Beekeepers brace for killer parasite

The small hive beetle is causing alarm among Swiss beekeepers. National Bee Unit

Swiss experts want tighter import restrictions on bees to prevent the introduction of a parasite which has decimated hives in the United States.

But they concede it is only a matter of time before the small hive beetle spreads to Switzerland where conditions are ideal for it to reproduce rapidly.

The beetle, which kills bee larvae and destroys honeycomb, can infest live bees, honey, beeswax and other bee products.

“We fear this parasite is likely to spread to Europe at any moment, especially since we know that more than 1,000 hives were imported from the United States into Germany in spring 2003,” Anton Imdorf, an agro-engineer at the Swiss Bee Research Centre, told swissinfo.

A risk assessment of the dangers posed by the small hive beetle to the country’s 200,000 bee colonies was completed by the Federal Veterinary Office earlier this year at the request of the Bee Research Centre and the apiculture industry.

The study concluded that should the beetle reach Europe, there was a “very high” risk of it spreading to Switzerland, where it would thrive in the moderate climate.

“In view of the density of the bee population, the lively trade in colonies and frequent exchange of products and equipment, it can be assumed that infestation would spread throughout Switzerland within a few years,” said the report.

“The consequences for individual beekeepers are assessed as medium to high. The parasite is capable of destroying large numbers of colonies… There are no reasonable grounds to believe the beetle can be eradicated.”

High cost

The Federal Veterinary Office says a drastic decline in the number of hives could also lead to a significant reduction in pollination of cultivated and wild plants.

Pollination by bees is worth SFr268 million ($209 million) to Swiss farmers every year, according to the Swiss Bee Research Centre.

Britain’s National Bee Unit has reached similar conclusions about the threat posed by the small hive beetle, which is indigenous to southern Africa.

British bee inspectors began surveillance programmes last year, targeting hives close to airports and ports.

In December 2003 the European Commission also reacted to the threat from accidental imports of “exotic bee pests”, including the small hive beetle.

It introduced legislation strengthening controls and the certification requirements for the importation of bees from outside the EU.

The new regulations include a ban on imports of live bees from infected countries and mandatory tests for all imported bees.

EU regulations

The Federal Veterinary Office wants Swiss import requirements to be brought into line with EU regulations.

Urs Zimmerli, who works for the office’s import and export unit, told swissinfo that this was unlikely to happen within the next few months.

But he stressed that existing regulations were effective: anyone importing bees into Switzerland needs a permit and there is a ban on bees from infected countries.

“There are no risks with the way the system works today – at least as far as legal imports are concerned,” he said.

However, Zimmerli admits that even the tightest restrictions are not going to keep the small hive beetle out of Switzerland.

“When it gets to Europe there is little that can be done, so import restrictions are unlikely to make much difference. We would like to delay the problem as long as possible to give researchers more time to develop ways of controlling the problem.”

Fighting back

The Swiss Bee Research Centre, which is part of Agroscope Liebefeld-Posieux, the Federal Research Station for Animal Production and Dairy Products, is already on the case.

Scientists expect small hive beetles in the US will soon develop resistance to the only pesticide available, and Swiss and German researchers are now focusing on a natural remedy.

They are testing a combination of organic acids and essential oils which has proved effective against the Varroa destructor parasite and is now used by 80 per cent of Swiss beekeepers.

The Varroa destructor arrived in Switzerland in 1984 and went on to wreak havoc on the beekeeping industry, destroying around 100,000 hives.

Imdorf believes beekeepers now face an even greater threat in the shape of the small hive beetle.

“Fundamental research on the biology and behaviour of the small hive beetle is needed to get a better understanding of the parasite and the interactions with its host, the bees,” he said.

swissinfo, Adam Beaumont

Key facts

There are around 20,000 beekeepers in Switzerland and 200,000 hives.
The Swiss beekeeping industry produces SFr65 million worth of goods a year.
Pollination by bees is worth SFr268 million a year to Swiss farmers.

In brief

Adult beetles can survive for two weeks without food and water, for 50 days on used comb and for several months on fruit.

Their larvae tunnel through honeycomb to eat bee larvae, and their excrement ruins stored honey. Badly infected colonies have to be destroyed.

Adults can fly more than seven kilometres to infest new colonies.