Crop & Pest Report

Accessibility


| Share

Canola Flea Beetles Emerging (06/01/17)

Crucifer and stripped flea beetles are emerging now and can be found in the NE, NC and SW areas of canola in ND.

Canola Flea Beetles Emerging

Crucifer and stripped flea beetles are emerging now and can be found in the NE, NC and SW areas of canola in ND. Adult flea beetles feed on cotyledons and first true leaves in the spring. The leaf tissue is devoured by adult flea beetles producing a shallow divots or shot-holes with necrosis. In the more northern tier of North Dakota, flea beetle feeding activity has been low due to the near freezing low temperatures and wet weather the past two weeks. Flea beetles are most active feeding when temperatures are warm, at least above 57 F, and sunny! However, in the SW, where it is dry, flea beetles have been causing feeding injury on foliage, above the action threshold level of 25% foliar defoliation. In SW ND, a foliar insecticide application on top of the insecticide seed treatments was needed to suppress flea beetle damage in some canola fields. Insecticide toxicity residue of insecticide seed treatments start to decline after 21 days of planting and only provide a short-window of protection against flea beetles when the canola crop is in the seedling to 4-leaf crop stage.

It is important scout canola fields for flea beetle feeding activity until the end of June. During hot, dry weather, flea beetles populations can increase rapidly, and they can quickly move into canola fields in large numbers.

knodel.5

Janet J. Knodel                                      Travis J. Prochaska                                     Lesley Lubenow

Extension Entomologist                     Area Ext Specialist, NCREC                      Area Ext. Specialist, LREC

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.