White, Dusty Splotches on leaves?

[Mothman]

Hello...I'm relatively new to orchids and I have a question about my Phalenopsis orchid. I've noticed that the leaves on my orchid are developing these white, dusty splotches or patches. And no, its not just dust collecting on the leaves.

I'm wondering if this is a bad sign or not. Does this mean that the orchid is not getting enough light? too much light? etc?

thanks!

[mayres]

Are we talking the upper side or under side (or both) of the leaves. Can you take a digital photo closeup? The thing that comes to mind is mealy bugs - which is usually heaviest on the under side. If this is definately not the issue, can you give us some more information about lighting, watering, etc. conditions that you have your plant?

[Mothman]

The white splotches are on the top side of the leaves.
I water once a week usually...am using the bamboo skewer method.
Its planted in spag moss.
Light is a medium/strong constant next to a South facing window.

I havent checked the underside for bugs but I will when I get home. Will try to get a pic up too.

thanks..

[Cynthia, Prescott, AZ]

Does it look like hardwater residue, like water spots on your glass ware? Cynthia

[poeteye]

Mealy love phalies! Spray with a strong solution of undiluted rubbing alcohol and wipe clean with a paper towel. The alcohol will kill the bugs, but evaporate before it harms the leaves. Killing them, however is not enough -- the little buggers lay eggs on their own bodies and baby bugs can spring from the corpses. You must thoroughly clean the leaves. If, when you get home, you find more fuzzies on the leaves undersides (I suspect it may be worse below) you may want to think about repotting to prevent recurrence.

[Mothman]

yes it looks like hardwater residue..but its not water. I checked and dont see any bugs...

hmm...will work on the pic..

[damage]

I got three Phalaenopsies and one a them purple ones that looks like a Vanda but has a Phalaenopsis 'mouthpiece'... the purpley one definitely has those mealy bugs. Here in the UK we don't see much of those so first of all I thought they were spiders, then woodlice :-(

I sprayed them with warm soapy water, which is an old British tradition that doesn't cure anything at all but at least it makes you feel useful, after which I identified them from looking at the names for various pests here then looking them up on Google images (saves you the time of uploading a photo and waiting for a reply).

Two of my others haven't shown any signs of the Weapons of Plant Destruction, but I assume they will. So, Neem oil it is then,unless any UK viewers got better ideas?

The white stuff may also be fertilizer residue. You might try rubbing the leaf gently with lemon juice, milk, or mayonnaise which are used as leaf shine to see if it disappears.

[mayres]

If you continue to go the al la natural method - be diligent! If you don't stay after them every few days you can turn you head for a moment and lo and behold those little creepy crawlies are all over the place again. Personally I have come to rely on a ready to use spray bottle of ortho or bayer rose and flower systemic insecticide - works well and has staying power of 30 days. Good luck. mike

[Mothman]

Ok..I've taken a closer look and these white splotches have gotten worse...the tops of the green leaves now have this scarred, pitted look. Like someone was scraping the green out of it..the white splotches are actually the inside layers of the leaf after the green has been scraped out. It looks like someone sprayed acid on the leaves. I still see no evidence of bugs on the underside of the leaf.

What is going on here?

thanks!

[Cynthia, Prescott, AZ]

It could be mites. They are all extremey small, with some even smaller. The only time I have ever seen them without a microscope, is when spider mites have made some super fine webs, and I can see dust on a web that slowly moves. Those were mites. So, don't worry about seeing them, base you conclusions on the symptoms. So, mites are chlorophyll eaters. Look for any of these symptoms, you may only see one or two.

A silvery look to the leaves.
A whitish look, sometimes along the edges, that have a sandy pattern.
Sap oozing out of the leaves over an area, not just a dew drop here and there which may be normal.
A lot of scared tissue (hard to describe).
Red tinge on white tissue after rubbing underside of leaves (red mites only).
The presence of superfine webs (sometimes you can see dust that moves on it), misting helps to make the webs visable.

If you suspect mites, I would spray the plants, all of them very thoroughly with neem oil, then keep the plants in a cool (<75F), low light place for a couple of days (very important). Since you can't see these guys, it is important that you use some thing that works well, as you can't just wait and see if the material worked, and most pesticides do not kill mites. You might also give the plants another spraying a couple of weeks later, as a bad infestation might result in a bug being missed. Cynthia

[atcrosby]

Neem Oil is the best for mites. Be sure to follow the directions and keep the plants out of the sun for a few days. It's like putting suntan lotion on your skin, it'll burn the leaves much much faster.

Neem is a good natural insecticide and it won't hurt people or the environment. My research shows it's been around for ages and is used in organic farming.

Good luck.

[Mothman]

Cynthia, Atcrosby..
thanks for the advice.

My orchid leaves show extensive signs of scarring and pittting. I dont see any webs or silver tinge but I guess maybe the mites are too small to see.

Could it be something else other than mites?

Also..where do I find Neem oil?

thanks again!

[Cynthia, Prescott, AZ]

Most nurseries have neem oil. Give them a call on the phone. Sometimes I see it at home centers. There is a ready mix that has pyrethrin or a variation of it that is a little hard on some of the more delicate orchids and particularly on flowers. The concentrate can usually be found without this undesired additive. There may be other insects but I have not had any of them be a problem yet, so I can't comment. Neem is one of the broadest use pesticides, so it make work on whatever your plant is suffering from. Cynthia

[Mothman]

thanks Cynthia..

2 of the leaves on my phal turned leathery and fell off. The underside was brown but the top had white scars/pits/splotches.

I managed to obtain some neem oil spray...its made by some company called Green something...and was at Home Depot. Its supposed to function as a fungicide, mitecide, and general pesticide.

The product contains 0.9% Clarified hydrogrophic Neem Oil.

Is this strong enough to use on mites? The label says its a "mitecide". Also..theres no mention about keeping the plant out of bright light even though the main ingredient is Neem Oil. I assume I should still keep the plant in a shady area..


Also..the directions say treat for 7-14 days. Does this mean that I should spray everyday for 14 days?

thanks

[damage]

Two of the leaves on one of my newer plants are turning a bright yellow, and underneath they have a couple of patches that look a little like faint red scabs marked with silver...

on the other one with the mealy bugs, although they seem to be kept a bit under control by the soapy water, one of the main leaves is now kind of red down the middle with yellowing to the outside and black pslits in it. is it the mealy boys doing that, or have i got to worry about something else now?

[Cynthia, Prescott, AZ]

It is very difficult to tell without pictures, and then it still may be wrongly diagnosed. I would say that neem oil is the broadest and most effective product I have used. I would do the second treatment in a week or two, just to be sure you have gotten all of what ever your plant is suffering from. When I use it in my green house, and do a very thorough job, there has been so much of the chemical deposited from the over spray (spray one plant, and everything else gets a second dusting, that I think the bugs that aren't killed have no recourse but to live for a very short time in this VERY toxic environment. I just bought one of the Hudson Foggers that will put out a very fine mist. I expect with this, that there will be no over spray, and a second treatment will be necessary, but I am hoping that the fogger will use so much less spray that the machine will pay for itself in short order. Also, the over spray leaves so much oil on the plants, that some of the thin leaved plants seem to be stressed by the oil. Definitely keep the plants in a cool, low light place for a couple of days, or you will have blotchy looking leaves from photo/phytotoxic damage. It was very interesting to see this damage and a shadow line where there was a perfectly normal section on a leaf where it had been covered by another leaf. Cynthia

[Mothman]

thanks for the info Cythina...

I'm still not sure if its mites or not but i sprayed the neem oil on it. It looks like the damage isnt getting any worse but all the leaves now are kinda leathery looking.

I'm debating if i should repot it into a bigger pot and check the roots. Maybe the roots are rotten or there are bugs underneath?

you havn't mentioned other conditions, air movement, humidity? is the plant getting too much sun? the distance from a south window is important. you might detect spider mite using an old technique: place a white paper under the leaf then tap the leaf vigorously if you see any specks then that is the problem. no need to repot a blooming sized phal into a larger pot, just repot into the same sized pot with new medium. phals like new medium every year or so. just a warning ... you can love them too much and the results of fiddling is the plant can go south rapidly.

[Cynthia, Prescott, AZ]

Yes, don't go bigger if you don't have to. Use the smallest pot you can get all the roots into. Sometimes this is a bigger pot because you need a deeper pot to be able to get all the roots covered. I would bring the mix up to the highest root, and no higher, or lower if there is a leaf that will be burried above where the leaf turns downward. Don't worry about the look of the leaves, they will be replace in due course. Cynthia