The long, curved mandibles of the fighting stag beetles make clacking sounds on contact, as the crowd builds for another round of Beetle wrestling - an obscure but growing sport in a country where the beetle is scaling new heights of popularity.

The crowd gasps as a beetle lifts up its 7 cm opponent with its jaws and flings it off the log.

"I trained him by deliberately letting him fight against smaller beetles and got him into the habit of winning," said Shin Yuasa, the proud owner of Sumatra Hirata, the stag beetle which became champion in a beetle wrestling tournament recently in Tokyo.

Beetle wrestling is just one of the delights of Japan's growing ranks of live beetle collectors, whose rising population has spawned numerous specialty shops in Tokyo that sell the insects in all shapes, sizes and colours.

"I liked insects, even as a child," said Yuasa, gently stroking the broad back of his beetle.

"The shape, the black colour, how it shines and the smart appearance of the beetle is what I like best," said the father of two children and owner of 30 beetles.

Price tags for a beetle range from a few hundred yen (a few dollars) to around 300,000 yen ($2,800), or even higher in some cases, and Internet sales are allowing collections to prosper in even far-flung regions of Japan.

Bigger is better in the world of beetles, and large foreign species command the top prices.

A mere millimetre in size could change the price by more than a hundred dollars. Last year, a stag beetle was reported to have been sold for as much as 10 million yen ($94,210).

Foreign beetles

To the delight of beetle fans, Japan eased restrictions last November on imports of 44 more species in addition to the four which were already allowed.

The insects, most of them stag beetles, were allowed as they feed on rotten wood and leaves and are therefore not seen as a threat to the ecology.

The beetles found in the jungles of Indonesia, Cambodia and India are generally larger than their Japanese counterparts.

There are no official figures available on beetle imports since the relaxation of rules.

But foreign beetles, some of which come in colours ranging from golden brown to iridescent green, have become hot favourites among collectors.

"At the moment, foreign beetles are ‘in,' but since everyone is going for them, it is getting harder to find domestic ones and that is giving them a sort of scarcity value," said Yukio Kawasaki, a beetle enthusiast.

"Each bug is attractive for a different reason - whether they are large foreign ones with exotic mandibles or indigenous Japanese ones," he added.

Bug experts hope the inflow of exotic beetles from overseas will give new status to the insects, which, for many people are still a childhood pastime rather than a serious pet.

"Over the last decade, it has got easier to raise and breed beetles so more people have access to them," said Hiroshi Fujita, editor of Gekkan Mushi, or Monthly Bug, an entomology magazine.

"Now with the arrival of new breeds and the attention they are getting, beetles could even become as popular as tropical fish," he added.

Bug loving people

Beetle wrestling is a relatively new way of enjoying stag beetles. But the Japanese fondness for insects is far from new.

Classical Japanese literature is full of references to chirping crickets, glowing fireflies and mayflies which die a few hours after they hatch.

In the days before video games, many Japanese children spent their summer holidays catching butterflies, cicadas and various types of beetles in nearby parks or forests.

Mothers would tell their young sons that they should grow up to become strong like stag beetles, or atlas beetles which have large, rhinoceros-like horns.

Bug experts reckon the childhood memories of hunting for insects and admiration for the hardy black beetles is what is sustaining the costly insect hobby.

Insect shops say men in their 30s and 40s are their best customers.

"A lot of the people who buy beetles now, have in their childhood experienced the joy of discovering a large beetle after searching for days," said Takamasa Suzuki, manager of insect specialist shop, Konchu Taikoku Waku Waku Land.

"Besides, beetles don't need much attention and rearing them is good for relieving stress," he added. "Some live as long as five years, which is longer than a life span of a hamster." (Agencies via Xinhua