Rare rainbow stag beetle with both male, female characteristics found in Osaka

OSAKA -- A rare rainbow stag beetle with both male and female characteristics has been found at the home of a breeder here.

In March, while replacing the soil in a breeding case, Takaaki Irizawa, 34, an office worker living in Osaka's Miyakojima Ward, spotted an adult rainbow stag beetle without one of its mandibles. At first, he thought that his breeding was at fault, but upon closer inspection, he found a short jaw on the left side, so he consulted the Osaka Museum of Natural History in the city's Higashisumiyoshi Ward. After having the museum look at the insect, it was determined that the stag beetle was a gynandromorph, or a sexual mosaic.

Shunpei Fujie, a curator in charge of beetles at the museum, said, "I've seen hundreds of thousands of insects, but this is the first time I've seen a live gynandromorph." He said that many sexual mosaics are not capable of reproduction, and he expects that the one found "will probably live a long life because it will not engage in reproductive activity." "We hope that it will be carefully nurtured," he added.

The rainbow stag beetle, mainly inhabiting Australia, is often called "the most beautiful stag beetle in the world" because of its iridescent body. The one found at Irizawa's home was 56 millimeters in length, with the right mandible large like that of a male and the left one short like that of a female. The entire specimen has the characteristics of a male stag beetle, but female characteristics are also seen on part of its back and with its front left leg.

Irizawa, who had always loved insects, began raising them in earnest when his son Taiki, now aged 6, became interested in insects at the age of 2. He has been engaged in breeding, hatching eggs and mating adult insects, and now has more than 100 of them, including large Dorcus hopei binodulosus stag beetles, known in Japan as "okuwagata."

Taiki said of the rare stag beetle, "I thought it was gross when I found it, but now I think it's cute." He and his older sister, Sae, 7, have named the stag beetle "Shiyuchan" and take good care of it.

Irizawa told the Mainichi Shimbun, "I hope that through breeding the insects, my children will learn the preciousness of life and the wonders of ecology."

(Japanese original by Koji Minemoto, Osaka City News Department)

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