Photograph would be good - you haven't said which ficus either, indoor or outdoor, fruiting or foliage. If its outdoor, could be scale, and possibly mealybug, we don't get mealybug on outdoor plants so much, only on indoor, but I guess you might over there. But a photo of the problem would be good to say for sure.

thanks ....ficus is outdoors and non fruiting

Hi Flack - see my answer under your newly posted question.

Firstly let me say, welcome to GoY.

Your problem might possibly be Woolly Aphids (Erisoma lanigerum)
They also excrete honeydew which coats the leaves and Sooty Mould may start to grow.

Treatments.
The colonies can be rubbed away with a brush and soapy water.
A forceful jet of water will remove the bulk of a colony.
Use a cloth soaked in metholated spirit to 'brush' them off.
A spray prepared from a couple drops of washing-up liquid to a gallon of water as an acceptable organic method of control; so are insecticidal soaps made from plant fatty acids. Avoid spraying in sunshine to prevent scorching the plant.
Encourage birds such as Blue Tits to the area by supplying feeders and nest boxes.
Place Ladybird and Lacewing shelters nearby to provide winter quarters for them. These can be specially made structures or bunches of dried, hollow stems tied together and placed horizontally in a sheltered spot.
Daisy-like yellow flowers attract insects such as Hoverflies and Lacewings and their larvae feed on aphids.
Biological controls need a constant supply to survive, so there will always be a low-level presence, hopefully these will be on nearby wild plants. Ladybirds (ladybugs) are nocturnal so if they are feeding during the day the number of aphids may be low.
An acceptable organic spray is made from an extract of the Neem tree called Azadiractin
For chemical control use *imidacloprid, pyrethroids or bifenthrin - spray as late in the day as possible to avoid Ladybirds and other friendly creatures. Follow directions and precautions given on packs, especially if treating fruit trees.
*Are a known source of CCB (colony colapse in bees).
source
http://www.dgsgardening.btinternet.co.uk/woollyaphid.htm

I hope this helps. If it didn't at least it gave you something to read.
Isn't the internet wonderful! ;-))