Three thousand queen bumblebees from Belgium that arrived in Qingdao, Shandong province, a few days ago are expected to give a boost to greenhouse crops in northern China, as spring plowing gets into full swing across the country.

The insects are now undergoing 30 days of customs quarantine. Upon completion, they are expected to form nearly 3,000 bumblebee swarms, which could pollinate 300 hectares of greenhouse crops, including tomatoes, strawberries and blueberries.

"The market has seen an increase in demand for imported bumblebees in recent years, as the swarms' pollination efficiency is usually five to 10 times faster than that of honeybees," said Wei Hongjiang, sales manager at Biobest China, a biotech company. The company deals with the importing of queen bumblebees and is based in Shouguang, Shandong, the country's major vegetable producer.

Biobest, headquartered in Westerlo, Belgium, has 30 years of expertise in using bumblebees commercially.

Wei said his company has been importing the queen bumblebees from Belgium since 2014, and the business has grown at an average of 40 to 50 percent annually. The clients are mainly farms in Shandong, Liaoning and Hebei provinces, as well as in Beijing and Tianjin, and include some large agriculture projects, such as high-tech greenhouses and major blueberry producers in Yunnan province.

"The imported queen bumblebees have strong reproductive capabilities and the swarms they form are usually of high vitality," said Wei, adding that efficient pollination can improve the quality of crops. In addition, he added, they save labor.

Zhang Zhiguo, a farmer in Dongying, Shandong, grows tomatoes. Five years ago, he started using bumblebees for pollination, instead of traditional hormone treatment.

"With the help of the bumblebees, I can produce more tomatoes than before, with good taste and better shape. They're easier to sell at a good price," Zhang said.

Wei said he is looking forward to business expansion in the coming years, as China encourages tech-savvy and environmentally friendly agricultural production methods.

"Our company plans to offer solutions for natural crop care in the near future, aiming to help growers achieve quality and residue-free produce," he said. "For example, we will introduce natural enemies for pest control, and that means growers can cultivate more healthy vegetables."

Customs officers are now closely watching the physical condition of the queen bumblebees and will conduct laboratory tests to determine whether they carry diseases.

"We will continue to monitor the use of bumblebees after they are handed over to importers or growers," said Zhan Yifei, a Customs officer at Qingdao Liuting International Airport.