Pine Pitch Borer Question

[BostonBull]

I have been studying for the MA cetified Arborist exam this fall and am learning my pests.

I found a Pine Pitch Moth/Pine Mass Borer (Synanthedon pini).

I asked ONE of our PHC guys and he says.......ah harmless throw it out. When I looked it up though it says that they bore a large hole in the tree and sit in it for up to 3 years developing.

It also stated that you would be hard pressed to find more than one in a tree though.

Soooo..................Are they harmless or what?

 

[Gate Keeper]

I'm not so sure they are harmless. The beetles (Pitch Mass Borers) actually bore test holes in to the cambium to see how much sap is flowing. That is why if you look at certain pine trees there will be multiple masses of pitch. They do this to find a weak tree. Once the weak tree is found they produce a pheromone and more beetles arrive. I have used Bidrin Injection to stop these pests, along with other pests like pine bark beetle and ambrosia beetle.

 

[woodville]

I wouldn't call them harmless especially around Cape Cod or Cape Ann. It is very hard to determine witch of the borers is actual causing the pitch mass but if it's on a clients tree it's a potential major issue. I will always error on the side of trying to eliminate the borer first, even if it doesn't kill the tree it's unsightly. Umass has a good fact sheet about them. One thing that not mentioned is the transmission of Blue Stain Fungi. I have seen this to be the actual cause of many declining or dead trees. Proper cultural practices along with a well timed bark spray or injection works well however I don't believe Merit is labled for Synanthedon pini.http://www.umassgreeninfo.org/fact_sheets/bark_beetles/conifer_bark_beetle.html

 

[Urban Forester]

I found a Pine Pitch Moth/Pine Mass Borer (Synanthedon pini).
I asked ONE of our PHC guys and he says.......ah harmless throw it out. When I looked it up though it says that they bore a large hole in the tree and sit in it for up to 3 years developing.
It also stated that you would be hard pressed to find more than one in a tree though.
Soooo..................Are they harmless or what?

Harmless, no... Threshold, maybe. Any insect that feeds in the conductive tissue of a tree is not harmless, however due to the fact that there is only one insect per mass threshold damage could take a while to occur, if ever. If you are considering treatment, target the adults. They are around the tree in early to mid July (Michigan). The larvae are well protected in the mass and unreachable by most pesticides. As with MOST boring insects, they are secondary in nature, they tend to go after trees that are weak or stressed. A full treatment program should include reducing ambient stress levels in the tree through proper cultural practices, up to and including fertilization.