What could this be?

[ILS]

Hello,

I'm new on this site but wanted to stop in and see if I could get some help. I'm a bit lost as what could be happening with my orchid. I've only had orchids for about 8 months but never had any problems now all of a sudden I have two orchids not doing so well? I feel awful and would love to get them back to health.

One of the orchids started getting black specs on the leaves and black edges on the leaves. That was about a week ago and now the whole bottom of the leaves are white/silver. What could be causing this?

The other orchid (both dendrobiums) has the leaves turning yellow. It does not look like sunburn to me but to be honest I really dont have any experience.

Thank you in advance. Any suggestions appreciated

Orchid 1


http://i23.photobucket.com/albums/b3...idresized2.jpg

Orchid 2

[Lagoon]

Hi ILS, welcome aboard

The first one looks like it has spider mites. The second looks like its not getting the right minerals ...

Tell us more about your growing conditions - where in the states are you?

[ILS]

I live in south florida. I keep my orchids in our screened in patio. I'm watering my orchids every other sunday with a fertilizer I bought at home depot. I use it every watering and then on the fourth watering I use a bloom booster they sold me at home depot as well. I basically follow the instructions on the bags

How do I get rid of spider mites? I'm going to google it and see what I can find. Can it spread to my other orchids?

Thank you very much for your response.

[Tindomul]

I agree, it looks like mites. You will have to start by cleaning the leaves. You can go and find neem oil and soap and water to further clean the leaves and keep pests away. I would change the potting soil/substrate as well.

[camille1585]

Yup, I'd say spider mites too. At first I was thinking about thrips since they cause silvering as well, but since there is so much of it, I think mites now. Thrips would leave much much smaller silver spots.
I also agree with the course of action Tin suggests. That's probably what I would do if I had mites (and hope I never do!)
As for the second one, I have no clue what it is. I don't think it looks to good.

[ILS]

Thank you for your input I'm off to buy the neem oil and repotting supplies. Should I look for the leaves improving in color and appearance with the treatment or simply a reduction in the spreading?

On the second plant I'm going to repot it in a new medium and hope for the best. I'm not sure if to continue the regular watering schedule or add more fertiziler or not? I hate to see the leaves getting sooo yellow. I checked the roots and they look fine. I have it in a shady with late sun area?

Thank you once again. You are all soo very helpful!

[Lorraine]

Looks like spider mites to me too. You can get Organicide at home Depot also. I use it about once a month add a little palmolive dishwasher soap to make it stick on the plant. There are so many bugs that love our plants down here. Mealy bugs find their way quickly too.

Wash off your plant really well with soapy water then pot it up again and give it a good spray with insecticide. I keep a Quart bottle make up and spray as needed also..
Lorraine

[camille1585]

On second thought, it could be thrips, even though I still think it could be spider mites. Have a look at this:
banded greenhouse thrips damage on dendrobium
It's an example of extreme damage, but pretty similar!

At work I study a different type of thrips, which does not silver the leaves as much. I also work with bell pepper, not orchids. If it is thrips, they will be hard to see, just like the spider mites. They are less than 2mm long.
In both cases I don't think treating will make the damage go away, it will just stop it from speading.

[isurus79]

That second plant (the dend with yellowing leaves) looks like its getting burnt, either with too much light or too much fertilizer. I cant tell if that smaller growth is actually growing, but I do know that a lot of dends are dormant this time of year. If you are fertilizing it and it is not in active growth, you might actually end up killing the plant. You also dont mention how strong your fert regimine is.

[Des]

Thats red spider mite for sure the ozzies call them two spotted mite. They always seem two appear when the humidity is low These bugs are so small you cannot see them with the naked eye ( well I can't). Mineral oil spays will kill them . Prevention is better than cure though , so remember to watch for them next year and spray every 10 to 14 days . Make sure you spray under the leaves as this is where they live