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European sawfly on mugo pine #879027

Asked July 27, 2024, 3:44 PM EDT

Can I use neem to protect my mugo pine that has been infested with European sawflys for the past 3 years? I have picked the larve off after seeing them (wiggle worms) but I would rather treat the tree. Is there something I can add to the neem to make it more effective? Also, can I treat the soil beneath the tree where the larvae over-winter?

Chittenden County Vermont

Expert Response

Good Morning Craig,

Thanks for reaching out! I've added Ann Hazelrigg, the director of the State Plant Diagnostic Clinic to this chat so that she can advise you on the use of Neem to protect your mugo pine.

Are you able to send us some photos of the damage? Photos of the larvae would also be helpful!

Cheers,Ricky, UVM Extension Master Gardener Volunteerwww.uvm.edu/extension/mastergardenerWe do not intend to endorse any products we mention or criticize products we do not mention. When we include a link to a resource that recommends a chemical, it is for informational purposes only; the chemicals may not be registered for use in Vermont. Replied July 30, 2024, 7:14 AM EDT
Ricky and Ann,
One more photo of the tree.
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On Tue, Jul 30, 2024, 7:14 AM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied July 30, 2024, 8:10 AM EDT
Hi Rcky and Ann,
I just took pictures of some of the damaged limbs and one of an undamaged limb.  I was pretty successful in removing the larvae this year but there was still some new damage, and it was a many day affair that consumed many hours.
I'm hoping for a simple solution. 
I don't have pictures of the larvae, but they matched exactly the description and photos, and behavior of, the masses of "wiggle worms" that stood on end when disturbed.  The needle damage also matched the photos, displaying the tiny brown semicircles, evenly spaced, lined up on the edge of each needle.
I hope this is enough information for you to be able to advise me.

Thank you,
Craig 


image

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On Tue, Jul 30, 2024, 7:14 AM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied July 30, 2024, 8:10 AM EDT

Hi Craig,

Thanks for sending those photos! That definitely matches the description of sawfly.

Here's some guidance from Ann Hazelrigg:

This can be a voracious pest! Spinosad may be a more effective alternative organic insecticide. Best to watch and treat the small larvae. Neem can also be used. https://hort.extension.wisc.edu/articles/european-pine-sawfly/
I would not recommend systemics.

I hope this helps! Good luck with your beautiful pines!

Cheers,Ricky, UVM Extension Master Gardener Volunteerwww.uvm.edu/extension/mastergardenerWe do not intend to endorse any products we mention or criticize products we do not mention. When we include a link to a resource that recommends a chemical, it is for informational purposes only; the chemicals may not be registered for use in Vermont. Replied July 30, 2024, 1:32 PM EDT
Thanks!
I'm going to take your advice!

On Tue, Jul 30, 2024, 1:32 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied July 30, 2024, 2:23 PM EDT

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