Predicted Alfalfa Weevil Development

Ross Weiss, Owen Olfert, David Giffen and Erl Svendsen
Week 2

Degree-day maps of base 9°C are now being produced by Soroka, Olfert, and Giffen (2015) using the Harcourt/North Dakota models predicting the development of Alfalfa weevil (Hypera postica) across the Canadian prairies.  The model output is mapped below to help alfalfa growers time their in-field monitoring.

Watch this map for the predicted occurrence of second-instar alfalfa weevil larvae.  The economic threshold for alfalfa weevil targets third- and fourth-instar larvae but, in the event that second-instar larval densities exceed either the forage or seed production thresholds, control is appropriate to prevent third-instar peaks.

The model predicted egg hatch began the week of May 14, 2015, in the Brooks AB area (note area below shaded brown corresponding to 165 DD base 9°C).  Growers in that area should be monitoring for alfalfa weevil this week.

Please contact for information pertaining to this map.

Wind Trajectories

Ross Weiss, Owen Olfert, Serge Trudel and prairiepest_admin
Week 2
   Wind trajectories Related to Diamondback Moth (DBM) and Aster Leafhopper Introductions to the Canadian
Prairies in 2015

  Potential wind events capable of carrying insect
pests from source areas in the USA can be identified by following trajectories
for air parcels through time. 
High altitude air masses,
originating from southern locations, frequently move northerly to Canadian
destinations. Insect pest species such as Diamondback moth and Aster
leafhoppers, traditionally unable to overwinter above the 49th parallel, can
utilize these air masses in the spring to move north from Mexico and the United
States (southern or Pacific northwest). 

Wind trajectory data processing by AAFC-Saskatoon Staff began in April.  Reverse
 track air masses arriving across the prairies back to
their point of origin.  Forward Trajectories predict
favourable winds expected to arrive across the Canadian Prairies.  
    Updated: May 13, 2015
    1. Reverse trajectories (RT) – During April and early
May, reverse trajectories winds were originating over the Pacific Ocean and
tracking in a west to east direction across North America.  Since May 8th
most are now originating over the Arctic.
    a. Pacific Northwest (PNW) –
Nothing to report.
    b. Mexico and southwest USA (SW)
– Nothing to report.
    2. Forward trajectories (FT)
    There are
a number of forward trajectories from southern USA and Mexico predicted to
cross the prairies over the next five days. The Imperial Valley and Mexicali
FTs are predicted to cross southern Saskatchewan and Manitoba.  The Santa
Maria FT is predicted to cross into central Alberta. 

Seasonal canola scouting chart

Jennifer Otani
Week 2
Field scouting is critical because it
enables the identification of potential risks to crops.  Canola production
systems across the Canadian prairies will suffer insect pest outbreaks.
 However, the identification of these insect pests PLUS the application of
established monitoring methods will enable growers to make informed pest
management decisions.
This year we offer a generalized canola
scouting chart to aid in-field scouting on the Canadian prairies. Two versions
are offered below

the first
hyperlinks to help growers learn more about some of our insect pests and how to
monitor while the second version may be easier to view or print.  

Whenever possible, monitor and compare to
established economic thresholds so pollinators and beneficial arthropods are
preserved.  Economic thresholds, by definition, can help growers avoid crop losses due to an insect pest
Good luck with the growing season!


Insect of the Week – Crucifer and Striped flea beetles

Jennifer Otani
Week 2

See this week’s Insect of the Week for descriptions and pictures of the crucifer and striped flea beetles (Phyllotreta cruciferae and P. striolata) from the new Field Crop and Forage Pests and their Natural Enemies in Western Canada – Identification and Management Field Guide