Google Translate Disclaimer

A number of pages on the Government of Saskatchewan's website have been professionally translated in French. These translations are identified by a yellow box in the right or left rail that resembles the link below. The home page for French-language content on this site can be found at:

Renseignements en Français

Where an official translation is not available, Google™ Translate can be used. Google™ Translate is a free online language translation service that can translate text and web pages into different languages. Translations are made available to increase access to Government of Saskatchewan content for populations whose first language is not English.

Software-based translations do not approach the fluency of a native speaker or possess the skill of a professional translator. The translation should not be considered exact, and may include incorrect or offensive language. The Government of Saskatchewan does not warrant the accuracy, reliability or timeliness of any information translated by this system. Some files or items cannot be translated, including graphs, photos and other file formats such as portable document formats (PDFs).

Any person or entities that rely on information obtained from the system does so at his or her own risk. Government of Saskatchewan is not responsible for any damage or issues that may possibly result from using translated website content. If you have any questions about Google™ Translate, please visit: Google™ Translate FAQs.

Scouting for Flea Beetles and Assessing Damage

By Cory Jacob, PAg, Provincial Specialist, Oilseed Crops, Regina

June 2021

Flea beetle damage on canola
Flea beetle feeding on canola seedling.

Flea beetles are a common insect pest for canola and mustard producers across the prairies. The two main species are the striped flea beetle and the crucifer flea beetle. Northern regions are dominated by striped flea beetles that prefer cooler, moist conditions, while crucifer flea beetles are dominant in southern regions of the province.

When scouting fields for flea beetle damage and making a decision to spray or not, a producer needs to consider a number of things:

  • Start at the field edge –flea beetles will move into a field and damage on the headlands does not necessarily mean there’s damage further into the field.
  • Spray thresholds – the action threshold is a pest density or damage amount at which management action should be taken to prevent increasing pest density or damage from reaching the economic threshold. The action threshold is 25 per cent leaf area loss for flea beetles. Leaf area loss can quickly escalate to 50 per cent, which is the economic threshold. The economic threshold is an insect population or level of crop damage at which the value of the crop destroyed exceeds controlling the pest.
  • Leaf area loss and stem damage – check plants in a number of areas in the field and move in from the headlands. Look at the newest leaves as flea beetles prefer to feed on them. Stem damage can cause more damage than leaf damage. Windy or cool weather drives the insect to undersides of leaves and stems and more stem feeding may be seen. Stem feeding can be fatal to a canola seedling if the stem is broken, versus feeding on a leaf.
  • Assess the feeding activity – are flea beetles still present in the field and actively feeding? If they seem to be moving slow they may have ingested seed treatment and are no longer feeding. Time of day and weather influences activity too as rainy and cool weather will slow down feeding activity.
  • Crop stage – at the 4-leaf stage the crop has enough plant material to withstand flea beetle feeding.
  • Plant stand – if there are just four plants per square foot, producers can’t afford to lose plants and they may want to take action at 25 per cent leaf area loss. However, when plant counts are in the recommended range of five to eight plants per square foot, producers can afford to lose a plant or two without yield loss.
  • Seed treatment needs to be ingested by the flea beetles to be effective. Producers should be aware of the seed treatment on their canola seed as certain products will also be effective against cut worms.
  • Use only pesticides registered for flea beetle control.
  • Flea beetles can develop resistance to insecticides. Producers should be spraying an insecticide to control flea beetle damage when it is justified.

We need your feedback to improve Help us improve