Ariel have you had very hot days if you have its more likely the direct sun. when DR get over heated they do this strange thing .:×)

Drought response.

I guess I’ll water more. Thanks!

Highs in the upper 20s - low 30s C (mid-80s F) mostly, but in winter it doesn’t rain. I’m still getting the hang of planting in Lechuza Pon

This is a bug doing this to the leaves. Look close you can see a pattern on the leaves.

Another thought ... If I get fertilizer on the leaves and don't rinse it off, this happens once the hot sun hits them.

In case it might be a bug, I’ll segregate the maybe 3 or 4 plants from the other hundred or so that don't appear affected yet.

Yes, better to control early, before spreading, if it's a bug.

Thank you for bringing this very important point up, Peter.

We must all take note that one size does not fit all in the adenium world. While all adeniums like some direct sunlight, not all can tolerate constant direct [high lumen] sunlight ... But some can! The intensity of the sun differs from region to region, so what works in one area may not work in another. Some plants are more sensitive than others and it appears to be genetic to the specific plant.

I have all my plants together [under scalding Equator sun] and notice that the same ones consistently show signs of sun stress, evidenced by crispy brown or blanched leaves. I have allowed them to 'suffer' this year to see whether they outgrow this tendency ... They haven't. Come Spring 2018, I will move the more sensitive ones to morning only sun.