]

I'd bet you have some of both. The Rhizosphaera infected needles probably dropped - that is why it looks like it "healed". Then the spider mite damage is showing up as it gets hot and dry.