Help! Massive Juniper Scale(?) Infestation!

[TheEmpireNeverEnded]

Hello o wizened ones,

I come seeking your insight. I think I made the mistake of using Cypress bark in my cold frame this year. When I pulled this Juniper out, I was horrified to find many of the branches yellowing. Upon closer inspection, I discovered the horrific sight captured in my attached pictures. I believe this is scale, correct? I am hesitant to use a systemic pesticide, because handling such things makes me nervous. Could anyone tell me how to proceed? The tree is a San Jose Juniper. I pulled out my shimpaku and nanas, and the scale was not on them for some reason.

What can I do, kind and insightful practitioners?

Thank you

 

[Wires_Guy_wires]

Oof, that's a nasty one!
I use an oil based insecticide aimed at what I'm trying to kill, combined with neem oil emulsion.
But with infections this severe, you might want to submerge the foliage in your insecticide solution (prepared according to the label) instead of spraying.

A systemic might be better, but those aren't allowed here.

 

[TheEmpireNeverEnded]

Oof, that's a nasty one!
I use an oil based insecticide aimed at what I'm trying to kill, combined with neem oil emulsion.
But with infections this severe, you might want to submerge the foliage in your insecticide solution (prepared according to the label) instead of spraying.

A systemic might be better, but those aren't allowed here.

Thank you! Could you elaborate a bit more about what you mean when you say "submerge the foliage"? Like dip it or let it sit upside down in a bucket for a while

 

[InstilledChaos]

That is a nasty one indeed. Now is the time to do a dormant oil spray for sure. Juniper scale is an armored scale, so easily available systemics are not very effective anyways. You can use contact spray insecticides, but you have to time it right to get the crawlers, since it won’t work once they hunker down. I’d definitely quarantine that bad boy, and do a dormant oil spray on the other junipers just in case (although it will take any blue color out of the foliage unfortunately)

 

[TheEmpireNeverEnded]

Thank you! Pardon my inexperience, but what dormant oil would I be applying?

 

[sorce]

Burn it!

No way in hell the potential for more harm isn't greater than the cost of that tree.

Sorce

 

[Oleg]

If you want to keep it. Clean out all the dead and heavily yellowed and thin it out so you can spray it well. a tooth brush will dislodge the dead ones, there are a lot of dead ones there. You want to see the problem. Kaharsus is right about the timing but the time is almost here. I use Malathion at 10 day intervals, the label says it can harm Junipers but I use it on San Jose Junipers and it hasn't been a problem then I use oil "horticultural oil" just a highly refine mineral oil it suffocates them, I have heard about discoloration but it hasn't happened to mine. Maybe that's just the Neem oil. Look up the timing and you'll know when to start it's in the spring, for now use oil. My experience is you need good access to the problem and you need to stick with it. When done use the tooth brush get rid of the corpses so you know if they come back. Good luck!

 

[Wires_Guy_wires]

Thank you! Could you elaborate a bit more about what you mean when you say "submerge the foliage"? Like dip it or let it sit upside down in a bucket for a while

Let it sit upside down in a bucket for a while, you want your insecticide to get under the scales, and those seal tight. Make sure you cover the soil or dip it with container and all.
Leave it in the shade for two days afterwards.

Systemics work better because those end up in the sapflow these bugs are drinking. Spraying usually doesn't help a whole lot because of the armor of scale. It can help slowing them down.

 

[Oleg]

"Let it sit upside down in a bucket for a while, you want your insecticide to get under the scales, and those seal tight."

Thanks, I've read a lot but never heard of that, that is a lot of insecticide though! I find spraying not too bad but I spray with a pump up bottle very close and very hard on a fine mist and from every angle I can get at, maybe it is seeping under.

 

[cheap_walmart_art]

Burn it!

That's your answer for everything!

 

[Leo in N E Illinois]

I'd go "nuclear", bring in the heavy duty pesticides.

Imidacloprid is the active ingredient I would look for. Bonide makes a product with Imidacloprid, as does Bayer. It is systemic. Has a long residual activity. It should work.

 

[TheEmpireNeverEnded]

I'd go "nuclear", bring in the heavy duty pesticides.

Imidacloprid is the active ingredient I would look for. Bonide makes a product with Imidacloprid, as does Bayer. It is systemic. Has a long residual activity. It should work.

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.

 

[AJL]

Rather than nuking the tree you could leave it upside down in a bucket of washing up liquid and water overnight- that has worked for me previously on scale- infested junipers.
Is that tree really valuable and worth keeping? It looks Knackered from your photos!
Whatever you decide do isolate the tree and keep quarantined until your sure the scale is dead then treat again to kill any larvae you missed first time

 

[TheEmpireNeverEnded]

Rather than nuking the tree you could leave it upside down in a bucket of washing up liquid and water overnight- that has worked for me previously on scale- infested junipers.
Is that tree really valuable and worth keeping? It looks Knackered from your photos!
Whatever you decide do isolate the tree and keep quarantined until your sure the scale is dead then treat again to kill any larvae you missed first time

I am interested in this option. The tree is dear to me because it is one of my very favorites. it is a very young Juniper and I haven't done anything with it for the most part yet, but as part of my learning process I think I would benefit from treating this verses getting rid of the tree.

 

[TheEmpireNeverEnded]

Rather than nuking the tree you could leave it upside down in a bucket of washing up liquid and water overnight- that has worked for me previously on scale- infested junipers.
Is that tree really valuable and worth keeping? It looks Knackered from your photos!
Whatever you decide do isolate the tree and keep quarantined until your sure the scale is dead then treat again to kill any larvae you missed first time

My question is what ratio of soap to water and is any soap okay?

 

[AJL]

I used normal washing up liquid in water at double the amount you would use for handwashing your dishes- I think it was Fairy Liquid ! I wrapped the pot in shrink wrap/ cling film first to stop the soil falling out then immersed and swirled the tree about several times then left the foliage and branches submerged overnight . I repeated the treatment about 6 weeks later and it seemed to work.
Keep the tree well away from any other susceptible trees. Be aware that Minute Juniper scale insect can also possibly infest Thuja, Leylandii and Lawsons Cypress and Cryptomeria as well as Junipers so if you have any of those trees in surrounding gardens or hedges its possiblethey could be a source of re-infestation!

 

[TheEmpireNeverEnded]

I used normal washing up liquid in water at double the amount you would use for handwashing your dishes- I think it was Fairy Liquid ! I wrapped the pot in shrink wrap/ cling film first to stop the soil falling out then immersed and swirled the tree about several times then left the foliage and branches submerged overnight . I repeated the treatment about 6 weeks later and it seemed to work.
Keep the tree well away from any other susceptible trees. Be aware that Minute Juniper scale insect can also possibly infest Thuja, Leylandii and Lawsons Cypress and Cryptomeria as well as Junipers so if you have any of those trees in surrounding gardens or hedges its possiblethey could be a source of re-infestation!

Thank you this was very informative. I appreciate that you took the time to spell it out for me. I'm excited to see the results.

 

[AJL]

Youre welcome ! Washing up liquid solution is an old remedy the Agro chemical industry dont want us to know about!! - I remember my Gran used it on greenfly on her roses back in 1960s! I think it irritates the bugs, breaks down their waxey cuticle and dessicates them .

 

[Mellow Mullet]

I am with Leo on this one, a good systemic will take care of them, and prevent a re-infestation. I never will understand why people who have so much time and money tied up in their trees will not use a tried and true chemical option to rid the plant of pests that are killing it, but will try every home remedy and voodoo spell that google can come up with. There is nothing wrong with the responsible use of chemicals.

 

[InstilledChaos]

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.