Sac brood disease
In June, 2015, it was suspected that wild bees in the Chiayi region in Taiwan had contracted sac brood disease. In September, 2015, it was confirmed that sac brood disease had occurred, and that infected bees were smuggled into Taiwan from Zhejiang on the Chinese mainland. Professor Chen Yu-wen of Yilan University found that the viral stem of the virus of sac brood disease was the same in the infected bees in both Zhejiang and on Taiwan. Since Taiwan is an island, bees on the Chinese mainland would not have been able to infect the Taiwanese wild bees unless diseased bees were smuggled into Taiwan and released on Taiwan. It is estimated that these infected Zhejiang bees were smuggled into Taiwan some 4 to 5 years ago (2011-2012). The wild bee population in the Changhua and Taiwan plain has already been decimated, and the disease is beginning to spread to central and parts of northern Taiwan. As a result, pollination will be reduced, and a healthy wild bee population will require 10 to 20 years to recover.