white sticky stuff on the leaves of my citrus

snailkillerAugust 16, 2012


I am a newbie here and I have a question. I live in Houston,Tx and I have a grapefuit tree and a meyer lemon tree in my backyard. Both trees have this really sticky, thick white stuff on the underside of the leaves. I tried to find out what it is and found cottony scale, but I don't think that is it. There are no bugs on the leaves just thick white sticky stuff. It has now started to turn some leaves darker than others on the grapefruit tree, and spreading to the fruit.

I have sprayed it with GardenSafe Fungacide 3,but it is still there. I'm including a photo. Can anyone here tell me what this nasty stuff is and ow to treat it organically?

I do not want to lose my trees. ;(

Thank you

Thank you for reporting this comment. Undo
rhizo_1 (North AL) zone 7

Rule #1 regarding pest control...especially organic control....is to identify the problem BEFORE you spray.

I believe that this is a very bad infestation of wooley aphids, probably Citrus Wooley aphids. They produce copious amounts of sticky sugary excrement upon which a simple black mold grows. The sticky stuff is called 'honey dew '; the black stuff is called 'black sooty mold '.

Whatever you end up using on your plants, even if plain water, you will have to direct the applications to the underside of the leaves....that's where these guys are hanging out.

    Bookmark   August 16, 2012 at 12:15PM
Thank you for reporting this comment. Undo

For a garden plant I would just wash them off with a sponge, water, and maybe a little dish soap. The bigger problem for citrus is if you don't control the ants you WILL get aphids. It is almost always true that when you see aphids on citrus you have an ant problem. No ants, aphids are rarely a problem.
I agree with rhizo, they look like wooly aphids.

    Bookmark   August 16, 2012 at 2:38PM
Thank you for reporting this comment. Undo

Thank you,
JOhnmerr and Rhizo 1 for your replies.
I have never had this problem before. The grapefruit tree is 8 years old and the lemon tree is 2 years old.
Can these "wooly aphids" kill our trees?
I will look up how to treat unless you have suggestions. The grapefruit tree is way too big for me to sponge off with water and soap. It's about 15 ft. tall
Ants have been very bad herein Texas this year due to the drought last year and the past warm winter then lots of rain in the early part of the year.
Geeez...ants have been everywhere. I have been treating them with orange oil and molasses.
Should I prune back some of the branch's to allow more airflow or is that not an issue?

Thank you again ;)

    Bookmark   August 16, 2012 at 4:16PM
Sign Up to comment
More Discussions
Meyer Lemon tree question
I have a 3-4yr old meyer lemon tree i've kept in a...
Thomasville Citrangequat Zone 6b SUCCESS
Just wanted to let everyone know that my Thomasville...
Costco citrus!
Has your Costco started to stock any? We got some kumquat,...
Grapefruit Tree fertilizer
Hi everyone. I have a question regarding fertilizer...
Help with citrus scale
Hello all, my satsuma mandarin is dropping leaves....
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™