Release Guerrillas? :-)

[neil at nwjones.demon.co.uk]

The Japan Times: Aug. 26, 2003

Chinese butterflies invading Kanagawa

Butterflies normally seen in China have found a home in Kanagawa Prefecture because of illicit importation and breeding, posing a major threat to the local ecosystem, according to researchers in the prefecture.
 
Hestina assimilis, a variety of the nymphalid butterfly normally seen in China, is making its presence known in Kanagawa Prefecture.  

The researchers blamed the settlement of the butterfly, Hestina assimilis, on breeders, whom experts call "release guerrillas."

Such breeders secretly raise foreign varieties of insects and release them in the domestic environment.

Importing live butterflies into Japan is prohibited.

Hestina assimilis, a variety of the nymphalid butterfly, has a wingspan of 7 cm to 9 cm, and usually is found in China, Taiwan and Amami-Oshima Island in Kagoshima Prefecture.

By analyzing patterns on the wings, the researchers determined the butterflies found in Kanagawa are similar to those in southern China.

"It's unlikely the wind brought them to Japan," said Masatoshi Takakuwa of the Kanagawa Prefectural Museum of Natural History. "All we can say for sure is that someone released the butterflies after bringing them into Japan."

This variety of butterfly was first caught in Japan in 1995 in Saitama Prefecture, but it apparently did not settle there, according to the researchers.