Hm, I can't tell exactly what they are from your photos either. But I think using Sevin on those bugs would be like using a sledge hammer to kill a fly. Sevin is a chemical of last resort and I personally never use it in my garden. It's just going to nuke every bug for miles around including lots of beneficial ones.
Lin's advice to try the soapy water solution would be my first try, too. It's relatively benign but usually very effective. You should spray the plant in the evenings, maybe twice a week for the next couple of weeks to get any new hatchlings of the bugs. Hose the plant off in the morning to get the soap off the tops of the leaves.
Soap is what is known as a 'mechanical' insecticide. It kills the bugs by cutting through the protective waxy coating on their bodies. So they never get immune to it as they can to other insecticides that poison by ingestion. Just like people's infections get resistant to antibiotics, if you use it too much, or use the 'big guns' right away, resistant strains of the bugs will develop, and your problems will actually increase long-term.
If the soapy water alone doesn't cure it, try the soap/oil combination, which is better for scales because the oil literally smothers the bugs.
