TAIPEI (Taiwan News) — Japanese rhinoceros beetles in central Taiwan breed in June as they become more active and visible, but their numbers are in steep decline.
Lin Shu‐ling (林淑玲), an administrator of a local community environmental class, noted that beetle counts in Xihu have dropped sharply over the past two years, especially along the Dongluo River, per CNA. Part of the problem is aging Griffith’s ash tree trunks, which make it harder for the beetles to chew through bark and feed on sap.
At the end of last year, the community class launched a rhino beetle trail along the river and planted 10 new ash trees—bringing their total to 20—in hopes of restoring the local population. The number of beetles did rise this year, with 20 to 30 spotted on some trees.
However, the population has plunged again in recent days, according to lecturer Hsieh Wen-you (謝文猷). He said environmental factors have been ruled out and that human activity is likely to blame.
Hsieh spotted several people catching beetles and taking them home during a Tuesday morning visit to Xihu Central Park. He has since organized a volunteer beetle patrol to visit the area five times daily from morning to night.
Patrol members will explain beetle ecology, remind visitors not to capture the insects and keep a detailed log of beetle sightings.
Hsieh said residents can still enjoy viewing beetles in other ash-tree areas—such as around Qingshuiyan Temple in Shetou Township and Xihu Hunan Elementary School—but should not remove them.
Ecological photographer Minos (米諾斯) posted on social media that he saw migrant workers at the Maoluo River on Saturday hitting trunks with sticks and filling buckets with beetles. He tried to persuade them to stop but was ignored.
Minos noted that fried beetles are a delicacy in some Southeast Asian countries and suspects the insects were being collected for food or sale.
Japanese rhinoceros beetles are not a protected species, and current laws make it hard to fine people who remove them from public ecological areas.
Officials urged the public to use moral persuasion to protect the beetles, ensure they can mate for future generations and maintain ecological balance.
