When the conditions are right, flea beetles move quickly and devastate quickly. The bugs are the most chronically damaging insect pest of canola in Western Canada. They inflict the most damage on canola at the seedling stage, inhibiting proper plant growth and delaying maturity. They will feed on more mature plants, but canola at later stages of development is much less susceptible to damage due to its size. The pests move and feed best in warm, dry, calm conditions over 14 degrees celsius.
Over the past few weeks flea beetles have started to emerge, and while the cool, wet conditions across the prairies have restricted the movement of these pests, it has also kept farmers from seeding. The problem comes with the fact that when farmers do get their canola seeded and plants do start to come up, conditions could be just right for the flea beetle to inflict maximum damage.
Flea beetles typically overwinter in field perimeters and shelter belts around or near fields. Accurate and timely field scouting starting in these areas is critical for a farmer to establish if the flea beetle is present, and if it is, to establish what steps they should take to keep them from spreading. If the pest is present and feeding, assessing damage and potential control measures is next. Control measures should be taken if the nominal economic threshold ( an average defoliation level of 25% or more of the seedling leaf area ) is exceeded and flea beetles are present.
Dr Julie Soroka is a research scientist with Agriculture and Agri-Food Canada based out of the Saskatoon Research Centre in Saskatoon, Saskatchewan. She is an expert in all aspects of flea beetle activity. I spoke with her about the pest, the damage it can do, how and when to look for it, and what this year may bring for activity.
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