On the lookout for Bertha

Source: Saskatchewan Agriculture and Food

In war, battles can be won or lost based on the quality of the intelligence about the enemy. Knowing your enemy’s position and strength can be a huge advantage.

Saskatchewan canola producers will have that advantage this year when it comes to a costly pest – the Bertha Armyworm.

Dale Risula, Integrated Cropping Management Systems Specialist with Saskatchewan Agriculture and Food, says there are a lot more people participating in the provincial monitoring program this year. This program monitors adult moths emerging from their pupae. The monitors use pheromone traps to catch the moths as they emerge from the soil.

“The number of people who are monitoring for us is up by 50 per cent, so that’s a pretty good indicator that there was some concern about this problem because of last year’s fairly wide-spread impact on canola growers,” Risula said.

Last year was a particularly bad year for the Bertha Armyworm, with significant crop damage in the northeast and east-central parts of the province.

Risula says the more monitors they have, the better the intelligence that is gathered.

“You get a better indication of where the outbreaks are taking place and a better representative sample of the moth counts that are out there,” he stated. “That will give us a better idea of what might take place this year, because it seems as though the moth count corresponds with the outbreak of worms. All of those things will add to the accuracy and understanding the intensity of any particular outbreak that might take place.”

A map of armyworm hotspots is prepared by SAF from the data collected by the monitors. This gives an early warning to producers in areas of potentially high risk. Knowing that information can help in many ways. For example, chemical companies will be able to have insecticide readily available in particular areas where an outbreak is likely.

“It’s important that people are aware of these pests when they show up, and then properly assess the numbers on a field-by-field basis to determine whether or not action needs to take place. Spraying for the sake of spraying may be more costly than beneficial.”

Of course, Mother Nature herself may help win the battle before the war begins. Risula points out that there are a number of environmental and biological factors that could dramatically cut armyworm numbers either before or after they emerge.

“The worms are subject to different types of predators, parasites and disease that are out there. In particular, there is a type of fungus that affects the larva. If that fungus happened to be fairly severe last year, in the worm population nearing the end of the season, then it could be that the outbreak is reduced,” he noted.

“The other factor is the survival rate of the pupae over winter. A cold winter and a lack of snow cover could reduce the number of moths that emerge.”

Risula says that the intelligence being gathered through the monitoring program should soon reveal what producers will be up against.

More information on Berth Armyworm moth counts and risk map is available on the Saskatchewan Agriculture and Food website at www.agr.gov.sk.ca.

For more information, contact:
Dale Risula, Integrated Cropping Management Systems Specialist
Saskatchewan Agriculture and Food
Phone: (306) 694-3714
E-mail: drisula@agr.gov.sk.ca