Announcing its bees policy in Castlemaine yesterday, State Opposition Leader Ted Baillieu said at least 400 hive sites had been banned by Parks Victoria and the Department of Sustainability and Environment in the past 20 years.

''The honey bee industry has been doing it tough over recent years, obviously the bushfires and the drought have had an impact, but also there has been an abandonment of sites by this State Government,'' he said.

The Opposition said the Government had promised to investigate half of 400 lost sites identified by the beekeeping industry by August, but just 98 had been assessed to date with only 21 sites to be re-opened.

Apiarist Trevor Monson welcomed the Coalition policy, saying access to public land was crucial to the the bee and agricultural industry expanding.

Mr Monson's company, Monsons Honey, across the border from Mildura, has five hive sites on Victorian public land and 45 in NSW.

He said the growth of other industries was reliant on beekeeping, citing the pollination of Robinvale almond trees this August where 70,000 hives were needed, but only 30,000 could be sourced from Victoria.

''There simply wasn't the quantity from Victoria, so the rest came from NSW and Queensland,'' Mr Monson said.

The number of public sites has been eroded, he said, including under the former Liberal/National government.

A spokesman for Environment Minister Gavin Jennings said DSE and Parks Victoria were completing an assessment of 200 ''lost'' or discontinued bee sites with a view to returning as many as possible.

There are about 200 commercial beekeepers in Victoria and up to 80,000 hives.