You have a scale infestation. Probably best to treat with with a horticultural oil that is listed as effective on scale. It will probably be labeled "Summer", "Perfect", or "All-Season" Horticultural Oil. Making sure to follow directions explicitly and cover all surfaces of leaves & stems with special attention paid to undersides of leaves and all the nooks & crannies.

Al

You may wish to share with us what kind of plant this is....just in case. Some are sensitive to horticultural oils...not many but enough to be a little bit cautious.

Be sure to check your other plants carefully, too.

Thanks for the advice tapla. Will give it a try:)

Rhizo - I'm not sure what kind of plant it is. I'm newer at this sort of thing. Can you tell from the photo?

It's a schefflera, and hort oil is appropriate for that plant if you'd like to try it. Read the label before you buy & before you use .... as with all insecticidal products. To help avoid any problems with over-watering, you should allow your plant to become quite dry before you soak the soil thoroughly - then repeat.

Al

Thanks so much for the suggestions. I'll give it a shot