A single caterpillar causes a large mass of pitch.
Pitch mass borers feed on pine resin, and do not bore into the tree. But bad infestations do cause the tree to spend energy producing the large amounts of sap...
The pitch mass borer most commonly found in Utah is the sequoia pitch moth.
Lilac ash borer exit holes are easily visible, and perfectly round.
Lilac-ash borers can attack lilacs, causing dieback.
Honeylocust pod gall midges overwinter in cocoons in the soil or bark crevices, and emerge on warm spring days.
Larval feeding causes the leaves to swell, protecting the midge larvae inside.
The honeylocust borer adult is a beetle, and the larvae feed in meandering trails under the bark.
The exit holes of honeylocust borers are D-shaped.
Ash leaf curl aphid feeds in large colonies within tightly curled ash leaves.