People who attempt to carry prohibited plants and animals into China via Shanghai now run the risk of being added to a credit blacklist that can make it difficult to apply for jobs, loans or public welfare.
Travelers caught with alien species twice in 12 months will be blacklisted for a year, while those who intentionally hide such contraband to evade quarantine face an automatic penalty, even for a first offense, under new rules.
"Severe violators may be held criminally liable," the Shanghai government's information office said in a post on Sina Weibo to promote the revised rules, which come into effect on Jan 1.
The aim is to prevent harmful invasive species from entering the country and affecting the agricultural industry, as well as food safety and environmental security, it said.
Employers, banks and local authorities are encouraged to use the city's credit blacklist to check the backgrounds of people who apply for jobs, loans or government subsidies.
Under the new measures, travelers who resort to violence or threats against entry-exit inspection and quarantine officials when found with contraband face three years on the list, as will those who attempt to destroy species found in their luggage.
People who reoffend within five years will see their penalty automatically extended by three years, the authority added.
China has a list of more than 400 banned nonnative species, according to the General Administration of Quality Supervision, Inspection and Quarantine.
Live animals, meat, dairy products, fresh vegetables, fruits, seeds and soil that may contain harmful species are barred from entry.
Banned items found in a passenger's luggage will be destroyed, while those discovered in mail parcels may be returned to the sender, the administration said.
Xu Hongzhi, an analyst at BRIC, a Beijing-based company providing agribusiness consultation services, said most travelers who bring in such banned items do so unintentionally.
"But the blacklist may serve as a stronger warning to the public that they must take seriously what they are bringing into the country. People cannot bring the seemingly harmless items at will by thinking such a small number of items will not lead to big consequences," he said.
The number of such forbidden items illegally carried and mailed into the country has increased rapidly as China's global interaction grows, and as shopping on overseas e-commerce platforms matures, Xu said.
Roughly 22,000 packages of plant seeds and sprouts－80 metric tons altogether－were intercepted at the country's entry ports in an eight-month campaign in 2015. Of those, 14,200 packages were found to contain harmful species.
Song Dunlun, an entomology professor at China Agricultural University, said one example showing the harm of alien species is whiteflies, which are known to damage vegetables. Native whiteflies have been largely replaced by nonnative silverleaf whiteflies in many parts of China over the past two years.
The silverleaf variety is more troublesome and new kinds of pesticides may be needed to kill them, he said.