As wireworms spread across P.E.I., costing potato growers millions of dollars by damaging crops, farmers are turning to a new rotation crop for the fight.

Wireworms, the larval form of the click beetle, have become a serious agricultural pest on the Island in the last couple of years.

Brian Beaton

Wireworms are a serious threat, says Brian Beaton, potato coordinator with P.E.I. Department of Agriculture. (CBC)

"It's the population increase. That's what really shocked me, is how fast they have increased in number," said Christine Noronha, a pest control specialist with Agriculture Canada.

"The numbers has gone up tremendously. And how fast they've spread, because they used to be in just pockets on the Island."

Wireworms live in the ground, beyond the reach of insecticides sprayed on the surface. The insects dig holes in potatoes as they grow, making them unfit for sale. The pest cost the industry on the Island $6 million last year.

Brian Beaton, potato coordinator with P.E.I. Department of Agriculture, said the problem is spreading to other crops as well.

"We're seeing it this year in strawberries and grain crops and root crops like potatoes and carrots for sure," said Beaton.

"It is a serious threat."

pe-mi-wireworm-potato

Wireworms cause scarring on potatoes that make them unmarketable. (R. S. Vernon courtesy of Agriculture Canada)

Beaton said thousands of hectares of brown mustard have been planted this year as part of the battle against wireworm. Last year just a few hundred hectares were planted.

The plants are toxic to wireworms and studies have shown brown mustard and buckwheat are effective as natural fumigants, especially when planted two years in a row.

"The brown mustard produces a bio-fumigant in its roots," said Beaton.

"As you mulch up the whole plant and the plant gets broken down, there's a reaction that takes place and gives off the bio-fumigant into the soil to basically help to control and kill any disease and insects that may be present in the soil."

Noronha said there are multiple studies going on this year into controlling wireworm, including more research into brown mustard and the best way to use the crop to keep wireworm populations in check.