Insect of the Week (May 28, 2018) - Flea Beetles

This week's Insect of the Week is the Flea Beetle (Phyllotreta species). This group of beetles is typically oval and 2-3 mm long.  In canola, the most common flea beetles are either bluish black (crucifer flea beetle or Phyllotreta cruciferae) or black with two wavy yellow lines running down the length of its back (striped flea beetle or Phyllotreta striolata). They overwinter as adults under plant material along field margins and females lay eggs in the soil near the host plants. 

Striped and crucifer flea beetles feed on canola, mustard and related cruciferous plants and weeds. Their damage results in a shot-hole appearance in cotyledon leaves. They also feed on stems under windy or damp conditions, causing wilting or breakage. Remember, the Action Threshold for flea beetles on canola is when 25% of cotyledon leaf area is consumed. 

For more information on flea beetles, refer to the Insect of the Week page!

Crucifer flea beetle and damage
Photo: AAFC

Flea beetle damage on cotyledon
Photo: Mike Dolinski, MikeDolinski@hotmail.com