They're pretty!

Having said that, you did the right thing just plucking out the big ones. There might still be eggs or tiny ones in your plants so you do still need to spray them with something.

Did you get some kind of systemic chemical pesticide? If so, put that aside for now.

Instead, get a gallon of water, add a teaspoon of dish soap and a teaspoon of oil. Then shake vigorously. You can use that as spray before resorting to systemic pesticide (which is what I'm assuming you got). Spray your plants at sundown so they spend the next hours out of the sun. The following day at sun-up, you can hose them down to rinse off the soap and oil. Then I suggest spraying them thoroughly again with the solution at sundown. It works by literally smothering the caterpillars. There's really no need for chemical warfare. Save that for the really horrible creatures.

After a week, repeat.

Here's the good news. Now you know you have a local population of whatever that leaf-eater is. You can prepare for next time it happens. I suggest you research neem oil so next time you can use that instead.

Or you can continue making the solution I described above. Both will work. Some people add other things to the soap solution like Rosemary tea or garlic. I just personally prefer neem oil because it works on many more pests through both smothering and absorption. But before I got neem oil, I used the solution I suggested and it worked well for moths, aphids, and various leafhoppers.

The reason I am discouraging the use of systemic pesticide is this: insects and arachnids develop resistance to pesticides very quickly. But none of them will ever develop resistance to smothering and drowning without first turning into fish. So, better save the big guns for the more difficult infestations and use only when all else have failed.

For adeniums, specifically, the bigger concern are flowers. We grow these plants for the flowers. Certain pesticides (like imidacloprid) are secreted in the nectar of flowers which are then taken up by pollinators like bees and kills them. So you'll want to avoid that.

Thank you so much Pagan. I will mix the solution tonight and spray my plants tonight. I am so thankful to you. I was so worried. Thanks

My all 100 seedlings suffered similar fate when i came back from vacation...no leaves and tops also chewed off.....i caught and threw away the large fat caterpillars....and now 1 mo later, lost some that couldnot recover,...and most have started branching quite well.....they look good...so donot throw away any...wait and watch...they might recover....drenching them with any chemica at that point harms more than helps is what i experienced....

Thank you, Shimolee. I am hoping they will grow new leaves.

If & when you buy Neem Oil, buy a concentrate 70%-100% pure. Don't buy the "Ready To Use" (RTU) which comes in a spray bottle, it's mostly water.