An effective way to remove termites from a living tree safely is to inject the tree with orange oil. Drill holes into the infested wood, and inject orange oil directly into the hollow spaces. Most termites die within a few days from direct contact, but many also succumb to orange oil's residual effects, which can last up to three weeks after application.
Orange oil is marketed as a natural, less toxic alternative to traditional, chemical-laden insecticides; however, it is not to be confused with orange juice. It is a highly potent extract from orange peels that is insoluble in water and causes gastrointestinal upset if ingested. It is a highly concentrated extract that can cause severe allergic reactions and skin irritation if handled improperly.
The active ingredient in orange oil is called D-Limonene, a chemical that is also effective against ants, flies, mites, crickets and mosquitoes. The oil works by physically dissolving the termite's outer skeleton, causing the insect to dehydrate and lose protein without its protective covering. Orange oil also deters termites from feeding, so any insects that do not die from direct contact eventually die from starvation. After treatment, periodically check the formerly infested area for signs of termites, and reapply orange oil as needed.
Termites eat dry wood, so if termites are found on a living tree, something else is causing the destruction of the wood. Determining the cause can help save the tree.