Myrtus communis compacta scale

[Mikea454]

I found one of these buggers on my new set of dwarf myrtles (trunk middle and top of photo). I scraped it off and crushed it immediately.

Most importantly do I need to treat them systemically if I can't see any more on any tree?

I think its a barnacle scale from what I can tell. sorry the picture is a little fuzzy. I've seen black soot being a symptom of some scale, could the white on the leaves be similar, or unrelated mold (I've only sprayed with horticultural soap)

 

[Mikea454]

shots of trunks of the two trees that look the most "feeble". Not sure I see anything but what I think is bark

 

[Esolin]

You can try to beat scale by diligently watching and scraping it off. You might be successful on such small specimens. Horitculural oils I understand can smother some scale types, but you need to be careful what times a year to apply oils, as they can burn trees in the height of summer. Your myrtles already look like they've have a bit of heat or chemical damage (I see some curled, dry leaves on branch ends). Systemics are a pretty sure fire way to get rid of scale, provided the right type and dose are used, but I'd suggest waiting and watching. You just got these trees. Let them acclimatize to their new home before you start fumigating them. If they were mine, I'd just watch and pick off any visible scale for now and treat with oils or systemics in the Spring when the trees are better able to handle treatment.

 

[Michigan Tree Murderer]

Sounds like you're on point removing and disposing of them. They may have laid eggs so check it periodically. To be safe you could spray with an insecticidal soap to kill scale and the eggs, not sure about the black soot issue maybe someone else is. Good luck.

 

[Shibui]

Sooty mould lives on the sweet honeydew that scale produce. It is always black so the white on the leaves is not sooty mould.
Phone pictures are not clear enough to say what it is definitely but could be juvenile scale? Could be hard water deposits? Could be a few others too.
There also appears to be white on the soil which can be hard water or mould growing on the organics in the soil mix - usually related to the soil being too wet for too long.

Treat scale with either horticultural oils (newer formulae are safer to use on plants than some of the original versions) or systemics.
A couple of scale is not an invasion or is it fatal to trees so just checking regularly will be enough for now, especially now that you are on guard and know what to look for. Treat if and when you have a problem.

 

[Mikea454]

thanks guys, I wasn't sure if this was one of those things that for every 1 you see there are tons you don't (ie younger stages to small to see clearly) yes they did seem to suffer some heat damage in the triplet of 95 degree days we had two weeks ago (surprisingly they came from California, near LA, I wouldn't have thought massachusetts much hotter)

I'll keep watching. I have them all still quarantined and moved them back to shade when I saw the leaf curl.

 

[penumbra]

Damage looks environmental, as in drying or some other issue. I love dwarf myrtle, but they can suffer drastically from missing a watering. I have a few and lost one a couple years back that was quite a beauty from drying out too much. Also, it is one of the few plants that I have to use a systemic on or they will get mealy bugs. .

 

[Esolin]

Damage looks environmental, as in drying or some other issue. I love dwarf myrtle, but they can suffer drastically from missing a watering. I have a few and lost one a couple years back that was quite a beauty from drying out too much. Also, it is one of the few plants that I have to use a systemic on or they will get mealy bugs. .

I'll second this. I had some myrtles in small pots once, and one missed day of watering in the summer was the death of them.

 

[Mikea454]

I'll second this. I had some myrtles in small pots once, and one missed day of watering in the summer was the death of them.

thanks for the warnings

 

[Mikea454]

the ones from earlier this year are happy and blooming as they had time to adjust to the heat, and not 60 to 90 overnight