●About the Aromia bungii

The Aromia bungii is an invasive species of longhorn beetle native to East Asia. It feeds on the internal tissues of trees such as cherry, plum, and peach, causing them to weaken and eventually die. Under Japan’s Invasive Alien Species Act, it is designated as a Specified Invasive Alien Species.

In Japan, the species was first discovered in 2012 (Heisei 24) on cherry trees in Aichi Prefecture. As of the end of fiscal year 2025 (Reiwa 7), its presence has been confirmed in 17 prefectures. In Shinjuku Gyoen, damage to 14 cherry trees was confirmed in 2025.

(Related website)
Collection of information links on the Aromia bungii: Ministry of the Environment
https://www.env.go.jp/nature/gairai/info_kubiaka.html (Japanese only)

●Initiatives in Shinjuku Gyoen

To preserve the garden landscape and ensure visitor safety, Shinjuku Gyoen will implement the following combined pest control measures in fiscal year 2026 (Reiwa 8) with the goal of preventing the invasion and establishment of this beetle.

Please notevisits to the park can be conducted safely.

・Damage surveys — Period: June to September
・Excavation and net wrapping, etc. — Period: As needed
・Trunk injection of pesticides — Period: June
Pesticide used: “Woodstar”
・Trunk spraying of pesticides
Date: Monday, June 29, 2026 (closed day)
(If it rains, postponed to the following week’s closing day. 　　Additional spraying may be conducted depending on pest conditions.)
Pesticides used:
・“Accel Flowable” (diluted 200 times)
・“Abroach BI” (diluted 5,000 times)
Area: Approximately 100 cherry trees near the areas marked with red circles on the map below

●If You Find an Aromia bungii in the Garden

Please report the date, time, and location of the discovery to the Shinjuku Gyoen National Garden Office:

TEL: 03-3350-0152

If possible, please capture the insect and prevent it from escaping before contacting the office.