Single Ramie Moth Caterpillar Confirmed on Kauaʻi; Officials Urge Reporting

A single live ramie moth caterpillar, the first confirmed detection of the invasive ramie moth on Kauaʻi, was reported to the Kauaʻi Invasive Species Committee and collected for laboratory identification. The find, reported Jan. 26, 2026, has officials from the DLNR Division of Forestry and Wildlife, the Kauaʻi Invasive Species Committee, the Hawaiʻi Department of Agriculture and Biosecurity, and the University of Hawaiʻi at Mānoa coordinating detection and response.

Ramie moth caterpillars are known to be voracious feeders on māmaki and can rapidly defoliate plants that provide habitat and food for native species, including the Kamehameha butterfly. The caterpillars also feed on other native nettle relatives such as maʻoloa and ōpuhe. The species was first detected in Hawaiʻi on Maui in 2018, then on Hawaiʻi Island in 2020 and Oʻahu in 2025, making the Kauaʻi discovery the latest stop in a multi-island spread since 2018.

Officials stress that a single confirmed caterpillar suggests an early-stage incursion on Kauaʻi, and they are asking residents to be vigilant. Look for caterpillars, egg clusters, or adult moths on māmaki and on related host plants. Take clear photos from multiple angles, note the location, and report sightings immediately through the state’s invasive-species reporting portal at 643pest.org. The portal provides instructions for submitting photos and location data to help agencies track and respond to new sightings.

To help residents distinguish potential ramie moths from native caterpillars, officials recommend documenting where the insect was found and any feeding damage such as stripped leaves or sudden defoliation on māmaki, and then comparing photographs to identification resources available through state and university channels. Preserve samples when safe to do so and report them via the online portal rather than transporting suspect insects across the island.

The ecological stakes extend beyond individual plants. Rapid defoliation of māmaki and related species can undermine restoration plantings, impact native insect populations that rely on those plants, and complicate conservation work by state and nonprofit partners. Early detection increases the chances of targeted responses that can limit spread and reduce long-term management costs.

For now, Kauaʻi residents are the frontline of detection. Timely reports to 643pest.org and coordination with the Kauaʻi Invasive Species Committee and state agencies will shape the next steps in containment and monitoring. Continued vigilance and prompt reporting will determine whether this single detection becomes an isolated incident or the start of a broader response effort.