Cuban Ficus Thrips have been attacking these trees for several years now. The new growth is curled with small white and black insects inside. Since the leaves are curled the thrips can be hard to kill with contact insecticides. Neem Oil, Spinosad and Pyrethrins are organic recommendations to help control. If possible I would also trim off the new growth where the leaves are curled and discard the bugs first before attempting a spray. A systemic liquid or granule applied into the root system may be a more effective way to control these pests. Bonide Systemic Granules work great in pots applied every 6-8 weeks. For larger trees planted in the ground, Bayer Tree and Shrub Protect and Feed applied as a soil drench around the base of the tree may be an easier option applied every 9 months to a year. Regular watering of your ficus will keep it healthy and allows the plant to withstand and outgrow thrip damage. Excessive, fast release or improper nitrogen fertilizer application can stimulate a flush of tender new growth particularly attractive to thrips. These insects will not kill your trees, they just make them unattractive with leaf droppage.