Impervious insects on my Alli Ficus Tree #608458 - Ask Extension

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Impervious insects on my Alli Ficus Tree #608458

Asked December 13, 2019, 6:00 PM EST

Hello, My name is Linda Smith and I've asked about my Alii Ficus tree before, however I think the kind lady who was trying to help me thought I was a novice regarding trees and plants. All the suggestions that she gave me and the Horticulturist that used to work at the Fridley Bachmann's Garden Center has been for naught. The only thing that I did not try was a chemical that started with a D... and unfortunately , I didn't write down the name. The horticulturist that was at the Fridley Bachmann's and I never saw the actual insect on any of the leaves I brought in, she said she saw only the exoskeleton and the 'honeydew' that was left behind. I have replaced the dirt, with Bachmann's Premium Potting soil, containing no commercial fertilizer, trimmed the roots, and cleaned the pot with water only. The pot size is 20' across on top and 18" across on the bottom. I water my tree only when the meter down by her roots show a #2, then I soak until the H2O drains out. I remove the excess H2O from the drip pan. My tree stands over 5.5' tall from the top of the dirt, all total, she's 6' 10" including the pot. I've used Espoma Organic Neem Oil 3 in 1, Bonide Systemic Houseplant Insect Control, and Bonide Eight Garden & Spray Insect Control. Nothing worked. I called Malmborg's this afternoon and the gentleman I spoke with suggested a "dirt wash", and suggested I search for different types that would be right for my tree. Funny (not), I couldn't find any such thing as a 'dirt wash' for a potted inside tree. I have let my tree rest from all the chemicals to see how it would do, and it is still being attacked by this unknown & unseen insect. Just in the off-chance that the bugger is airborne, I but in my aircleaner and turned it on low. Thinking that if the insect is airborne, it will get pulled into the air cleaner and perhaps, if there is enough of dead ones, I will be able to see them ( I have professional glass frames with 5 magnifying lenses to insert into the frame for magnification) so I possibly should be able to see the buggers and then maybe identify them, God willing, I don't know what else to do!!! I live on a very limited income, so options have to stay within my budget , but will do whatever is necessary to save my tree. Within reason, of course. I try to stay within the organic products if possible, but I'll use whatever you recommend at this point to kill these insects. I will be bringing in new cats, this next week, but the room the tree is in can be closed off for whatever I have to do. It's too big and I'm to short for me to try to get a bag over it. On one of the photo's ( sorry, cheap pone, working on upgrading to better one), the white dots are actually in the veins of the leaves. This is new, I've never seen these in the leaves veins before, and I've had this tree almost 20 years now. I'm desperate to save my Alii ficus tree, but nothing is working. Please, can somebody help me??

Anoka County Minnesota

Expert Response

Hi Linda,

This is a tough situation to deal with because not only is there a lot of tree to treat, but also, not being able to see the insects bothering your tree, makes it difficult to diagnose.

In the one picture you sent with the white dots, if you rub your finger over the dots, can you sort of rub them away? I'm not able to zoom in on that picture, but it looks very much like what my orchid leaves looked like when they had a mealy bug problem.

It sounds like the insects are small. If that is the case, along with the presence of honeydew, it could be mealybugs, scale, whiteflies, or aphids. If you follow this link:  https://extension.umn.edu/product-and-houseplant-pests/insects-indoor-plants and click on the "+" sign next to the name of each of these pests, you can read additional information about them.

I don't know that I've ever heard of dirt washing before, so I'd leave that be for now.

The link above lists different chemicals that are recommended for the particular insects. Since I don't know which insect it is, the couple of things that will work are either insecticidal soap, which you can purchase at garden centers/greenhouses, or ordinary pharmacy rubbing alchohol and water, mixed in equal parts, by volume. Put the 50/50 rubbing alchohol and water mixture in a spray bottle to spray with.

For either the insecticidal soap, or rubbing alcohol and water mixture to work, you have to spray all of the leaves (and in fact, everywhere you see signs of the insects) both the top and bottom of the leaves, and you have to do it 2 times a week for 3 to 4 weeks.  The reason you have to do it for this long is because these insects are incredibly small, and are really easy to miss. Over the course of 3-4 weeks, as the insects mature, with regular spraying, you will hopefully get all of them.

Obviously, becuase your ficus tree is so big, this is a big undertaking.  If it were me doing this, I would try to cover the soil while spraying, to prevent too much of the solution getting into the dirt and causing it to be too wet.

Good luck and let me know if you have any questions.
 

Susanne Chesin Replied December 17, 2019, 11:48 PM EST
I used Eight trying to kill the little buggers. I took a tiny unused piece of ocean sponge and wiped down each leaf upper /lower, tiniest to the trunk with the Eight insecticide solution that was supposed to kill each of the insects you mentioned in your response. Didn't do a bloody thing to them.  Whatever is eating my tree is still merrily chomping away. Why would a alcohol or soapy solution work when the Eight didn't? 

The Question Asker Replied December 18, 2019, 12:01 AM EST
Hi, I’m not sure what Eight is and I don’t know why it didn’t work. It could be because it’s not one of those 4 insects bothering your tree. Without seeing the insects, I can only narrow it down based on your description, and alcohol is one of the things listed that will kill those 4 potential insects. I suggested the spray (rather than wiping it on) because, at least for me, I would be better able to saturate every nook and cranny with a spray than I would by wiping. All of the insects listed are incredibly tiny and very persistent and difficult to get rid of, that’s why I recommended the application length and frequency. I also recommended rubbing alcohol because I think in the end it may be cheaper than purchasing insecticidal soap. When you say that they are eating your tree, are you seeing areas of the leaves that are chewed up or are you referring to the honeydew residue?
Susanne Chesin Replied December 18, 2019, 12:58 AM EST
Frankly, I don't know what to call it. I don't know if the damage is the result from the insect sucking all the life out of the area of what. Also, right after the insect infestation started, all the branches and trunk went from the smooth wood grain to this mottled look. I was shocked. I asked the horticulturist (?) at Bachmanns in Fridley about it, (the previous one was excellent) didn't think it was any big deal. But I think it is, a tree that's almost 20 years old doesn't flip it's wood structure overnight for no reason....do they?  Here's another thing, I've tried to get this tree to her thicken /strengthen her trunk to no avail. I suppose get rid of the bugs first then worry about that later.
Thank you for your help. Eight is a very good chemical spray put out by BONIDE and it listed the insects you mentioned. I was told to spray every 7 days top/bottom of leaves,but NOT to cover the dirt. Interesting. I wonder if the dirt needs to be changed now since all the insecticide dripped down into the dirt?  Good grief,how much damage did I do to the roots.? 
The Question Asker Replied December 18, 2019, 10:43 AM EST
Frankly, I don't know what to call it. I don't know if the damage is the result from the insect sucking all the life out of the area of what. Also, right after the insect infestation started, all the branches and trunk went from the smooth wood grain to this mottled look. I was shocked. I asked the horticulturist (?) at Bachmanns in Fridley about it, (the previous one was excellent) didn't think it was any big deal. But I think it is, a tree that's almost 20 years old doesn't flip it's wood structure overnight for no reason....do they?  Here's another thing, I've tried to get this tree to her thicken /strengthen her trunk to no avail. I suppose get rid of the bugs first then worry about that later.
Thank you for your help. Eight is a very good chemical spray put out by BONIDE and it listed the insects you mentioned. I was told to spray every 7 days top/bottom of leaves,but NOT to cover the dirt. Interesting. I wonder if the dirt needs to be changed now since all the insecticide dripped down into the dirt?  Good grief,how much damage did I do to the roots.? 
The Question Asker Replied December 18, 2019, 10:43 AM EST
If you read the instructions on the product you are using, it will tell you if you should avoid getting the product on the soil. The only reason I mentioned covering the soil is to prevent an excessive amount of moisture - overwatering plants can cause problems too. With as big as the ficus is, saturating those leaves with whatever you decide to use is a lot of extra moisture, so to avoid potentially causing more problems, if it were me, I'd cover the soil before treatment so it didn't get wet. By watering the plant the way you described earlier, you are giving the soil a good flush, so I'm not too worried about that.
I don't know about the change in the trunk, it doesn't look abnormal from the picture for a plant of that age, and the 4 potential insects it could be are really more interested in the leaves than they are the trunk. For now, I'd concentrate on getting rid of the insects and hold off on repotting until this spring. You might also want to wipe down the outside of the pot, and any surrounding hard surfaces that are near by because some of these insects can hide on those surfaces too - https://blog-yard-garden-news.extension.umn.edu/2019/06/beyond-plant-mealy-bugs-can-hide.html

I hope you have good luck with this treatment, sometimes it's hard to get control of these insects.

Susanne Chesin Replied December 21, 2019, 11:27 AM EST

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