Using orange oil for termites can be a better solution for pest control than other toxic solutions, such as tent fumigation.
What is Orange Oil?
Even though orange oil smells strongly of citrus, it is not a fruit juice but is instead an extract from orange peels, a substance that is insoluble in water. It is used for pest control as well as general cleaning and you can buy orange oil and readily formulated orange oil pesticides at home improvement stores.
Although orange peel shavings can be used to flavor foods and a small dose of the oil from the orange peel is said to convey health benefits, large amounts of the oil can cause vomiting and nausea in humans. Such negative effects are even greater when the orange oil is used against insect pests. Orange oil can be deadly to many insects, including cockroaches, ants, dust mites, flies, wasps, spiders, crickets, and, perhaps most importantly, termites.
Orange Oil as a Termiticide
Orange oil as a natural product is increasingly marketed as a herbicide and insecticide, with particular effectiveness for killing dry wood termites. (Dry wood termites thrive on a building's hard, dry wood.) So, what is this wonder product and how does it kill termites?
The active ingredient of orange oil is d-limonene, a chemical known to be both a weed killer and an effective insecticide against a variety of pests, including flies, mosquitoes, ants, crickets, and mites. Scientists say that the oil dissolves the termite's exoskeleton, which destroys the insect's cell membranes and kills the bug due to massive losses of water and protein.
How to Apply Orange Oil for Termites
Once a dry wood termite colony has been found, the mode of treatment is to drill holes into the infested wood and inject the orange oil into the hollow spaces where the termites are feeding. The treatment works best if the insect galleries are identified and treated. Studies show that some residual effects continue in varying degrees from three days to three weeks after direct injection.
The majority of termites are killed by direct contact, and since orange oil deters the termites from feeding, some of them will then starve. After the treatment, the home or business owner should periodically check for signs of a new infestation. Trained termite-sniffing dogs have been very effective in sniffing out new or previously undetected termite colonies. Orange oil treatment is typically not preventative but must be applied each time a new infestation is discovered.
Pros and Cons of Orange Oil Termite Treatment
Though orange oil is appealing for use in battling insects, it's not a do-all, end-all panacea against termites. Along with its benefits, it has several drawbacks.
- It's less toxic than arsenic and modern chemicals such as fipronil, imidacloprid, and hexaflumuron.
- Orange oil can kill insects on direct contact and cause others to starve to death.
- Orange oil is a no-tent treatment. It does not require that humans, pets, or plants vacate the premises for treatment.
- Orange oil is not completely safe since it can cause stomach upset if ingested and irritation to the skin.
- Some sources debate orange oil's efficacy against termites. For example, the Agriculture and Natural Resources, University of California states, "There are many localized [drywood termite] treatment methods available that include both chemical and nonchemical options....Botanical-based products (e.g., orange oil and neem oil) have been tried, but recent lab and field tests from two universities question the efficacy of at least d-limonene."
- While orange oil does seem to kill termites on contact, its residual effectiveness is minimal so it may not permanently get rid of termites. Repeated applications are the norm when using orange oil.
- Termite galleries must be located and drilled into so the oil can be injected. Commercial fumigation, on the other hand, can kill termites throughout the house. The boreholes used to inject the oil can also leave a substantial amount of patching to be done.
Orange Oil vs. Fumigation
Using orange oil may be better than using a fumigation treatment for your household for a few reasons. A fumigation treatment requires extensive and costly preparation to rid your home of termites. That's because your home will need to be tented for the fumigating treatment to work.
Fumigation also requires that humans, pets, or plants leave the premises for treatment, and all food will usually need to be removed, too. It's much less expensive to buy orange oil for a DIY treatment or ask a pest control company to use orange oil than it is to have fumigation, though the tented treatment will be far more effective.
The Bottom Line
As a minimally toxic pesticide, orange oil is worth trying as a solution against dry wood termites. But expect a somewhat lower level of effectiveness when compared to other commercial pesticides and pest control services, and be prepared for repeated applications as new infestations occur.
"Material Safety Data Sheet - Orange Oil." Northwest Missouri State University.
Raina, Ashok, et al. Effect of Orange Oil Extract on the Formosan Subterranean Termite (Isoptera: Rhinotermitidae). Journal of Economic Entomology, vol. 100, no. 3, 2007, pp. 880–885., doi:10.1093/jee/100.3.880
Hong, Young-Seoub et al. Health effects of chronic arsenic exposure. Journal of preventive medicine and public health & Yebang Uihakhoe chi vol. 47,5 (2014): 245-52. doi:10.3961/jpmph.14.035
"Drywood Termites." Agriculture and Natural Resources, University of California.