Natural Pest Management: Hawaii's Biocontrol Success

Cottony cushionCottony Cushion Scale. https://biocontrol.ucr.edu/cottony-cushion-scale cushion scale

If you are managing an organic operation, you already know that dealing with pests is a daily challenge. Finding effective, safe ways to protect your crops without relying on broad-spectrum chemicals can feel like an uphill battle, especially here in Hawai'i where there is twelve months of pest pressure. But what if you could enlist a microscopic army to do the heavy lifting for you?

That is exactly what classical biocontrol offers. By introducing natural enemies to manage pest populations, you can protect your yield while maintaining your organic certification. It is a cornerstone of regenerative agriculture, allowing you to work alongside nature rather than fighting against it.

This three-part guide provides tailored organic agricultural insights for your farm. We will explore the fascinating history of biocontrols in Hawaii, detail specific natural enemies for common crop pests, and show you exactly which covercrops and insectary plants you can grow to attract these beneficial allies.

Part 1: Introduction to Classical Biocontrols in Hawaii

Classical biological control involves intentionally introducing natural enemies—like predators, parasites, or pathogens—to control an invasive pest population. Think of it as bringing in a specialized task force to restore balance to your farm's ecosystem.

Hawaii has a long and successful track record with this practice. The first recorded release of a biocontrol agent in the state occurred in 1902, when insects and diseases were brought from Mexico to control invasive lantana. Since then, the Hawaiian government has safely practiced biological control to manage devastating agricultural and ecological threats. Between 1890 and 1985 alone, over 240 natural enemies were introduced to target roughly 200 pest species.

A Legacy of Success

Erythrina Gall Wasp. https://arborjet.com/problems-solutions/insects-and-mites/erythrina-gall-wasp/

When a pest arrives in Hawaii without its natural predators, populations can explode. A perfect example was the Erythrina gall wasp, discovered on Oahu in 2005. It spread rapidly, decimating native Wiliwili trees. In 2008, after rigorous testing, scientists released a tiny parasitic wasp (Eurytoma erythrinae) from Africa. The results were remarkably fast, and the Wiliwili tree population made an incredible comeback.

Another major victory occurred with the giant whitefly. Discovered in Hawaii in 2002, this pest severely damaged hibiscus and plumeria. Within a year, a tiny parasitic wasp (Idioporus affinis) that had fortuitously arrived with the pest began attacking the whiteflies. Today, the

Idioporus affinis. https://en.wikipedia.org/wiki/Idioporus

giant whitefly is scarce across the islands, controlled entirely by this natural enemy.

These historical successes prove that biological control is a highly effective, low-cost solution for long-term pest management.

FMI:

Department of Land and Natural Resources (DLNR). (2013). Erythrina Gall Wasp Advisory. https://dlnr.hawaii.gov/ecosystems/files/2013/07/Erythrina-Gall-Wasp-Advisory-HDOA.pdf

Hawaiʻi Department of Agriculture (HDOA). (2007). Papaya Mealybug - New Pest Advisory. https://dab.hawaii.gov/pi/files/2013/01/npa04-03-PMB.pdf

University of Hawaiʻi (UH). (n.d.). Biological Control of Lantana, Prickly Pear, and Hamakua Pamakani in Hawaii: A Review and Update. https://www2.hawaii.edu/~theodore/Images/biocontrol_weeds_hawaii.pdf

Vargas, R. I., Leblanc, L., Harris, E. J., & Manoukis, N. C. (2012). Regional Suppression of Bactrocera Fruit Flies (Diptera: Tephritidae) in the Pacific through Biological Control and Prospects for Future Introductions into Other Areas of the World. Insects, 3(3), 727–742. https://doi.org/10.3390/insects3030727 Cited by: 139