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What is a white gooey mass (about 3" diameter) that is coinciding with a fly infestation. #875150

Asked June 28, 2024, 4:49 PM EDT

We suddenly have a fly infestation. We have a Ponderosa Pine next to where the infestation seems the worst. The fly trap we set up was completely full after several days. Due to the heat, there was a horrible smell coming from the tree. I discovered a white gooey mass. I sprayed it with a vinegar water solution and the next day there were no flies in the trap. However, today, flies are starting to fill the trap. I scraped the mass off and have it in a plastic bag. I I am attaching the photo. We think it is either maggots that made a home in the trunk of the tree or some sort of fungus on the tree that is drawing the flies. ANY help will be most appreciated. If the tree is sick, we want to do everything we can to save it. Thank you so much!!

Deschutes County Oregon

Expert Response

Hi Nan,

Thanks for the photo.  The mass on the photo looks like it is due to the larva of the sequoia pitch moth which is common in central Oregon.   The pitch moth larva feeding causes the tree to produce resin that forms a mass on the the bark.  

Here is a link for more information: 

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7479.html

Based on the photo, it looks like it is a young pitch mass and as you will read in the article, the larva are usually beneath the pitch mass in bark cavity. 

If you feel this is inconsistent with what you are seeing on your ponderosa and/or have any further questions,  please reach out!

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook


An Ask Extension Expert Replied July 03, 2024, 12:04 PM EDT
Oh, my goodness!  Thank you!!!  This makes perfect sense.  I really appreciate the time you spent with this.

Happy 4th!

Nan

On Jul 3, 2024, at 9:04 AM, Ask Extension <<personal data hidden>> wrote:


The Question Asker Replied July 03, 2024, 1:09 PM EDT
Greetings.  This article has been hugely helpful for accurately identifying the white goopy mass.  Unfortunately we are discovering this in other trees in our neighborhood.  One of the mature ponderosas has many of these masses and a huge amount of pitch dripping down the trunk.  Whole branches are turning brown.  Is this killing the branches and ultimately the tree?  It is on an incline and many of the masses are too high to reach with a ladder.

Also, we've noticed the appearance of a lot of what look like fruit flies.  Is it possible they are also hatching from under the masses?

Thanks so much.  

From: ask=<personal data hidden> on behalf of Ask Extension
Sent: Wednesday, July 3, 2024 9:04 AM
To: Nan Caruh
Subject: Re: What is a white gooey mass (about 3" diameter) that is coinciding with a fly infestation. (#0145068)
 

Dear Nan, here's the response to your question:

Hi Nan,

Thanks for the photo.  The mass on the photo looks like it is due to the larva of the sequoia pitch moth which is common in central Oregon.   The pitch moth larva feeding causes the tree to produce resin that forms a mass on the the bark.  

Here is a link for more information: 

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7479.html

Based on the photo, it looks like it is a young pitch mass and as you will read in the article, the larva are usually beneath the pitch mass in bark cavity. 

If you feel this is inconsistent with what you are seeing on your ponderosa and/or have any further questions,  please reach out!

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook



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The Question Asker Replied August 13, 2024, 2:34 PM EDT

Hi Nan, 

Many ponderosa pines here have pitch masses from the Sequoia Pitch Moth.  Usually mature trees can withstand the moth with little to no impact on their survival.  There is the possibility though of  limb dieback:  https://extension.usu.edu/planthealth/research/sequoia-pitch-moth  

It's the smaller trees that are at greater risk of damage.  Unfortunately I  had a younger ponderosa succumb this year.  The limbs that exited from the trunk where pitch masses were located started dying first. Then the entire tree turned brown. 

Feel free to email photos of the pine in question. Is it receiving any irrigation?

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook

An Ask Extension Expert Replied August 22, 2024, 12:40 PM EDT

Hi Nan, 

Fruit flies nesting habits include decaying organic material, vegetables and fruit. material. https://extension.usu.edu/planthealth/ipm/notes_nuisance/fruit-flies

I can't find any information that supports them utilizing pitch masses. If you have photos of the flies, feel free to email them and I can take a look.


Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook

An Ask Extension Expert Replied August 28, 2024, 2:15 PM EDT

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