white sticky stuff on the leaves of my citrus

12 years ago

Hello,

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

Featured Answer

rhizo_1 (North AL) zone 7

12 years ago

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.

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Comments (10)

johnmerr
12 years ago
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.
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snailkiller
Original Author
12 years ago
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 ;)
garrettkondo
8 years ago
I have the exact same problem and have not yet discovered anyone who is sure of what this problem is. My tree is still small so i shot with a power garden hose the underside of the infested leaves. Will update in a few days.
garrettkondo
8 years ago
After research the first guy is correct wooley aphids. Use dish soap 1 tbl spoon to a quart of water. Or you can buy a insecticidal soap.
0
Yanuario Arias
2 years ago
this is not wooly amphids, if it were you'd see living creatures at some point, i've seen none i've had this problem for years, treated whit almost everything, going to try a systemic fungicide now.
0
Citrange UK
2 years ago
This is a whitefly infestation - probably Wooly Whitefly, Aleurothrixus floccosus, although some other species look similar. The white deposits eventually become black with mould but it's no use trying to control with fungicides - you have to get rid of the whiteflies. Not easy without using nasty chemicals.
Christopher Stevens
2 years ago
Try neem oil. I have the same issue and I'm going to try this natural, safe solution. Good luck!
100Redbuii
7 months ago
Did the Neem oil work I have 3 grapefruit trees in Bolivia have the same issue
0
Silica
7 months ago
YOU can use either neem or horticultural oil sprays,, both work on mealy bugs very well.

white sticky stuff on the leaves of my citrus

rhizo_1 (North AL) zone 7

Comments (10)

johnmerr

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snailkiller
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white sticky stuff on the leaves of my citrus

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