A National Taiwan University research team unveiled the results of a seven-year bee study April 14 in Taipei City, demonstrating how collapse of the insect’s colonies might be linked to a certain pesticide.
The study shows the pesticide called imidacloprid can seriously harm worker bees’ sense of orientation, smell and learning ability, NTU professor and team leader Yang En-cheng said. Bees instantly lose their ability to return to hives after given a 50 parts per billion solution of the pesticide, he added.
Research also shows that as the team increased the solution concentration, more bees were affected and lost their way to the hives, Yang said. Since colonies depend on worker bees to collect honey and pollen, once they are disoriented by the pesticide, the colonies face the specter of collapse.
Yang said that even if worker bees make their way back to the hives, they might still pass some of the pesticide to younger bees, damaging neurological systems.
As the annual output value of bee products in Taiwan is NT$2.3 billion (US$76 million), Yang said, bee colony collapse poses a serious problem. More than 40 kinds of local agricultural produce depend on bees for pollination, he added.
The researchers gave 600 bees solutions of five different imidacloprid concentrations. Comprising NTU professors from the fields of bio-industrial mechanics engineering, electrical engineering and entomology, the cross-discipline team utilized far-infrared ray, image recognition and radar to track the location of the four observed colonies.
Yang said though worker bees usually return to their hives within five minutes after collecting honey, the study shows the bees became restless, repeatedly used their sensors to scratch their eyes, stopped flying and even died after being given a solution of 40 ppb of imidacloprid.
The EU banned farmers from using imidacloprid and other nicotine-derived systemic insecticides in 2013 to protect bee colonies, but the product is still allowed in Taiwan, Yang said.
In response, the Council of Agriculture under the ROC Executive Yuan said it has implemented a series of evaluation procedures to consider limiting or prohibiting farmers from using insecticides that pose a high risk for bees, including imidacloprid.
The agency has also directed local pesticide manufacturers to carry labels warnings of the effect of their products on bees, the COA said.
Starting November 2013, the council requires manufacturers to provide product testing information on their products’ impact on bees when registering new pesticides.
