The ficus genus contains a variety of woody plants, many of which produce edible fig fruits, enjoyed by both humans and wildlife. Ficus trees are grown outdoors for their stately appearance and fruits, and indoors as more modest container plants. Ficus trees are susceptible to a range of both indoor and outdoor pests that should be identified and treated as soon as possible.
The diaprepes root weevil, the Cuban laurel thrip, spider mites and mealybugs are all common pests of the ficus tree. Aphids may also be an issue for new, young trees. Weevils and thrips are dark-colored, large insects, while spider mites and aphids are quite tiny and travel in groups. Mealybugs, which commonly afflict indoor ficus plants like the fiddle-leaf fig (Ficus lyrata), are a grayish or white and often have a thin, hair-like tail.
Root weevils feed on ficus foliage, causing unsightly "notching" damage on ficus leaves. This kind of damage is similar in appearance to the damage done by caterpillars, so try to identify the bug before you treat the tree. The larvae, which feed on roots in the soil, contribute to the overall decline of the ficus tree's health. Cuban laurel thrips cause purplish brown spots on the foliage of a variety of ficus trees, particularly the Cuban laurel ficus (Ficus retusa).
Root weevils have proven difficult to treat, especially when their larvae has made it into the soil. Insecticidal root drenches, which allow chemicals to go deep into the ground, are sometimes effective. Cuban laurel thrips attack new foliage, and it may be easier to carefully trim away new foliage than to directly remove or kill the bugs. Once deprived of their food source, thrips will often move on or die out. Washing house plants with a direct jet of water is often all it takes to dislodge spider mites and mealybugs.
The simplest way to prevent insect infestations is to keep the tree in good health, although you may also want to consider growing a more pest-resistant species. Always follow the care requirements for your particular ficus species to keep the tree healthy and strong. Most ficus species prefer moist, well draining, rich soils. A tree that's suffering from drought or over-watering is more likely to "catch" an insect infestation.
Insecticides contain harsh chemicals that can be hard on the environment and hard on humans. When treating ficus houseplants, take care to apply insecticides outdoors or in a well ventilated area. Always follow instructions, and keep the original insecticide container so you have access to poison control and dosage information. Avoid handling insects with your bare hands, as thrips in particular may nip when dislodged from a tree.