How far can scale travel?

[jay]

I have just found some scale on the flowers of my new Dendrobium Karen. I don't see any on the leaves though.

My question is how far can the scale travel to a new area. This Den. was about 10-15 feet away from all of my other orchids. I have moved it farther away, but do I need to worry about my other orchids getting infested?

And just to clarify, is scale the little fuzzy things that look like an anthropod? I was so angry at them I didn't wait to take a photo, just picked them off with tweezers.


Jay

[Tobi]

Hi Jay,
Scale insects appear as hard-shelled elliptical brownish-white bumps attached
to leaves and stems. They can be on the flowers and pseudobulbs as well.
From your description, it could be Mealybugs. These are oval, cottony insects
with hairy protrusions which could be your description of fuzzy. Use a cotton
swab dipped in 70 percent denatured alcohol to remove either one and keep
an eye on the plant. If you see more, than you'll have to use an insecticial
soap or horticultural oil weekly for several weeks.

[11Orchid126]

I don't know how far they can travel, but you can carry them from plant to plant unknowingly. If not treated, the whole collection can get infested almost overnight. It also sounds to me like mealy's and not scale. Scale stay in one place and are not fuzzy. If they were my plants, I'd treat the whole collection just to be on the safe side.

[WIB]

I agree that it sounds like mealybugs, not scale (having had a rampant mealybug infestation in my collection a couple of years ago). I wound up having to use acephate, which is marketed in garden centers as Ortho Systemic Insect killer. In the basement I set up a large cardboard box that I then covered with a plastic bag, so as to confine the spray. (Acephate is supposed to be used only outdoors. It is relatively nontoxic, except to sucking insects. It rapidly degrades in the environment, and residues should disappear over the course of two or three weeks. It is used on crops.) For the orchids I found that I had to make it up at two or three times the recommended concentration, but the plants all tolerated it just fine. Plants need to be sprayed three times, at intervals of a week to ten days to get the juvenile stages as they mature. Once I got the concentration high enough, it worked very well, and I have not seen mealybugs on the sprayed plants since then. I have seen one or two that were easily disposed of with an alcohol swab. I don't feel too awful about the environment, as the residue is confined to the carboard box, and the material decomposes to generally nontoxic materials in a relatively short time. No outdoor, wild creatures, such as honeybees, were exposed to it. If it had not been such a persistent infestation, I would have tried to stick with alcohol, which orchids also seem to tolerate very well, even when it is sprayed on them.

[tizzycat]

Scale Insect???

Hi Jay, that doesn't sound like scale, see the thread above for a picture and some advice.

Good luck.

[Cynthia, Prescott, AZ]

Mealies, yes, but to answer the question for others, the early life of scale is mobile, so they probably can move around as much as mealies.

[jay]

Ok, so I probably have mealybugs.

Are they the ones that leave the little fuzzy cobweb like stuff in the joints of the flowers?

So now I wonder how far can these little ******* travel?

I have picked off as much as possible with tweezers. The plant is in S/H so there is not an organic media for them to live in. Will this help?

Jay

[Miki]

Hi Jay,
I don't know how far they can travel, but they can sure move fast!

I found mealies on my phals the other day. I picked them off and left them on the table to show my kids, and with in a flash, they were gone!!!! Little buggers!

I have controlled the mealies on my s/h phals by an organic spray (similar to neem), because their little white eggs are just too small to be picked off by hand!

So, I say 'spray' if you are in doubt!

[pikevi]

jay: if you are concerned with the 'speed of its spread' I would not worry too much about it. I am NOT speaking with authority or experience here but many infected (with mealy bugs) I purchased seem very localised. One or two applications of either neem or safer's soap had had eliminated them within a day or two.

There is a possible 'carrier' aspect of its spread. We may inadvertently carry it from an infected plant to a healthy plant via our hands or tools used.

As Miki said neem seems to be very effective even on healthy plants as a preventive measure.

During and following the applications I keep them under semi-quarantine for a couple of days to a week just to confirm that the bugs are really gone.

Good luck.

[Cynthia, Prescott, AZ]

Don't use neem for mealies. Neem has some down sides, not to mention that you have to have 100% coverage, which is going to mean a lot of the mixture, as the mealies have been known to live inside open mixes like bark and S/H and live on the roots. It will be much better for you to use a systemic like Bayer Advanced Rose & Flower, the ready mixed stuff, or the B. A. Tree & Shrub, which you will have to figure out how much to use to give you the same concentration of imidacloprid that is in the Rose and Flower. OK, I see I have 2 Tablespoons per gal in my records. Use a couple of treatments a week or so apart, just to be sure you are rid of the mealies completely.

Neem can cause mottled foliage. I don't know why, but I have been operating on the assumption that it lowers the defense of the plant against fungal infection, so I have been using systemic fungicides with it. So far I haven't seen any mottled foliage, but I will need more time to ascertain if this is really working to prevent mottling. The neem should be reserved for mites which systemics don't work on.