I was checking my 9 yr old plant (my first curry leaf), and realized that grey fluffy things are on the sprigs and also top of the growing points. There were glossy honey dew similar to that of scale insects and aphids.
I was not sure what could be the key words to search. Anyhow, I googled with Japanese words meaning “fluffy” and “aphid”. There they are!
It is called “Shivaphis celti” (academic name). Often called Woolly Aphid.
I recall seeng them on my Pandan plant, but first time on the curry leaf plant. It secretes wax material to make the fluffy woolly thing. It sucks juice from the plant which is as bad as other aphids. Some of them have wings so that just brushing them off will not be permanent care. I just crushed them with my fingers as much as possible.