Sticky Leaves on a Ficus Tree

Aphids

• Aphids are 1/16- to 1/8-inch-long, soft-bodied insects that are usually green, but may also be yellow, black, brown or pink. As aphids feed on ficus foliage, they excrete a sticky honeydew substance onto surrounding foliage and stems. Aphid damage leads to wilted, yellowed and distorted foliage that often falls prematurely. Control aphids by washing the leaves off with a strong spray of water or by wiping the foliage with a soft cloth. If the latter control methods prove ineffective, treat aphids by dabbing them with a swab dipped in rubbing alcohol or by spraying with insecticidal soap. Repeat as necessary.

Mealybugs

• Mealybugs are 1/8- to 1/4-inch-long white, cotton-like insects that pierce ficus tree leaves and stems to ingest plant sap. The feeding leads to honeydew excretion on the ficus and stunted and distorted growth. Mealybugs are commonly found on the underside of leaves and where the leaf meets the stem. Control this pest, which has a waxy protective outer coating, by dabbing mealybugs with rubbing-alcohol-soaked cotton swabs, spraying with insecticidal soap or by applying the appropriate pesticide. Biological controls such as the mealybug destroyer ladybird beetle Cryptolaemus montrouzeri are also effective.

Scale Insects

• Scale insects are bump-like brown or black insects ranging in size from 1/16 to 1/2 inch in diameter. This pest tends to congregate on stems and the underside of leaves. Scale insects suck ficus tree sap and excrete honeydew. Their feeding weakens plants and causes leaf loss. Many scale insects possess hard, armor-like shells that shield them from insecticides. Remove small scale infestations with your fingernail or by rubbing the pest off with a soft cloth. When the problem is extensive, treat scale insects with horticultural oil spray.

Whiteflies

• Not true flies, whiteflies are 1/10- to 1/16-inch-long mothlike insects covered in a white, powdery coating. They tend to flutter around ficus when the foliage is disturbed. Whiteflies suck plant sap and excrete honeydew, weakening ficus and causing premature leaf loss. Trap flying whiteflies on yellow sticky cards or vacuum the pests from the air. Destroy whitefly on foliage by applying horticultural oil, neem insecticide or insecticidal soap.