Rebutia flavistyla problem

[habanerocat]

These plants have been grown from seed in 2017 and were going well. Despite not being fertilized they have flowered and have shown lush growth since being re-potted this spring.

Recently though I'm noticing damage around the recessed growing point. Bad on some, getting worse on others. Red spider mite is of course suspected. However I had an outbreak last summer and it didn't look like this. Any ideas what it is and how to treat it?

[Ross M]

What time of day do you water your plants? If they were watered in the morning it could be scorch as a result of water remaining in the growing point and being magnified by the sun

[habanerocat]

What time of day do you water your plants? If they were watered in the morning it could be scorch as a result of water remaining in the growing point and being magnified by the sun

I always water in the evenings, but they do get a good splash in fairness.

[Conrad]

100%red spider mite - I have about 30 plants that were affected this way (but worse) by a RSM infestation last year.

They've all gone blind and have started growing from offsets instead.

[Ali Baba]

If it is mites you should be able to see them through a magnifying glass. Could also be thrips

[habanerocat]

I've treated all the above with Diatomaceous Earth. So we'll see how it goes.

I used a home made shaker with holes punched with a nail. The stuff I got is recommended for mites and is not food grade. It seems a bit clumpy to be honest. It's the first time I've used it.

I noticed a few days ago that a spider had crawled into the shaker and seemed to be living happily inside. He's been in there now four days. Should he not be dead by now?*

* I've since given him his freedom.

[ralphrmartin]

I tried to use this kind of product to get rid of sciara fly, with no obvious effect.

[habanerocat]

Ok so, this is how they look now. I sprayed with SB Invigorator, left a good puff of diatomaceous earth on the crown for two or more weeks, and Monday last I watered and then sprayed with neem oil solution afterwards.

I watered Monday as the forecast was for rain for the next few days. I normally do the exact opposite but read that a humid atmosphere deters the RSM. So since Monday it has been a very humid in the greenhouse, windows and door are closed. So how long dare I leave it like this as no sun due until Thursday afternoon? Very overcast and persistent rain here now.

[AndrewB]

A good systemic insecticide with RSM as a target, followed by a contact insecticide a week or two later. Then a good dose of RSM predators several weeks later is how I deal with these annoying pests.

[edds]

A good systemic insecticide with RSM as a target, followed by a contact insecticide a week or two later. Then a good dose of RSM predators several weeks later is how I deal with these annoying pests.

What systemic insecticide do you use for RSM Andrew?