Help! Massive Juniper Scale(?) Infestation!

[Mellow Mullet]

Imidacloprid is not generally recommended for use on armored scale because it is ineffective. So says basically all the scale IPM sheets from any extension service. I am open to the possibility that it is effective in bonsai culture vs landscape, but want to know: do the people espousing it’s use have personal experience in which imidacloprid, used by itself, conquered an armored scale infestation?

Also: Horticultural (dormant) oil definitely causes a stark color change to a Juniperus procumbens from blue-green to emerald green. I have never used it on a San Jose, so I cannot attest to the color effect.

I have used it successfully to kill scale on japanese magnolia and magnolia fiscatti, both in a bonsai pot and in the landscape. I have also used it to kill spider mites on junipers, but I prefer Avid for that. I use this particular one: https://www.lowes.com/pd/BAYER-ADVA...VStyGCh2TRwOOEAQYAyABEgLHO_D_BwE&gclsrc=aw.ds

It works because it is a systemic and used as a soil drench, the roots pick it up and circulate it throughout the plant and when the scale insects feed on the plant the get some of the poison. Scale insects aren't hard to kill once you get past the scale part, the is why most sprays (contact poisons) don't work.

I would hesitate to spray any type of dormant oil on trees when spring/ summer is here. They are more of a winter treatment.

 

[sorce]

Just remember that this "nuclear" method only works till it doesn't.

This is where I'd enter again, the argument for TRUE sustainability....

But I'd still burn it.

A cabinet full of insecticides is a false sense of security.

Plus, when you die, and the next person doesn't use it, the bitch ass trees we created die too.

Sorce

 

[InstilledChaos]

I have used it successfully to kill scale on japanese magnolia and magnolia fiscatti, both in a bonsai pot and in the landscape. I have also used it to kill spider mites on junipers, but I prefer Avid for that. I use this particular one: https://www.lowes.com/pd/BAYER-ADVA...VStyGCh2TRwOOEAQYAyABEgLHO_D_BwE&gclsrc=aw.ds

It works because it is a systemic and used as a soil drench, the roots pick it up and circulate it throughout the plant and when the scale insects feed on the plant the get some of the poison. Scale insects aren't hard to kill once you get past the scale part, the is why most sprays (contact poisons) don't work.

I would hesitate to spray any type of dormant oil on trees when spring/ summer is here. They are more of a winter treatment.

Magnolia scale is a different beast. That is a soft scale, which Imidacloprid is effective in controlling. Juniper scale is generally armored scale, against which Imidacloprid is said to be ineffective.

 

[sorce]

armored scale,

The systemic circumvents the armor.

As eating poison will kill us, even wearing armor.

Sorce

 

[Mellow Mullet]

Magnolia scale is a different beast. That is a soft scale, which Imidacloprid is effective in controlling. Juniper scale is generally armored scale, against which Imidacloprid is said to be ineffective.

The scale that was on my magnolia was a hard scale. A systemic works because it does not have to penetrate the armor. Please look up the difference between systemic and contact insecticides.

 

[TheEmpireNeverEnded]

[

 

[TheEmpireNeverEnded]

I'll post my results

 

[Oleg]

I like what AJL suggested, soap does as oil does, fatty acids coat and suffocate, once submerged there will be some pressure to push the point home. I have never used soap only because of the word detergent (dish washing) being different than soap (Ivory). Now I know thanks.

 

[Leo in N E Illinois]

Whelp, I ordered the bonide version of what you recommended. I wonder if there's a best time of year to begin applying it, or if I can apply it in tandem with the horticultural oil that I also ordered.

The best time to apply imidacloprid is yesterday. Given that opportunity has passed, use it today. You need to kill of the pests NOW, not tomorrow.

Yes, you can use oil, soap sprays and other things at the same time. But remember, other sprays will wash off the imidacloprid, so do what ever, then the last thing you do today is apply the imidacloprid. If the tree is sentimental to you, don't waste time, this thing is past the point of the "being gentle" will help in time to save the tree. Scale can increase their populations exponentially, you need to act now, not later.

At least this is my opinion. I am not an "all knowing deity", so do what your personal judgement says it best. If you are lucky, the soap solutions will work. I mention the imidacloprid, because its success rate is high, you asked the question, and that is what I would do.

 

[Mellow Mullet]

The best time to apply imidacloprid is yesterday. Given that opportunity has passed, use it today. You need to kill of the pests NOW, not tomorrow.

Yes, you can use oil, soap sprays and other things at the same time. But remember, other sprays will wash off the imidacloprid, so do what ever, then the last thing you do today is apply the imidacloprid. If the tree is sentimental to you, don't waste time, this thing is past the point of the "being gentle" will help in time to save the tree. Scale can increase their populations exponentially, you need to act now, not later.

At least this is my opinion. I am not an "all knowing deity", so do what your personal judgement says it best. If you are lucky, the soap solutions will work. I mention the imidacloprid, because its success rate is high, you asked the question, and that is what I would do.

What he said! It's not like you have seen just a couple of scale, they have almost sucked the like out of your tree. They don't need a good bath in soapy water and then some body oil to shine up their scaly armor. Poison them.

 

[Wires_Guy_wires]

Just remember that this "nuclear" method only works till it doesn't.

This is where I'd enter again, the argument for TRUE sustainability....

But I'd still burn it.

A cabinet full of insecticides is a false sense of security.

Plus, when you die, and the next person doesn't use it, the bitch ass trees we created die too.

Sorce

True sustainability can't be done in a pot for more than a season, which is winter, when we lay down all practices for some time.
Water is a bug repellent too, a healthy plant is both an attraction as well as a repellent.

A cabinet full of insecticides is a safety net for when all else fails. I think this is a case where all else has failed and the tree needs a boost. It mite (ha!) never need treatment again if gets healthy enough to withstand the damage these bugs do.

Nonetheless, I culled 40 black pines today because they can't handle my back yard, and 30 thuja because I think they suck. I agree on the point that the weaker plants have no right to survive in a pot if they need constant treatment. I'm a red pine guy now!

 

[AJL]

Are you sure Imidacloprid is approved/ passed for domestic use in gardens and in particular on Juniper in USA ?!!

 

[AJL]

Imidacloprid a Neonicotinoid and is linked to neurotoxic, reproductive and mutagenic effects. It has been found to be highly toxic to bees and other beneficial insects. It is also toxic to upland game birds, is generally persistent in soils and can leach to groundwater. I wouldnt really want to be using it in my garden as other safer alternatives are available, but you guys know best what works for you LOL!!!

 

[Oleg]

"It has been found to be highly toxic to bees and other beneficial insects. It is also toxic to upland game birds, is generally persistent in soils and can leach to groundwater."

That is pretty well par for the course, they are all very toxic to bees, birds, fish and amphibians, you do not spray in the wind or around water. I was wondering what the other guy was going to do with a bucket of insecticide after treating the tree.
Also if you use systemics you need to keep the wildlife off the fruit, possibly cut the flowers too.

 

[InstilledChaos]

The scale that was on my magnolia was a hard scale. A systemic works because it does not have to penetrate the armor. Please look up the difference between systemic and contact insecticides.

I am aware of the differences between systemic and contact insecticides. If you “look up” IPMs for armored scale, they ALL say Imidacloprid is ineffective in controlling armored scale, despite it being a systemic. Again, I am completely open to the cultural difference between bonsai and landscape leading to a difference in effectiveness. I am simply asking if anyone has experience pointing to effectiveness of Imidacloprid vs armored scale (ideally in junipers), which would be really helpful for many people. This is especially true since almost every credible resource on a google search of the topic says the exact opposite. I can tell you that “look it up, dummy“ responses are not helpful to anyone.

Here is an example of what university extension services say about Imidacloprid and armored scale:

Armored Scale Insects & Control

Many armored scales are serious pests of ornamental shrubs, trees, groundcovers, and turfgrasses in South Carolina. Almost 40% of the Clemson Plant...

hgic.clemson.edu

From what I gather, it is not effective in this case because armored scale feed from the plant’s cambium, and Imidacloprid does not easily penetrate into these tissues. Conversely, soft scales feed on the phloem, where the chemical is abundant.

 

[Paradox]

I would just dowse it with Sevin spray. Ive used that on scale in the past and they were gone pretty quickly.

The tree has a decent trunk and nice movement. Its worth trying to save IMO

 

[AJL]

I would just dowse it with Sevin spray. Ive used that on scale in the past and they were gone pretty quickly.

The tree has a decent trunk and nice movement. Its worth trying to save IMO

Ah Sevin!! active ingredient Carbaryl:- The insecticide carbaryl, is striking because its use has been associated with such a large number of health problems. From acute toxicity, suppression of immune system functions, and behavioral problems to cancer, genetic damage, and reproductive problems in both males and females, carbaryl's adverse effects span an enormous range.

 

[Leo in N E Illinois]

@AJL
The "BONIDE" product the OP, @TheEmpireNeverEnded , mentioned IS LABELED for home, outdoor use. The OP is not breaking any USA laws. This is just an emergency use, small quantity for backyard use. This is not a chronic use, this is NOT full scale agriculture use.

I am part owner of a blueberry farm. If we felt the need, in the USA there are imidacloprid formulations labeled for use for blueberries, should we want to do so. In the USA it is not banned, it is a widely accepted product for use. Now our blueberry farm is actually a no spray at all organic farm. We would never use imidacloprid, but we have pesticide salesmen regularly trying to sell us all manner of pesticides. Actually the Carbaryl pesticides are the ones the State of Michigan gets excited about keeping banned. Reason, too many dead farm workers, especially the poor guys who spent the day spraying the stuff, then made the mistake of having a beer anytime within 2 weeks of being exposed to the spray.

So there is a big difference in environmental impact between a bonsai grower's back yard, where one might have only 4 ounces of imidacloprid, and our farm, where we would need 300 pounds at a time to just spray the bushes once. We do not use it one the farm, because we do recognize its environmental impact. The little bit that one might use to save a special tree in ones bonsai collection, no problem. One needs to have a sense of perspective.

 

[Aeast]

Without reading this whole post and not knowing if this has been said before..

Soft scales - produce honeydew and are xylem feeders, they CAN be killed by immidicloprid or with a spray during the crawler stage.

Armored scales - do not produce honeydew and feed on individual phloem cells. These require a different systemic chemical and are harder to control. Best to spray during the crawler stage. Should be present around May-June.

 

[Mellow Mullet]

Are you sure Imidacloprid is approved/ passed for domestic use in gardens and in particular on Juniper in USA ?!!

Yes, it is readily available at any garden center.