PARIS-In the romantic city of lights, the bees are downright busy.

Common sense says it is better to keep hives of stinging insects in the countryside, away from city centers packed with people. Yet on storied rooftops and public gardens in the urban jungle of Paris, the bee business is thriving.

Bees are disappearing from fields across France and elsewhere in the world, victims of a slow decline in number because of loss of habitat compounded by a recent and mysterious catastrophe variously blamed on disease, parasites and pesticides. The most recent science research points to a combination of interacting diseases for new collapses of bee colonies.

But in the heart of the French capital, Nicolas Geant is preparing to sell off his honey. It comes from hives on the edges of the soaring glass roof of the Grand Palais exhibition hall, just off the Champs-Elysees.

“Paris has many balconies, parks and avenues full of trees and little flowers that attract many bees for pollination,” said Geant, who has 25 years of experience under his belt.

The Grand Palais beehives went up in May. They also sit in the Luxembourg Gardens, on the gilded dome of the 19th Century Palais Garnier and the roof of the ultramodern Opera Bastille.

“In Paris, each beehive produces a minimum of 50 to 60 kilograms (110 to 130 pounds) of honey per harvest, and the death rate of the colonies is 3 to 5 percent,” said Henri Clement, president of the National Union of French Beekeepers.

“But in the countryside, one beehive only gives you 10 to 20 kilograms (about 20 to 40 pounds) of honey, and the death rate is 30 to 40 percent. It is a sign of alarm.”