The fig whitefly, or Singhiella simplex, has been causing widespread damage to ficus plants throughout Florida. Although the whitefly looks small and harmless, these insects can cause incredible destruction in a short amount of time when in a large group. The ficus has no chance. Whitefly makes even the most lush ficus seemingly wither, turn yellow, drop leaves and die before your very eyes, without any explanation.
Ficus plants infested with whitefly are easy to spot as ficus hedges will begin dropping leaves, making them look unhealthy and defoliated. When the shrub is shaken, a cloud of white, tiny flies will take to the air. A closer look at the underside of the leaves will either show an egg, nymph or pupae of the fly. These will look like tiny white or silvery spots.
One form of management is the introduction of natural predators to the ficus plant to battle the whitefly infestation. Chrysoperla carnea, amitus bennetti and exochomus childreni (the ladybird beetle) are all natural predators. Local university extension services may be able to provide these specimens.
Horticultural oil can be bought from most garden centers. Horticultural oil is often used as an organic control for insects on trees and shrubs. Oil should be applied to the leaves of the ficus every seven to 10 days, late in the day to prevent the burning of foliage in the sun. Whiteflies covered in the oil are unable to move or breath, causing them to die off.
Dinotefuran is a spray pesticide that can be used to control whitefly populations. Dinotefuran should be applied to the soil around the plant. Do not use the product if there is water nearby. One application of Dinotefuran should be enough for the entire season.
Even ficus plants that have lost all their foliage may still be alive. As long as the twigs of the ficus are still moist and supple, they will likely grow back in a few weeks time. Keep the ficus well-watered as it will be stressed during the production of new foliage. Leave any fallen leaves under your plants as a mulch.