The correct way to eat a cockroach, at least in this corner of northern China, is to fry it not once but twice in a wok of smoking hot oil.
“The second time makes the shell crispy and the inside succulent,” said 43-year-old Wang Fuming, as he tipped a bowl of freshly harvested bugs, one or two of their legs still twitching, into the sizzling pan.
Mr Wang is the leading cockroach farmer in Shandong province, with more than 22 million of the insects living in a series of nondescript, concrete bunkers in the suburbs of Jinan.
After cooking, Mr Wang gently ladled them onto a plate, their bodies plumped with the oil and their wings slightly spread, before sprinkling a packet of instant noodle powder – pickled cabbage flavour – over the dish.
“It would be better if we had some chilli,” he apologised.
The cockroach, whose innards resemble cottage cheese, has an earthy taste, with a slight twinge of ammonia. But they have become popular in China not for their taste, but for their medicinal benefits.
“They really are a miracle drug,” said Liu Yusheng, a professor at the Shandong Agricultural university and the head of Shandong province’s Insect Association. “They can cure a number of ailments and they work much faster than other medicine.”
Sacks of dead cockroachs waiting to be shipped
Prof Liu said a cream made from powdered cockroaches is in use in some Chinese hospitals as a treatment for burns and in Korea for cosmetic facial masks.
Meanwhile, a syrup invented by a pharmaceutical company in Sichuan promises to cure gastroenteritis, duodenal ulcers and pulmonary tuberculosis.
“China has the problem of an ageing population,” explained Prof Liu. “So we are trying to find new medicines for older people, and these are generally cheaper than Western medicine. Also we have a tradition of eating bugs here in Shandong.”
For a decade, Mr Wang farmed another type of insect, Eupolyphaga Sinensis, which is also used in Traditional Chinese Medicine.
But in the past two years, the demand for cockroaches has soared, and Mr Wang has switched his entire production to Periplaneta americana, or the American cockroach, a copper-coloured insect that grows to just over an inch and a half.
“These are not the same ones you see in your home, those are German cockroaches,” he said. “There are hundreds of species of cockroaches, but only this one has any medicinal value. It is native to Guangdong province.”
Intrepid Telegraph reporter Malcolm Moore samples a fried cockroach
Inside his bunkers are hundreds of nests, bolted together from concrete roof tiles, that line the shelves of dark corridors.
The doorways are lined with mesh, but some cockroaches have clustered on the low ceilings overhead and the air is heavy with a fetid stink. “That is just how they smell,” Mr Wang shrugged.
Last month was harvest time across Shandong. As farmers elsewhere in the province picked apples and cut corn, Mr Wang reaped huge sackfuls of roaches.
“We kill them before they reach four months old, because then their wings are fully grown and they can fly,” he said. “They are very easy to kill, we take large vats of boiling water into the corridors and dunk the nests into them.”
His entire output is sold to pharmaceutical companies, he said, and the price has risen strongly. Since 2011, he has quintupled production, to more than 100 tons a year, and he has eight workers.
Outside his farm, another man is waiting to be shown around. Since this spring, Mr Wang has had 100 enquiries from would-be cockroach farmers and has helped to build 30 other farms.
“Oh, the money is good,” said Xiao Zhongwu, a wiry 49-year-old who has a smaller set of farms in the countryside near Qufu, the birthplace of Confucius. “I have a trucking business too, transporting marble, paper and farm products for local companies. But that brings in pocket money: it is cockroaches that bring in the big money.”
Mr Xiao said he had invested £160,000 in building a series of small farms, their windows taped over with plastic sheeting to stop the cockroaches from escaping.
But, he said, he earns at least £30,000 a year from the insects, and up to £90,000 in a good year. “The pharmaceutical companies set the price, but I stockpile my cockroaches when the supply is plentiful to wait for when the demand picks up.”
Mr Xiao feeds his cockroaches a “special formula” of mashed up vegetables and waste to produce the high levels of amino acids that his buyers demand.
But, he said, farming the bugs is very simple. “Just keep them warm and they are happy.”
Until now, the industry, while booming, has remained mostly under the radar. But in August, a million cockroaches escaped from a farm in Jiangsu province, making headlines in the Chinese media.
Wang Pengsheng, a 38-year-old former engineer, said he had bought the plot of land to raise the insects after six months of research into the industry. He bought more than 80kg of eggs for £10,000 and set up his farm.
But while he was out inspecting the goats and pigs he was raising elsewhere, the local government deemed his building illegal and knocked it down.
“When I came back in the evening, everything was gone, reduced to rubble,” he said. “Afterwards, a team of exterminators came around to try to kill all the escaped cockroaches.”
Mr Wang said he was determined to start again. “The problem is that the government has been under pressure from people saying the cockroaches are pests and they should not let me rebuild.”
In Jinan, the other Mr Wang said he had heard of the misfortune suffered by his namesake. But, he added, he has not had any recent break outs from his farm. “In the beginning a few got away. But since we covered all the windows and doors with mesh, they have been well trapped,” he said.
Additional reporting by Adam Wu