Suspiciously mealy-looking bug

[Paul]

Whatever other treatment(s) you decide to use, ABSOLUTELY discard all the old media and rinse off the plant and roots before repotting. If using the same pot, sterilize the pot first in a 10% bleach solution and then wash/rinse it well to remove any bleach residue.

[rbarata]

Maybe you'd like to read my thread here.

It was with a dendrobium but I guess the treatment can be the same.

[estación seca]

Originally Posted by rbarata

Maybe you'd like to read my thread ....

Yes, I read that. The treatment could be the same.

[Skycat]

Threw away the pot and media yesterday, and washed the plant with water and alcohol. And then today I washed with water/alcohol again. Still unpotted.

Also I just noticed today that the alcohol I have is 91% instead of the 70% that people usually recommend.

Here's what the plant looks like



That was today, right before I washed it. Not sure if the white bits were baby mealies or mold; it did kind of spend the night in a plastic grocery bag.

I wasn't sure about the roots, because they're dark brown, but they're still firm and solid, and as I'm gathering from Google, apparently it's normal for Paphs to have brown roots? So maybe the rhizome isn't as dead as it looks?

[bil]

I repot everything I buy straight away. I keep the old bark tho and let it dry right out, then I use it for ferns.

When I do get bugs that are a problem, like thrips, I spray with confidor, two doses two weeks apart. Confidor is a systematic but it aso kills on contact. You could also let it wash thru the medium prior to repotting if you wanted.

TBH there's a case to be made for treating every new plant as if it is diseased.

[rbarata]

Also I just noticed today that the alcohol I have is 91% instead of the 70% that people usually recommend.

What is often mentioned here as Isopropyl alcohol is something not common in my country and not easy to find. I also never used it when trying to get rid of mealy bugs.
But there's no problem, use a smaller concentration.
You used 90% alcohol instead of 70%. So dilute in the same amout of water 20% less alcohol (90-70%=20%).

[buffalo]

When it comes to mealy bug best to declare war on them and be consistent going out to battle. I fight them with alcohol and i find a mixture of neem oil , dish washing soap and water to be very effective if you are dealing alot of them. I check plants for them often.
Best to check for them before you bring the plants home.

[lepetitmartien]

If you want to to make 70° alcohol from a 91% base, you have to add 31% of water ( according to the Gay-Lussac tables of dilution).

That is for 100 ml of 91° alcohol, add 31 ml of water.

[Orchid Whisperer]

Easy way to calculate the dilution, for any concentration, to make any volume you want.

Equation is: C1 x V1 = C2 x V2

C1 and C2 are concentrations, C1 is the concentration you start with, C2 is the concentration you want.
Let's say C1 = 91% and C2 = 70%

V1 and V2 are starting (V1) and ending (V2) volumes.

If you want 50 ml of 70% alcohol, just re-arrange the equation and solve.

C1 x V1 = C2 x V2 Put in your numbers:
0.91 x V1 = 0.70 x 50
Re-arrange:
(0.70 x 50) / 0.91 = V1 = 38.5 ml

So, mix 38.5 ml of 91% alcohol with distilled water to make 50 ml (= add 11.5 ml) and you should have 50 ml of 70% alcohol.