Neurozerra conferta (Lepidoptera: Cossidae) damaging Melaleuca plantations in Vietnam and its biological control

Melaleuca leucadendra and M. cajuputi are grown widely in Vietnam, with plantation areas in 2020 of 32,000 ha and 36,000 ha respectively. A stem borer, Neurozerra conferta (Walker) (Lepidoptera: Cossidae), has significantly damaged plantations of both species. Field surveys in 2021 found N. conferta damage to M. leucadendra in the four provinces of Ninh Binh, Long An, Dong Thap and Kien Giang with a damage incidence (P%, percentage of plants attacked) of 22.4–33.2% and an average damage index (DI) of 0.77–1.01. In Long An province, surveys in 2022 found frequent damage to M. leucadendra plantations at the age of 2–3 years with P% ranging from 22.7 to 27.3% and DI from 0.46 to 0.54. Beauveria bassiana and Metarhizium anisopliae were identified as potential biological agents with control effectiveness of 59.6–63.3%. Screening to identify resistant varieties of M. leucadendra and development of an integrated pest management strategy for N. conferta are recommended.