JM,
No doubt about it, those are False Oleander Scale. When the scale is dead, it does not wipe off. I started getting this scale last year on my Siberian Iris. Now the scale has found my Star Magnolia. The damage is very noticable.
Someone said that spraying with the yellow mouthwash will kill them. I don't spray them, I use a cotton ball soaked with the yellow mouthwash -- just because I know that even if the wash doesn't kill them, my wiping will.

Horticultural oil is suppose to help. I don't like to use oils when the temperatures are above 75 -- so that rules me out.

Here is a link that might be useful: False Oleander Scale

Thanks so much. That looks exactly like it. I had zero luck searching.. I'm In South Florida so I guess the oil is not going to work for me too until the "winter" rolls in.
I'll try the mouthwash for sure. THANKS!

I actually cut this lemongrass down last week to about 1 ft. It was just stalks at that point, but it grew another 1 ft of blades since then and should be full again (5-6ft) soon.

I didn't cut my second lemongrass which was not really affected but I'll spot-treat with the mouthwash.

Thanks again!
-JM

Hey, thanks for this one. I have seven big bunches of lemongrass growing and have never had a problem but will save this in case I ever do. I'll cut them way back the end of Sept. or the beginning of October which I do every year. I dry the leaves and freeze the stalks - cook with the stalks and make tea and broths with the leaves. I've got more than I can eat so my friends get to share.

I think that neem oil might help with scale?

I know this is an old thread, but I would really like to know what "the yellow mouthwash" is in case I would need it for my lemongrass.

BTW, I bought some lemongrass at a local nursery and it's growing well, but doesn't look like the lemongrass I see at the Asian grocer nearby, so I bought some from them, put several of the shoots into a bucket of water outside in the shade, as it's hotter than you-know-where here and didn't want to boil it and in four days, it's started to grow roots from half of the shoots!!! I couldn't believe it when I took the shoots out of the bucket to give them fresh water. I wonder if it's because I put them in the shade of the fig tree out front? Probably not, but thanks for any information on the "yellow mouthwash".

Vivian