Scout for Flea Beetles Feeding on Canola Pods | Northern Canola Growers Association

The summer population of flea beetles is emerging, so now is a good time to check your canola fields for any pod feeding. Moderate pod feeding was reported on the field edges in a canola field near Langdon, northeast North Dakota. Based on research conducted at Agriculture and Agri-Food Canada in Saskatoon, Canada found that late summer feeding on canola pods by flea beetles is rarely economical. “Flea beetle feeding that occurs when seeds in lower pods of canola are at the green stage or beyond is unlikely to affect seed yields regardless of the infestation rate of flea beetles. Even when seeds are translucent to green, numbers higher than 100 flea beetles per plant, and for some cultivars higher than 350 per plant, may be necessary to cause significant yield reductions.” (Source: J. Gavloski, Manitoba Crop Pest Update #13, August 14, 2019)
Flea beetle feeding injury on pods is usually most significant on lateplanted canola and on the upper pods. Fortunately, the lower pods of canola are the primary pods that provide most of the canola yield. However, flea beetle feeding injury on pods can result in poor seed fill, premature pod drying, or pod shattering. If the canola is mature, past the 5.2 growth stages (when seeds in lower pods have turned translucent to green), then yield will be less impacted by flea beetle feeding. In a flea beetle trapping study of freshly swathed canola, the number of flea beetles per trap decreased dramatically after 7-days of drying in swaths. Flea beetles are mobile insects and fly around to find ‘greener’ canola fields (late-planted) or other cruciferous host plants like backyard garden vegetables or flowers for summer feeding.
Insecticides registered for flea beetle control with a short, 7-day Pre-Harvest Interval (PHI) include: Delta Gold
(deltamethrin), Warrior II and generics (lambda-cyhalothrin) and Mustang Maxx (zeta-cypermethrin).

https://www.ndsu.edu/agriculture/sites/default/files/2023-08/14%20CPR%20August%2010%202023%20Final_1.pdf?fbclid=IwAR2hxzwk2msgREZ0CsJ6KzqdcEzpffPLMQ5XdGykN8IdxMIFauKGs7s4c1s