Inch Worms on Collected Pine

[Josh88]

While watering this morning I noticed just one small branch on a collected lodgepole pine covered in inch worms. I assume they are feeding on some kind of pest, so I removed the branch. Any ideas of what would have caused this one branch infestation and what they might be feeding on? I’d like to be proactive to keep whatever this is from spreading.

 

[Wires_Guy_wires]

Looks like red headed pine sawfly, they feed on the needles.
You could have picked them off and saved the branch, something I do with sawfly larvae.

 

[PiñonJ]

Since they are caterpillars, I would assume that they are the pest.

 

[Josh88]

Since they are caterpillars, I would assume that they are the pest.

Any idea what might draw them all to just one branch?

 

[Josh88]

Looks like red headed pine sawfly, they feed on the needles.
You could have picked them off and saved the branch, something I do with sawfly larvae.

This was a very weak branch to begin with that would have gone anyway when I design the tree, so I chose to just get rid of whatever attracted them to it.

 

[Paradox]

Sawfly larvae, kill them with impunity.
They will eat the older foliage on that branch.

Sawflies lay thier eggs in the branch of pines and other trees.
The larvae emerge and eat the needles

Know your enemy:

Sawfly - Wikipedia

en.wikipedia.org

 

[coh]

Any idea what might draw them all to just one branch?

That's where the eggs were laid. Now whether there is a good reason why the moth laid the eggs there as opposed to other branches, I have no idea.

Sawfly larva (which is what these look like) tend to feed in groups. They also exhibit an interesting behavior where they will all move in unison if they feel threatened. Hard to describe but very dramatic if you see it happen.

 

[Josh88]

Sawfly larvae, kill them with impunity.
They will eat the older foliage on that branch.

Sawflies lay thier eggs in the branch of pines and other trees.
The larvae emerge and eat the needles

Know your enemy:

Sawfly - Wikipedia

en.wikipedia.org

Thank you

 

[Josh88]

That's where the eggs were laid. Now whether there is a good reason why the moth laid the eggs there as opposed to other branches, I have no idea.

Sawfly larva (which is what these look like) tend to feed in groups. They also exhibit an interesting behavior where they will all move in unison if they feel threatened. Hard to describe but very dramatic if you see it happen.

I hope they move en masse far away from my trees!

 

[coh]

I hope they move en masse far away from my trees!

They won't! We had them on a mugo (in the ground) and they basically removed all the old needles within a week or so.

I've had them on bonsai a few times but now keep an eye out for them. They can do a lot of damage in a hurry.

 

[CWTurner]

Since they are caterpillars, I would assume that they are the pest.

They are actually maggots. Sawfly larva.
First time I saw them, I also thought they were caterpillars and treated them with BT. Waited a couple days and they had eaten half my pine bed. BT won't work as they are NOT caterpilars.
CW

 

[PiñonJ]

They are actually maggots. Sawfly larva.
First time I saw them, I also thought they were caterpillars and treated them with BT. Waited a couple days and they had eaten half my pine bed. BT won't work as they are NOT caterpilars.
CW

Yeah, I posted before I saw Wires-Guy’s post ID’ing them. The OP thought they were inchworms, which are caterpillars. At any rate, either one is a pest!

 

[Brian Van Fleet]

Destroy them!

 

[sorce]

Set a calander alarm on your phone to check for them next year at this time.

Maybe do a go back and see when the eggs were laid too.

This way you can prevent it.

Sorce

 

[Leo in N E Illinois]

You need to get rid of them, they can do a lot of damage. The ones you see are easy to kill, just pick them off.

The problem is, if you have a few, you probably have many, hiding on your other pines. Bring out the big guns, go on a sawfly larva hunt.

When selecting a pesticide to use, be certain the label lists sawfly. If the label does not specifically list sawfly, then there is no guarantee it will work.

As above, BT works on caterpillars (lepidopterans) but not on fly larva (Dipterans).
Some organic options, there are Spinosaids that work of Dipterans in organic formulations for household use. On the farm we use Entrust, labelled organic, but that label might not be approved for household use even though it is organic.

CHeck out the avermectins, another group of organic pesticides that may have some labelled for household use.

WHat is approved varies from state to state and country to country, so I do not list specific brand names. You will have to do your homework to get your local list of approved chemicals.