Armyworm infestation decimates B.C. crops

Port Alberni farmer: ‘A seething mass’

An army of voracious worms is on the munch in B.C., leaving a trail of withered grass and corn in its wake and forcing some farmers to harvest their crops early.

True armyworm, or mythimna unipuncta, is a larvae that was first identified in early July on Vancouver Island, said Tracy Hueppelsheuser, an entomologist with the Ministry of Agriculture.

As the hungry insects advanced, hay crops disappeared almost overnight. At the end of August, the pests were discovered in the Fraser Valley, and since then, have been found in a number of fields in Delta, Surrey, Abbotsford, Deroche and Chilliwack.

The damage can occur very quickly,” Hueppelsheuser said. “They seem to come out of nowhere, but in fact they were likely there for some time.”

Port Alberni farmer Ann Collins and her husband decided to harvest their summer hay crop early to prevent the bugs from eating it, getting 25 large round bales off land that usually produces about 125 bales.

“They come in hordes,” Collins said. “The fields become a seething mass. When I first saw them, I thought they were snakes.”

On Friday, Collins also sold and butchered half her beef cows rather than buying hay to feed them through the winter.

“I’m just thankful we’re retired and we can afford to downsize,” she said.

At Glen Alwin Farm near Courtenay, Helen Smith opened her farm gates last week, allowing her cows free range in a field plagued by the insects. As a result, she’ll have less hay to sell this winter.

Blown to B.C. by spring storms in Mexico and the southern United States while in the moth stage of their life cycle, armyworms drop out of the clouds in search of lush, green grass to lay their eggs. When the larvae hatch in early summer, they begin to eat, feasting on mouthfuls of grass for four to six weeks, Hueppelsheuser said.

After the initial outbreak on Vancouver Island in July, the armyworm larvae burrowed into the ground for several weeks, emerging as large, heavy-bodied moths.

After they laid their eggs, the cycle began again.

The second outbreak, which now includes the Fraser Valley, appears to be larger than the first, said the entomologist.

Although the moths have been found in B.C. in the past, it’s the first time they’ve been recorded in significant numbers.

There are several Health Canada-approved insecticides that can kill armyworms, but they are most effective in the early stages of an outbreak.