Dealing with pests

[radhatter]

I thought this hobby was supposed to be relaxing but the pests this spring are making it anything but relaxing.

So far I’ve had spruce aphids do a ton of damage to my Engelmann spruce yamadori and I just caught sign of them spreading to my Ezo spruce forest (caught it early at least).

I also found frass from wood boring insects in large two hinoki cypress I got in the bargain bin last fall, but now I know why they’ve been sulking at least. I think this may be the culprit? Anyone recognize it?


These pests are driving me nuts. What is everyone else’s routine for dealing with this kinda stuff?

 

[hemmy]

It is definitely at the scene of the crime! It looks like a Phyllobius or Polydurus weevil which seem to feed on leaves. But I did find a reference to them boring cavities under bark, presumably to lay eggs. How deep are the holes? If they are shallow, maybe it is the green guy. I would spray some permethrin into them. Maybe try and capture one to send to the county extension office for ID.

Best of luck!

 

[pandacular]

If this beetle is only attacking your spruce, it would suggest it being spruce beetle, Dendroctonus k. Here’s some literature from the USFS on it, which has a picture that seems close enough for my non-entomologist to make it a good enough guess.

https://www.fs.usda.gov/foresthealth/docs/fidls/FIDL-127-SpruceBeetle.pdf

The recommended treatment is carbaryls and pyrethroids, but that would be somewhat dependent on a proper ID.

 

[Shibui]

These pests are driving me nuts. What is everyone else’s routine for dealing with this kinda stuff?

Pests can drive us crazy when they get out of hand. Usually that's because we don't know the first signs so they have to get out of hand before we recognise there's a problem. Knowing what to look for means you can take steps BEFORE the pest starts causing real problem.
I'd bet the Spruce aphids won't get a chance at your place again, and you'll be checking every trunk for the first signs of borers.

Gradually we learn what pests are a problem in our area and what to do about them. When you get to that stage you don't have a real problem any more.

Some growers, including most public collections, use prophylactic treatment which means they spray a broad spectrum pesticide a couple of times each year whether they see pests or not, just in case.
I use pesticide if I really need to, but prefer to leave low numbers of pest species alone. That can encourage natural predators which can help us deal with the pests for free. As a bonus less toxic chemicals in our environment.
Pest problems can vary depending on location. Growers close to forest will have some pests moving in from adjoining areas. Growers with extensive gardens nearby may have a similar pool of pests close by waiting to move in. Apartment dwellers may be more protected by their trees being isolated from a source of pests. We all need to be wary of introducing new problems on trees we purchase.
I guess the answer to your dilemma is the usual bonsai answer - it depends - on your philosophical stand on chemical use, where you live, what species you grow, etc.

 

[radhatter]

It is definitely at the scene of the crime! It looks like a Phyllobius or Polydurus weevil which seem to feed on leaves. But I did find a reference to them boring cavities under bark, presumably to lay eggs. How deep are the holes? If they are shallow, maybe it is the green guy. I would spray some permethrin into them. Maybe try and capture one to send to the county extension office for ID.

Best of luck!

Good graphic! I think that guy is some sort of weevil but I’m not convinced it’s the culprit. Could be wrong place wrong time. Either way I treated with a systemic and we’ll see if these trees recover. I’m mostly kicking myself for bringing in this pest into my garden. I’m not seeing any sap come out of the boreholes which I assumed would happen, though I’m not certain. Worried that could be a sign these trees are toast. Hopefully they didn’t spread…