When autumn comes, Lin Yujun starts taking photos of crickets and delivering them to his customers across the country.

Lin, 38, a cricket shop owner in Lanling Flower Market on Lingshi Road in northwest Shanghai's Putuo District, said his family has been running the cricket business since his father's generation.

Originally, they only sold the cricket pots and now he sells crickets and tools both online and offline. The price of his crickets range from 100 yuan (US$14) to 3,000 yuan each and the business is good, especially in September and October.

Cricket fighting is a traditional pastime of Chinese people dating back to the Tang Dynasty (AD 618-907) and thrived in the Southern Song Dynasty (1127-1279).

A Song Dynasty book described a scene at the time: "When autumn came, there were about 30 to 50 people gathering for cricket fighting in the downtown market every morning. The activity would run until the end of September (lunar calendar)."

Chinese people's bug passion reached a peak during the Qing Dynasty (1644-1911) and has maintained.

"I remember very clearly that my dad would take out cricket pots left by my grandfather every year after midsummer," said Gu Jiaming, 40, whose interest in insects started when he was a young boy.

Gu used to live in an old house surrounded by fields in northern Baoshan District. His father often rode bikes with him along the dirt lanes to look for crickets. Later, he learnt the tricks and went out hunting with his friends.

"We listened to the sound of crickets under the trees. When the crickets crowed, we flipped the stones in the grass to look for them and caught them with nets," Gu recalled.

"Once we caught the crickets, we put them in a bamboo tube and stuffed the opening with newspaper. Although I often had a lot mosquito bites on my legs, I was quite happy."

Picking a fighter

The cricket-fighting season usually begins in early September, when all the cricket-keepers start to catch and choose the best fighters in the field or in the markets.

To sort out a fighter from thousands of crickets in the market is like selecting a blind box. It is also the fun part of this hobby.

"Generally speaking, a good cricket's thighs are long and thick. Its body is strong and teeth wide," a shop owner, surnamed Lin, said. "If you find such a cricket, it must be a winning general."

The best-quality crickets in China mainly come from Henan, Hebei and Shandong provinces.

"Most of the vendors in this market are from Shandong," said Shangguan Maowei, 30, a cricket vendor who brought hundreds of crickets from Shandong to Shanghai last month. "I sell dozens of crickets every day and make around 1,000 yuan."

Some local vendors also travel to those provinces to purchase crickets.

Ye Shenkang, 60, has just spent a month in Shandong's Tai'an. "I started to collect crickets at 4am every morning and sent back some 100 crickets every three days," said Ye. "It's like traveling and meeting old friends. I enjoy it."

To raise a fighter, one needs special skills.

According to the ancient book written in the Southern Song Dynasty, people usually caught crickets before the solar term of bailu (White Dew, September 7 or 8), kept them for 30 days, and held cricket fighting after qiufen (Autumn Equinox, September 23 or 24).

Han Jiangyue, 36, an experienced cricket keeper, revealed some secrets.

"First of all, food is the most important. It makes crickets strong and should include grain and meat," Han said.

A fighter also needs company. Usually, one male cricket will mate with five female crickets in 30 days, according to Han. The insects usually get active at night, so the keeper needs to get used to its habits.

Time to fight

Before the fighting, two crickets need to be weighed like boxers. Then they are put into a container and teased with grass sticks.

The fighting time varies from one second to several minutes. If a cricket runs away, its opponent wins.

"Male crickets are born to fight for their mates, so it's hard for the losers to cheer up again," Han said. "Most people would throw the losers away or feed them to other animals."

However, Gu has a different point of view. "When I was young, I kept the losers and tried to help them regain their glory. Maybe this was an empathy for the weak. It brought me more happiness."