Citrus Plant Sticky Leaves

13 years ago

Hi,

My indoor lime and orange tree's have both had sticky leaves for a number of months. If i take them outside and hose the leaves the problem goes away for a week or so.

There are some 'things' on some of the leaves that are possibly the cause but I don't know what they are or how to treat them. I've taken a photo but it looks like there is no way to post onto this forum. Can anyone help?

Cheers,

Andy

Featured Answer

don_in_ct

13 years ago

last modified: 9 years ago

Yep. That is Brown Scale, or Brown Soft Scale, or Soft Brown Scale, a very common scale insect. The tan insects that are visible are the older ones, and the almost transparent insects are usually males, but they can just be immature females. All of the ones I can see in the pictures have already settled down and won't move on their own: they have settled in to suck the juices out of the leaves and stems. Eventually, as they age, the females will turn a dark brown color and be more rounded: that is about the time they give birth to little baby scale insects.

Not visible in your pictures, but possibly present, are the little tiny ones, which are still mobile. (If you only had a single breeding female scale on one tree to begin with, the scale insects you see may be the only ones). If the little crawlers are present, they will move to a spot they like, and then settle down and do what the adults do.

Normally, scale insects don't cause much of a problem when you put healthy citrus trees outside for the summer, since the outdoor environment is not conducive to their spreading, but if you put trees with an infestation outside you are possibly going to have a problem. Indoors, because of the dry air and steady temperatures, a few scale insects can very quickly become a serious problem. Left unchecked, they can weaken and eventually kill a tree.

My preferred method of control is two-fold if the plant is small enough and the infestation is not too overwhelming. First, I like to rub the little buggers out with my finger or a pencil point. In particular, I look for any particularly large and rounded scale, since these are the ones that are going to produce the nymphs (they may already be under the large adult).

Disturbing the adult insects doesn't take much pressure. It may not be necessary, but the insects have a waxy coating, and I think it probably makes it easier for the next step to work. I don't rub the scale insects before the second dose.

The second step: spray with a horticultural oil spray twice, at an interval of about 7 to 10 days. Another way to go would be to use something like Neem oil extract, but I have not tried that. The Horticultural Oil route is nice because it is easy to mix up a quart of the solution, spray the tree or trees, let them drip dry, and then bring them back inside. The brand I picked up at the local nursery has no odor and can be used up to the day of harvest. I'd say that most of them on the market are the same, so I wouldn't worry too much about that.

So, I would spray the trees twice, 7 to 10 days apart, and the problem should go away for the summer. Make sure you spray the tops and bottoms of all the leaves, and the branches and trunk. Make sure the trees aren't in need of water before you spray them. If they are, water them, and wait a day before spraying.

Then, in the fall, I would spray twice again shortly before they come back inside.

Even with this regime, it is still possible that they will show up again around December-March, since it really only takes one of them to start another infestation. I've sprayed some of my trees each winter (usually just once) at some point or other when I see the insects. This year they showed up on three of my trees. I just pick a warmish day (temperatures above freezing, sunny, no wind), spray them, and then put them on the unheated porch to drip dry. They are only outside for 10 to 15 minutes, tops. The goal in this case is not to eliminate all the insects, but to reduce their numbers enough that the problem is insignificant for the rest of the indoor season.

Comments (12)

rhizo_1 (North AL) zone 7
13 years ago
last modified: 9 years ago
Andy, lots and lots of people post images to the forums. ;-) But if you like, you can email me your pictures, and I'll have a look-see.

So, tell us....do these 'things' move around or are they more like odd bumps that seem glued to the leaves, but that can be scraped off with your finger nail? Or, do they look like something else entirely. Without an image, we need more than 'things' to go by. ;-)

I will say this with some certainty: the sticky stuff is the excrement of a sucking insect of some kind. Scale insects, whitefly, aphids, mealybugs, and others suck plant sap 24/7, filtering it so that they keep the good stuff inside and excrete sugary water.

Knowing the identity of your pest is important in being able to control it.
don_in_ct
13 years ago
last modified: 9 years ago
I second rhizo's list. From your description, my money is on scale. If you google "citrus scale" you will find plenty of pictures to compare your situation to. Even if you have scale, since there a quite a few types of scale insects that infect citrus, you may have to browse around to find an exact match. Basically, the adults look like little limpets that are attached like suction cups usually to the green stems or leaves.

To post pics to this forum, you have to first post them to an on-line service like Flickr which will host them. Then you copy the link and paste it into the same window you compose your message in (and not the Optional Link URL or Name of the Link boxes). It is a bit tricky at first!

{{gwi:569665}}
Related Discussions
New to citrus normal leaves have fallen off all my citrus
Q
Comments (4)
Where are you located? Must be somewhere near me. I'm in Alachua County and we had some crazy temperature swings here in late Feb and early March. One of my trees has also lost its leaves and I was thinking the temp. swings could have been a factor, though some here say it could be root rot. Citrus doesn't like temp. fluctuations. Did you have the wild swings from 80 to freezing and back over a few days?
...See More
Problems with my Citrus Plants, Scale, Crinkly Leaves and Die Off
Q
Comments (18)
Hey Toni, thanks for your complements on my plants. Beleive it or not, all of my plants with the exception of the Aussie FIngerlime have been grown from seed. As a matter of fact, the Grapefruits were personally selected and liberated by me :) . I was out in AZ at the end of 2001, I was out for a evening drive with my wife and sister in law, we went to the highest point in Phoenix, then on the way back I passed a former manson with a radio station billboard on it with some sort of event going on at the grounds. It had a semi circular driveway and the entire very large front lawn was fileld with quite old Grapefruit trees, all seemingly the same type. When I went 3/4 of the way around I stoped said what the hell, jumped out looked at a nice looking tree and picked 2 grapefruits off the tree, the biggest and best ones I could find, and tossed them into the car. I had to wait 1.5 months for the box for some reason to come back to NY that I shipped em in but they were intact and whole. I had the seeds of one of the grapefruits planted for me by a friend and co-worker, since he had better facilities and room for that. Once they gre we split up the bunch. I kept 3 seedling and the other 2 went with him. I think he has one tree left. The other 3 have been growing with me ever since. Grapefruits #1 & 2 were so close together that I decided no to seperate them, they seem sto be doing great otherwise so it has never been a worry. The Key Limes were a bit simpler. Basically I bought a bag of "Susie" Key Limes in 2004, made a key Lime pie, saved the seeds, 15 seedlings grew. I lost 10 of them when I went away for 5 days and the pot they were in was not watered while I was gone. I planted the remainnig 5. One died in a month, another died suddenly of mysterious leaf loss the next year. Now of course I had a Key Lime almost die of the same mystery. The Lemon was planted September of 2005. I palnted 6 seeds,only 1 came up. I thought I had a second plant but it turned out initally to look like a weed. I figured I would let the weed keep the lemon company for a while. I was almost ready to pull the weed and then it flowered, then about a month later I found a whole bunch of small thai peppers growing on it...lol. It was a seedling for when I planted some in the same pot 2 years previous. As you can tell I just stuck the seed in existing dirt. The Kumquat I bought at the local Stop and Shop in December of 2005 and got 2 seedlings from that. I will be transplanting them soon. The Aussie FIngerlime I bought from a place in South Carolina. I will be looking up the name of the place when I get to work tomorrow. Anyway that is my story, so no grafts except on the Aussie, all is from seed. VTY -Mark
...See More
Help! Indian Laurels dropping leaves, sticky leaves, curled
Q
Comments (1)
The first step is to identify the pest, but in most cases, you'll find Bayer Advanced 3-in-1 Insect Disease & Mite Control will handily take care of any insects that feed on sap. You'll want the concentrate. In addition to the systemic insecticide (Imidacloprid), it also has a miticide (forget the name) and a systemic fungicide (Tebuconazole). Al
...See More
Black dots on leaves and stem of my citrus plant
Q
Comments (7)
Thanks for the responses. Yes, they do spread to the branches and I noticed that these dots are a lot easier to remove when they are on branches. The leaves are naturally variegated and has nothing to do with the black dots. No it is not a recent addition. This plant has been there for about a year and I started to notice the black spots maybe 1 month ago and they multiplied quite rapidly. My location is in the Philippines. This plant is directly planted onto the garden beside other plants. Surprisingly the three plants beside it do not have these spots. The infected one is a local citrus plant we call "calamansi" (scientific name: Citrus xmicrocarpa). I have a couple more citrus plants in the garden, an american lemon, another variety of the "calamansi" and a few others. Luckily they are not beside this infected plant and are healthy and do not show signs of the pest. If they are Citrus Scale, what is the best way to control them?
...See More
AndyN
Original Author
13 years ago
last modified: 9 years ago
Thanks for the responses! I've uploaded two pics of one leaf so that you can see both sides.

http://www.flickr.com/photos/61967240@N04/5636628617/in/photostream

http://www.flickr.com/photos/61967240@N04/5636630541/in/photostream

What pest(s) do I have and what should I treat with pls?

Here is a link that might be useful: Pic 1
anthonyenright1
6 years ago
It is Scale insect. It took me hours to find this out and I used neem oil spray first then i took a soft tooth brush with mild dish soap and worked the insects off the stems.The main reason I believe that the sap is on the leaves and on the floor is the Trees instinct to save itself by attracting Ants to it so the Ants can eat the larvae and Insect.
usmcgnr
6 years ago
I have this same problem and want to try one of the sprays but my orange is planted in the floor of my green house. Did you only talk about moving the plant out doors to avoid a mess or will there be a problem getting the spray on the dirt floor or other plants?
anthonyenright1
6 years ago
If you have a Greenhouse then I would order a container of Ladybugs and let them eat your problem.
usmcgnr
6 years ago
Did that already. Turned 1500 loose two weeks ago in my greenhouse (36' X 26'. Two days later I started finding them dead on the leaves of the orange. I suspect the cause maybe some leftover insecticidal soap reside on the orange leaves which didn't seem to affect the scale. Sticky residue on the leaves is getting worse.
Vladimir (Zone 5b Massachusetts)
6 years ago
Spray with neem oil.
anthonyenright1
6 years ago
OK Marine I was a Navy Submarine Cook and I trained and cooked for you guys in the field.So either you are going to have to treat it with a Systematic Pesticide or your going to have to make their living conditions hell by changing to the opposite of what they are doing now. I have even seen using baking soda and water spray to change the Ph but you are getting close back off on the pesticides try to go natural a lot of times it is something stupid like a malnutrition of the tree that makes it weak.
usmcgnr
6 years ago
Thanks to both of you. Went to Lowes yesterday and they didn't stock any product labeled as need oil and only one product labeled as a horticultural oil but it contained mineral oil as its primary. After some more reading, I Like the idea of need oil and intend to try it next along with some genial leaf scrubbing. Thanks again.
usmcgnr
6 years ago
I actually rode on a sub once, USS Greyback. In the early 70s someone wanted to see what and how long it would take to minimally train a standard Marine rifle company to lock out and back in a sub for a raid. They only cheated a bit. They formed a rifle company with 1st class and WSSIs swimmer but no one scuba trained. Messed around a bit at Coronado training then sailed to Hawaii with some more training enroute and under way. Final exercise was a raid in the Pahocos Training area. Followed up with two day group drunk out while the heavies debriefed. Slept nearly all the way back to Coronado. Great food not a fan of hot racking.

Citrus Plant Sticky Leaves

don_in_ct

Comments (12)

rhizo_1 (North AL) zone 7

don_in_ct

Related Discussions

AndyN
Original Author

anthonyenright1

usmcgnr

anthonyenright1

usmcgnr

Vladimir (Zone 5b Massachusetts)

anthonyenright1

usmcgnr

usmcgnr

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Citrus Plant Sticky Leaves

Comments (12)

Related Discussions

AndyNOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

AndyN
Original Author