Pest Damage Giant whitefly is causing serious damage to many ornamental plant species found in nurseries, landscape gardens, and home gardens. The plant species most affected by the giant whitefly are hibiscus, giant bird of paradise, orchid tree, banana, mulberry, xylosma, and aralia. Certain varieties of citrus and avocado are also being affected. Whiteflies cause two types of damage to plants. The first is direct damage.
Direct damage is caused by the loss of plant sap.
Both nymphal and adult whiteflies feed by inserting their needle-like mouth parts into the vascular tissues or phloem of the leaves and suck out the plant sap. If the numbers of whiteflies per leaf are great enough, the plant will suffer from lack of water and nutrients, resulting in a weakened plant, loss of leaves, and possible plant death. The second kind of damage caused by whiteflies is indirect damage. During the feeding process, whiteflies excrete a sticky, sugary solution called honeydew. This sticky honeydew accumulates on the leaves and fosters the growth of a black sooty mold fungus.