7

We live in Southwest Florida. About a month ago, or maybe a little longer, I trimmed back our hibiscus plants. Today, I just noticed this mass of white, almost powdery, substance on the branches and leaves of one of the plants.

What is this, and more importantly, what can I do about it?

Hibiscus with white substance

Sue Saddest Farewell TGO GL
  • 6,215
  • 8
  • 39
  • 74
unkfrank
  • 639
  • 1
  • 4
  • 9
  • [Mealybugs](http://en.m.wikipedia.org/wiki/Mealybug). Let me check, I'm sure we have a few posts on these... – Stephie May 28 '15 at 20:46
  • 1
    Found it! [here](http://gardening.stackexchange.com/questions/4564/orange-tree-has-pest-or-blight) – Stephie May 28 '15 at 20:57
  • Yup. Mealybug spray with soap and water – kevinskio May 28 '15 at 22:52
  • You guys should post as an answer to get this whole thread more attention. Definitely looks like wooly aphids. – That Idiot May 29 '15 at 01:28
  • @ThatIdiot : AFAIK we are supposed *not* to answer if we recognize a duplicate, but VTC. Did I get something wrong? (Not that I would resent possible rep gain, but the [help center](http://gardening.stackexchange.com/help/how-to-answer) clearly says so.) – Stephie May 29 '15 at 06:07
  • I'm not convinced this is a duplicate. Yes, it's the same pest, but it is a different host and looks quite a bit different. I think someone looking for help might not recognize the infestation shown in the other photo. And I know I've seen more than one post on aphids. Cross referencing would be important, but unless there are many such hibiscus infestation questions I'd argue this deserves its own answer. – That Idiot May 29 '15 at 09:11
  • FWIW, I did some research on mealy bugs and wooly aphids (since I hadn't experienced either), and based on comparing different views of both, it looks like mealybugs. The wooly aphid look more hairy (for lack of a better term) in the images that I found compared to what I have (and my camera phone doesn't do the best closeup photos). I don't know enough to say if this is a duplicate (same pest, different plant, but I searched for something like 'white on hibiscus'), but if Stephie adds an answer, I'll happily accept that. Much appreciate the help, guess I'll be busy for a bit ;-) – unkfrank May 29 '15 at 11:29

1 Answers1

7

This is most likely to be a cottony mealybug.

  • You can control this taking a paper towel soaked in dish soap and water and wiping the leaves down.
  • Repeat for every leaf with the symptoms. Check the axils where the leaves join the stems too.
  • After the treatment rinse or spray with water to prevent a soapy buildup
  • repeat every five to seven days for at least three times
  • continue to monitor as mealybug is hard to get rid of
  • move the tree away from any other houseplants. Some adult mealybugs have wings and fly to spread the population.
  • check for other plants that may have it too

Mealybugs can be difficult to control as the white "cotton" prevents most control agents from reaching them. More details on their control are here. It is critical to spray the plant with soap and water or neem oil at least three times.

Mealybugs are found on many plants but common hosts are citrus, hibiscus, ficus, crotons, aglonema and many other temperate climate plants.

kevinskio
  • 57,927
  • 9
  • 76
  • 157