House committee advances funding to study nematode treatment for invasive longhorned beetle

The House Committee on Higher Education on Feb. 13 voted to pass House Bill 2139 (HD1), which would appropriate funds for research into treatment and control methods for the Queensland longhorned beetle (QLB).

Representatives from the Department of Land and Natural Resources said QLB has spread on the east side of Hawaii Island and threatens dozens of tree species, including native and culturally important trees such as alaheʻe, kukui and ulu, as well as economically important crops like cacao.

Researchers including Rebecca Ostertag (University of Hawaii at Hilo) described trials of a nematode biocontrol that have shown promising early results. Ostertag told the committee that in a preliminary sample of treated trees roughly 76 percent showed improvement and 24 percent held steady, and that additional funding would help optimize injection methods, improve scale‑up and support outreach to island communities.

Farmers and local practitioners described operational challenges, including limited availability of nematodes when funding is intermittent and the labor‑intensive nature of tree injections. Lila Shapiro, who works under Ostertag, said injecting trees with nematodes can lead trees to recover from heavy infestation but that techniques need refinement to be practical at scale.

The committee noted the bill already contains an appropriation and a defect date and adopted the chair’s recommendation to pass it as is, forwarding the measure to finance. Supporters included the Hawaii Farm Bureau, the Big Island Invasive Species Committee and CGAPS (Coordinating Group on Alien Pest Species).