Kaohsiung lychee farmers use green lights for pest control_Taiwan_News

April 14, 2025 | Taiwan News |

Kaohsiung, Taiwan’s largest producer of the jade purse lychee, is adopting green lighting at night to combat the lychee moth, a pest that damages fruit and reduces commercial value. With 2,340 hectares under cultivation and an annual output of 9,653 metric tons worth NT$1.6 billion (US$43.9 million), lychee is a major agricultural product for the city.

The Kaohsiung Department of Agriculture (DOA) commissioned National Chiayi University to research pest control strategies starting in 2021. The study found that green light at night suppresses moth activity during flowering and fruit-bearing stages, minimizing damage without relying heavily on pesticides. The larvae, which are nearly transparent and hard to detect, can spoil the fruit and deter consumers.

Replacing pesticide use with green lights could save labor costs—normally NT$4,000 (US$123) per day for two workers—and reduce the need for four to six pesticide applications annually. Damage rates dropped to under 2% with green lighting. While climate change has intensified pest breeding cycles, the technology offers an eco-friendly, cost-effective solution. The initial investment in lighting systems can be recovered within a year, and testing will expand during the upcoming May harvest season.