Manitoba honey producers are scrambling to stay one step ahead of deadly parasitic mites that have been devastating colonies south of the border.
The African varroa mite is becoming resistant to its main killer, Apistan, a United States bee expert told Manitoba beekeepers during the annual convention here two weeks ago. The chemical’s active ingredient, fluvalinate, kills the mites that feed on bee larvae without hurting the bees.
One beekeeper here says rather than finding new chemicals, the answer might be to breed strains of bees resistant to the mites.
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It seems to be working for the more common tracheal mite, said Terry Fehr, who operates 950 colonies near Gladstone.
“It’s not an exact science but we can narrow down a number of different strains which seem to be more resistant to the tracheal mite,” Fehr said.
He’s been working with the Ontario Beekeepers’ Association on research into resistant strains. By sending some sample bees to Toronto labs once a year, Fehr said the group is making some headway.
It won’t be as easy with varroa mites, first discovered in Canada four years ago.
“I don’t have varroa mites yet, but I fully expect to in a year or two,” Fehr said. Some of his neighbors have varroa now. Both strains of mites spread easily between nearby colonies.
Fehr said he’s been able to control the tracheal mites using a few household baking ingredients, vegetable oil and icing sugar.
Producers mix the two together to form a patty and rest it on top of the hive. Bees eat the mixture, and the oil has been shown to drastically reduce the transfer of mites from the older bees to the younger ones.
“Nobody knows exactly why it works, but it does,” said Fehr.
Some strains of bees seem to be more resistant to varroa mites than others, he said. Hygenic strains, for example, will clean some of the varroa off themselves and restrict the extent of the infestation.
Without treatment, varroa mites can kill an entire colony in two years, Fehr said.
Apistan is applied using strips containing the chemical inside the hives.
Resistance to the product is likely a result of improper use, Fehr said.
“Leaving the strips in longer than you should, not applying enough strips and some people even put together their own home remedies,” he said.
“It’s all to save a few dollars but there are now mites that are resistant to it and they will spread so the longevity of this chemical is very limited.”
Apistan is the only chemical registered in the U.S. to fight the mites.
In Canada, producers have the option of using formic acid, which still works but is much more labor intensive, Fehr said.
Producers here watching the mite’s resistance are heeding warnings from their counterparts south of the border. Fehr said keepers can alternate use of the two chemicals available in Canada to slow down the resistance factor.
But resistance mites will not be warded off forever, he said.
