What kind of pest or disease it is?

Mealybug Click on above green link so that you can get detail information along with control measures in Plantix library. Syed Ansar Ghani

Thank you for your reply. I had mealybug on my hibiscus but that looked different (although white in color). I thought it is something different than mealybugs.

It may be scale insect. Pls send some other images pls Syed Ansar Ghani

Hi Syed Ansar Ghani as per your images the symtoms are much close to the attack of citrus wolly aphid. 1. First of all remove such infested fruits or leaves and buried them into soil. 2. go for the application of imidachloprid powder to get rid of them. I hope you will get better results. For your reference I'm attaching an image.