A Problem? Need Assistance, Please

I noticed these spots/pits/discolorations on my H. cv 'Jennifer' last week. The condition is not present on all the leaves and appears different on some of the leaves. The most severely effected seem to be toward the top of the plant. Would an unusually cold environment cause this? Or, might it be a condition due to a weakening of the plant from the cold? The reason I ask this is that it has been in the low 20s and high teens this past week and my house (rental) is very hard to heat. I use electric space heaters and don't trust them enough to leave them running in an unoccupied room during the night, so the room where my plants live sometimes gets into the 30s.
I will post several pictures I just took. Any help you can give me would be very much appreciated. I really don't want to lose this plant, because if I had to pick my favorite one, it would be this one!
Thanks!!!!

Barb

Another...

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I have the same problem with H. coriacea but much worse. My splotches on my leaves are becoming larger and more yellow. Seems like I should be able to find critters on it, but I don't see any.

No clue and I am concerned.

Mine seems to be affecting the newer leaves rather than the entire plant.

Hi Susan. This has me totally perplexed. I've researched every website I can find but am unable to locate anything close to what the plant is showing. I took it out of the pot last night and examined as much of the root system as I could but nothing looked unusual. Then I took a magnifying glass to see if there were any critters lurking and found none. The leaves are rigid, as is the norm for this plant. So... I am left scratching my chin wondering what is going on with my favorite Hoya. Also, I took a couple of cuttings to root for someone else and don't want to pass along a disease, if indeed one is present.
I hope someone can give us an idea what it is..

Barb

I've had symptoms like this on a zonal geranium, it turned out to be edema. (see the Garden Terms) http://davesgarden.com/terms/go/1850.html

Do hoya get this?

Gee, where's Carol when we need her?

Aloha oi??????
Hei, hvor er De?

LOL no doubt about it, I'm better with my Norwegian sayings than Hawaiian! LOL :~D

Have you used any sprays?

A L O H A!!! Remember....I am 5 hours behind the E. Coast......2 hrs. behind CA.

Those marks on cv. Jennifer look more like popped pustules, right? They aren't just 'spots' that some hoyas get from sun, right?

It could be a fungus....Cercosphora is very common and it makes little spots like blisters on the back side and sometimes they turn yellow around the spots. It is a favorite of H. obscura and cv. Sunrise.. You could try the home remedies like Tinactin in an aerosol can... but I would rather use a specific fungicide....Detol works...just look at the label. Be sure to spray the whole plant...tops and bottom.....

Hope this helps....

Carol

Thanks for pointing me in the right direction, Carol. I will pick up Detol as soon as I can get to the store. (This being without a vehicle is inconvenient in the extreme!!)
Linda, I haven't used any sprays yet because I tend to try to find the critter or disease that is causing the problem and treat that rather than use a blanket pesticide or treatment in hopes that it will cure whatever ails the plant.
I learned this the hard way one year when I first started gardening and saw caterpillars on a plant.. rushed right over and sprayed the heck out of them and the plant thinking they were invaders and were out to destroy my precious garden! Well ~ after the fact ~ I found out they were the larvae of the very butterfly I had grown the plant to attract. Taught me a good lesson and I'm a bit more cautious now.
I will let you know how the treatment goes.
Thanks for the assist, you guys. :~)

Barb

That stuff I recommended might be called Detrol...something like that. Red Spray bottle. It does leave a film on the leaves which flakes off.

Gotcha.. thanks!

:~)