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…

 

[Ozz80]

I spray a mix of non-toxic pest control materials (neem oil, liquid soap, olive oil and potassium carbonate) to my garden monthly for preventive control from March to the end of October. For the infestations, neem oil alone can solve aphids, but multiple applications are required (3 or more). I use pesticides only as a last resort, if neem oil does not work.

 

[Ozz80]

I also have planted a rosebush near the spot where I hold my bonsai candidates. I heard that rosebushes are magnets for pests and fungal diseases and for that reason, they are planted on vineyard rows in order to alert infestations / diseases.

I don't know whether that will work or not though. . At least it looks and smells nice.

 

[radhatter]

I happen to have roses by my bonsai, so far they have powdery mildew and the trees don’t (but sprayed them for it anyway) and my spruce has aphids but my rose doesn’t… so mixed success but doesn’t hurt!

 

[Paradox]

I use pesticides when I have to. I have some trees I've had for 14 years now and some I've spent some coin on. Not willing to risk them with treatments that might not work. Enough can go wrong as it is that it's just not worth rolling the dice.

@Ozz80 be careful spraying neem or any other oil when it's hot and sunny. You can actually burn your trees

 

[Ozz80]

I use pesticides when I have to. I have some trees I've had for 14 years now and some I've spent some coin on. Not willing to risk them with treatments that might not work. Enough can go wrong as it is that it's just not worth rolling the dice.

@Ozz80 be careful spraying neem or any other oil when it's hot and sunny. You can actually burn your trees

I spray late afternoon when the heat is over and wash the plants early in the morning in summer days. Doing this for a few years, nothing is burned so far.

 

[Ozz80]

I use pesticides when I have to. I have some trees I've had for 14 years now and some I've spent some coin on. Not willing to risk them with treatments that might not work. Enough can go wrong as it is that it's just not worth rolling the dice.

@Ozz80 be careful spraying neem or any other oil when it's hot and sunny. You can actually burn your trees

Actually after your warning, I quickly checked the internet about neem oil and I understand there is a lot of debate around that. My primary reason for using organic non poisonous material is, neighbors' kids come and go to my garden without warning from time to time while playing . There are also lots of stray cats and small animals like hedgehogs or birds that visit my garden and I don't want to harm them.

Since I understand that this issue is controversial, I have to add that anyone to use them is to do that at their own risk.

I will also be thankful if anyone can suggest altenative pesticide which have no risk for humans and nature.

 

[Paradox]

Actually after your warning, I quickly checked the internet about neem oil and I understand there is a lot of debate around that. My primary reason for using organic non poisonous material is, neighbors' kids come and go to my garden without warning from time to time while playing . There are also lots of stray cats and small animals like hedgehogs or birds that visit my garden and I don't want to harm them.

Since I understand that this issue is controversial, I have to add that anyone to use them is to do that at their own risk.

I will also be thankful if anyone can suggest altenative pesticide which have no risk for humans and nature.

You don't need to explain or justify your choice of treatments. They are your trees, your property, your choice.

 

[radhatter]

If you can’t win with need oil, what can you win with? I’m going with imidacloprid because I agree with Paradox, these trees are too precious to be messing around with something that doesn’t work. I’ll try to protect the bees though at least

 

[Paradox]

If you can’t win with need oil, what can you win with? I’m going with imidacloprid because I agree with Paradox, these trees are too precious to be messing around with something that doesn’t work. I’ll try to protect the bees though at least

Just don't use it on anything flowering and the bees should be ok.

 

[radhatter]

Just don't use it on anything flowering and the bees should be ok.

That’s the plan, my new azalea came with scale so I’ll be using it on that but removing the flowers

 

[shohin_branches]

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?
View attachment 596364

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

Do a lime sulfur dormancy spray in winter. It kills the pest eggs that are overwintering on your trees. Those eggs hatch and the infestation starts when your leaves are really young and tender.

 

[radhatter]

Do a lime sulfur dormancy spray in winter. It kills the pest eggs that are overwintering on your trees. Those eggs hatch and the infestation starts when your leaves are really young and tender.

What’s the dilution for this? Spray down the whole tree?

 

[Shibui]

I spray a mix of non-toxic pest control materials (neem oil, liquid soap, olive oil and potassium carbonate

Any pest control is, by definition, toxic. These substances are designed to kill pests. The only difference is that humans are much bigger than most of the pests so can survive the toxicity.
The correct term should be low toxicity pest control materials.
Even these low toxicity pest control substances can be toxic to beneficial insect predators which puts us at more risk of pests multiplying before predators can help control numbers.
Also do not confuse 'organic' with low or non toxic. There are many very toxic organic substances.

What’s the dilution for this? Spray down the whole tree?

Just checked online and found 30:1 is the recommended mix for winter spray or dip for bonsai. You'll need to convert that to whatever sized container you plan to mix or spray with.
If you purchase horticultural lime sulphur it will have recommended mixing rates and warnings on the container.
Correct, spray the entire tree to make contact with any bugs, eggs or fungal spores. I have seen article from a Japanese nursery where they turn the tree upside down and dip the entire tree (not pot or soil) into a container of mix instead of spraying.

 

[radhatter]

Any pest control is, by definition, toxic. These substances are designed to kill pests. The only difference is that humans are much bigger than most of the pests so can survive the toxicity.
The correct term should be low toxicity pest control materials.
Even these low toxicity pest control substances can be toxic to beneficial insect predators which puts us at more risk of pests multiplying before predators can help control numbers.
Also do not confuse 'organic' with low or non toxic. There are many very toxic organic substances.


Just checked online and found 30:1 is the recommended mix for winter spray or dip for bonsai. You'll need to convert that to whatever sized container you plan to mix or spray with.
If you purchase horticultural lime sulphur it will have recommended mixing rates and warnings on the container.
Correct, spray the entire tree to make contact with any bugs, eggs or fungal spores. I have seen article from a Japanese nursery where they turn the tree upside down and dip the entire tree (not pot or soil) into a container of mix instead of spraying.

Ya… I’m beginning to see why they might do that
I’ll try and remember this going into winter, sounds like something I’m going to want to do next winter