Pest? Disease? IDK
 

Hi Guys,

I've had this issue with my favorite denphal since it started putting out new growth for me. The past 3 growths have these silvery pitted markings on the tops and bottoms of each leaf. New growths are also quick to drop leaves. No visible pests have been noticed in this time period. Do me a favor and check out attached photos to see if you recognize these markings. Neighboring plants have not had this issue.

Thank you,
Gillian

That looks like spider mite damage.

I agree, that looks like typical spider mite damage. If you don't see any mites or their webs, then there's a high chance that the culprit is false spider mites (also called flat mites). They are microscopic in size (can't easily be seen with the naked eye) and don't make webs.

If only the one plant is affected, you can rub both sides of all the leaves with rubbing alcohol, it's usually quite effective. You will probably need to repeat this treatment a few times, every couple weeks. If the problem has spread to other plants, then chemical treatment may be needed.

Also thrips can cause that damage. You'll never see them with the naked eye. (Flower thrips are larger and visible.) I use Azamax 3x at weekly intervals. When I can, I also use a systemic in the potting media.