What is the cause and fix?
Sticky Leaves on Indoor Bird of Paridise
The stickiness is called honeydew and it is secreted by both mealybugs and scale insects. Mealybugs look like bits of white cotton. Scale insects appears as slightly raised brown bumps on the leaves.
The treatment for both is the same. Mix a solution of 5 parts water, 1 part alcohol and a squirt of liquid dish soap. Then, spray the entire plant - all of the leaf and stem surfaces - until they are literally dripping wet. Thoroughness is the key to success because if you miss even a few of the nearly invisible juveniles, they will mature, reproduce, and come back to haunt you later. It is a messy chore, but one treatment is usually effective if you are really thorough.
Be sure that the spray gets down deep into the crevices where the leaf stems attach to the main stem.
Pests are often an indicator that the plant is under stress for other reasons. Make sure your B of P is close to a sunny window and that the soil is kept moist at all times. Healthy plants are much more resistant to plant pests.