I have a small hoya collection and have noticed some strange leaf damage and spotting on several plants. On my Hoya carnosa, new leaves are often streaked and contorted. (See pics 1-3). They also have small marks on them.
The other problem is on my Hoya wayetii. This one has white specs on several leaves, the fourth pic is of one of the worst.
There are no mealybugs and no signs of spider mite. All leaves are firm and there is no sign of rot or mush. The plants are fairly close to a double T5 lamp, though I haven't read of any problems for these varieties close to light. I let them get dry-ish before I water, they have individual thirsty lights.
I can't find anything that matches. Maybe scale for the wayetii, or thrips damage on the carnosa? These are the closest guesses I have.
I have been watching this thread with great interest because I sometimes see some contorting with my Kentiana - I tend to keep my hoyas a bit on the dry side and I am wondering if this contributes to the contorting. Thoughts?
You might have something there.
It is possible mine dry out too much between watering.
Mine seems to be only on the new growth and then appears to outgrow it.
Is yours on new growth only? And do your Kentiana leaves outgrow it?
The flecks seem more common on the newer leaves, less on the older so that suggests they may out grow it a bit. But there's not much in the way of contorting on the plants. However, I've seen contorting on H. australis ssp rupicola, without any apparent cause nor any apparent ill effect. My H. pubicalyx has that streaking/marbling on the leaves which seems to be natural. Healthy leaves/plants and it's all over them.
The contorting does seem to be on the newer leaves and I don't see anything on the older leaves, so they must normalize as they grow. I know there is a redness on the leaves as well that I think is also due to the plant being on the dry side. On the flip side, the plant has been a blooming machines, so I don't think the plant is doing too badly.
The only streaking I am seeing is on my H. pubicalyx as well.