They are battling disease, drought, pesticides, urban expansion, climate change and a mysterious plague known as colony collapse disorder.

Des Cannon, the editor of the Rutherford-based Australasian Beekeeper magazine, and Largs beekeeper Warren Millington say the situation has slashed honey supplies worldwide and is likely to increase the price of food generally.

Bees pollinate vegetable, fruit and nut crops and a variety of agricultural products, including grains and crops used for bio-diesel.

The biggest threats in coastal areas such as the Hunter were urbanisation overtaking native habitat, an exotic beetle that covered hives with slime and drought reducing the flowering of plants, Mr Millington said.

Mr Cannon said disease, including the deadly mite varroa, had had a devastating effect on bees in every country except Australia, and the disorder had seriously hit northern America, Britain and many parts of Europe.

Microbes, thought to be part of the disorder epidemic, had now been found in Australia, Mr Cannon said.

Mr Millington said: "Varroa wipes out feral bees and I think it's only a matter of time before we have it here.

"If that happens, beekeepers will have to supply bees for pollination, as is common practice in other parts of the world, and that increases the cost of food production."