Greek experts have expressed concern for the unexplained disappearance of large quantities of honey bees.

Greek scientists are watching out for Colony Collapse Disorder, which refers to the mysteriously abrupt departure of worker bees from their hives, Kathimerini reported Saturday.

"We are on the alert. If CCD appears in Greece, the consequences could be massive," Agricultural University of Athens Professor, Paschalis Harizanis said.

The European Union relies on Greece, one of the world's biggest bee settlements, to produce 14,000 tons of honey each year. The country is the European Union's third-top producer of honey.

Colony Collapse Disorder has reportedly been a problem for the United States, Germany and Switzerland.