LETHBRIDGE – Cabbage seedpod and pea leaf weevil were the pests responsible for the greatest amount of crop damage in Alberta in 2007, but they aren’t the only pests plaguing Alberta farms, says Scott Meers, an insect management specialist with Alberta Agriculture.
He advised farmers attending an Irrigated Crop Production Update meeting in Lethbridge to watch for the following insects this year:
Canola
Cabbage seedpod weevil
This weevil will be the major insect problem in canola this year, based on the record numbers found in crops last year.
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“We have never seen them that high,” Meers said.
He warned producers growing early varieties of canola to check their fields as soon as the canola comes in flower. The field first in flower will attract the cabbage seedpod weevil in the highest numbers.
“You will almost certainly have damage in southern Alberta,” he said, adding that canola grown south of the Trans-Canada Highway will need to be scouted.
So far it has not been found in the Peace River area.
Bertha armyworm
A variety of agriculture organizations from across the province monitor a trap line to check for the insect.
Meers hopes to have a forecast map out later in the season to help farmers control any significant damage.
No significant spraying occurred for bertha armyworm last year and Meers said he hopes levels will be low.
“It’s possible the infestation has run its course.”
Diamondback moth
Provincial agencies monitor 20 sentinel sites to keep track of the moth. It overwinters in the United States and arrives in Canada on the wind. Officials are trying to figure out the wind patterns that bring in the moth.
Improved pheromone traps are being developed to make better infestation predictions. Most of the damage is done immediately before harvest when the insect eats the outside of the pods and causes shattering.
Salt marsh caterpillar
The hairy, yellow caterpillar is not an economic problem in the province, but its fuzzy look generates lots of calls to Meers.
Swede midge
The insect was first found in Ontario in 2000 but hasn’t yet been found in Alberta. Last year it was discovered in three locations in northeastern Saskatchewan. The midge looks like a tiny, orange mosquito and has become a problem in cole crops.
Cereals
Hessian fly
This insect is found mainly in the Drumheller and Carbon areas.
Slugs
Slugs showed up in about a half a dozen canola and cereal fields in Alberta last year. Farmers who suspect slugs in their fields should contact Meers.
“It’s one of those weird things that may be a developing problem,” he said.
Cereal leaf beetle
The beetle was discovered in Alberta in 2005 and has become established in the Lethbridge area. It’s also been found in significant levels in winter wheat and has the potential to affect all prairie wheat-growing areas.
Meers said the good news is that a parasitoid that helps control the beetle has been discovered.
“If we do get global warming and warmer summers, the beetle will do even better,” Meers said.
Wheat stem sawfly
Sawfly pressure has backed off except in the Foremost and Bow Island areas.
Generally most of the area has less sawfly population than in previous years.
Grasshopper
A significant resurgence of grasshopper numbers is occurring in the Peace River country, around Edmonton and northwest of Edmonton. Grasshoppers are also increasing in southern Alberta but are not yet at worrisome levels.
Pulses
Pea leaf weevil
Meers said this is expected to be the second most significant insect in southern Alberta in 2008. Adults eat the leaves of pulse crops and the larva eat the nodules, which damage nitrogen fixing benefits. The weevil has been discovered as far north as Olds and in high levels from Medicine Hat to High River. Meers said producers who grow peas south of the Trans-Canada Highway should have a control strategy.
Mite in timothy
The mite appears to be new species and it doesn’t seem to matter if the timothy is irrigated. It is mostly showing up in stands of timothy five years or older.
Alfalfa blotch leafminer
This insect creates holes in the plants. The leaflets fall off if the alfalfa is significantly infested. The good news is a parasitoid that controls the insect and appears to have been introduced with it.
