These soybean-size beetles are the source of mysterious holes that appear in otherwise beautiful mamaki leaves with no apparent caterpillar, moth, or aphid to be seen. The Chinese rose beetle hates light so it buries itself during the day and comes out for only a few hours after dark.
It’s interesting that the beetle seems to favor the soft, large leaves of young mamaki plants. The tougher, small leaves on more mature plants are ignored…at least when the younger ones are available.
Control suggestions include adding lights in the garden for a few key hours to disrupt the beetles’ natural feeding and breeding cycle. Another suggestion is to go out at night and kill the beetles by hand while they are visible. For larger farms, an expert in other plant crops suggests that BotaniGard has been used successfully against Chinese rose beetles.
Recommended articles on the Chinese Rose Beetle
- Journal of Insect Science: Distinguishing male and female Chinese rose beetles
- Tropical Gardening Helpline: Remedies to your Chinese rose beetle problem
- U of H at Manoa Master Gardener Program: Chinese Rose Beetle