Mealybugs

Your plant’s problem may be mealybugs; insects with a sticky, cottony covering, but we recommend you confirm by using a magnifying lens to examine this, or take an affected leaf (sealed in a bag) to your local garden center for confirmation. We’ve also included a link so you can see what to look for. Mealybugs suck the nutrients out of the plant, excreting the sugary sap. Wipe these off with a cotton swab moistened in alcohol and water, or use a pesticidal soap or neem oil product if you see tiny ones on the stem where the leaves are attached. Continue to monitor for return of the organism and clean-it off if found. Follow directions on all product labels to avoid damage to the plant – more is NOT better!
http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/INVERT/mealybugs.html