Photo/IllutrationA red-necked longhorn beetle (Provided by Osaka Prefecture’s Research Institute of Environment, Agriculture and Fisheries)

  • Photo/Illustraion

Local authorities are seeking the public’s help to contain the spread of an invasive beetle species whose larvae can kill cherry, peach and other trees from the inside.

Officials are urging the public to be on the lookout for red-necked longhorn beetles. The insects usually lay their large number of eggs on trees around this time of year.

The first report of damage from the beetles came in 2012 in western parts of Aichi Prefecture.

Since then, red-necked longhorn beetles have been confirmed in Tokyo and Saitama, Osaka, Gunma, Tochigi and Tokushima prefectures.

The central government designated the insect an invasive alien species in 2018.

The Environment Ministry is warning on its website that “those who capture and keep red-necked longhorns or release them into the wild will be penalized under the law governing designated invasive alien species.”

The ministry urges the public to promptly contact local authorities whenever they see the insect.

Red-necked longhorn beetles typically measure 2.5 to 4 centimeters long and have glossy dark bodies and red-colored necks. They are indigenous to China, the Korean Peninsula and elsewhere.

Adult beetles emerge from host trees, such as cherry, peach, apricot and plum, and lay hundreds of eggs on the trees. The larvae develop by feeding under the bark.

In Aichi Prefecture, efforts to contain the damage by felling trees and using chemicals had positive results.

But in late June, the species was discovered in the prefectural capital of Nagoya.

In Osaka Prefecture, beetle damage has been reported in 11 municipalities.

In some prefectures, beetle sightings were reported, but no damage has been confirmed.

In 2017, Wakayama Prefecture announced the discovery of the insect.

In Nara Prefecture, authorities are investigating the extent of damage after red-necked longhorn beetles turned up in June this year.

At least one local government is offering a financial incentive to the public to detect the species before they can damage trees.

The Tatebayashi city government in Gunma Prefecture kicked off a campaign against the beetles in late May targeting residents and people who commute to the city for work or school.

A soft drink or 50 yen (48 cents) in cash is provided for each dead adult longhorn beetle brought in.

More than 2,000 red-necked longhorn beetles have been collected so far under the initiative, according to Tatebayashi officials.

“We are determined to eradicate the bug with a labor-intensive method,” a city official said.

The Sakai city government in Osaka Prefecture last year started calling on citizens to post locations where the beetles have been spotted, as well as images of the bugs they find, on its website.

The Saitama prefectural government has been making similar efforts since last year, urging people to report sightings of the species by e-mail.

Saitama officials said reports from citizens pointed to 250 sites last year. Of these, 128 had signs indicating the existence of adult beetles or larvae.

Many local authorities have heightened their level of caution to contain the bugs, even though no beetle damage has been confirmed in their jurisdictions.

The Fukuoka prefectural government is educating local authorities about features and biology of red-necked longhorn beetles through its website so that they can respond swiftly if the species is discovered.

“We are determined to respond before the insect makes a home here,” a prefectural government official said.