The cabbage maggot (Delia radicum) is the larvae stage of the cabbage root fly which can cause severe damage to all Brassica crops. The adult cabbage maggot is a fly that is about half the size of a house fly and is grey in colour.
Flea beetles are a common crop pest of crucifers in Ontario and overwinter as adults near the soil surface in debris and stubble from the previous crop. They typically become active with the first extended period of warm weather in the early spring as the leaf litter begins to thaw. The beetles feed on weeds throughout the field and have the ability to fly on calm days and will attack brassica seedlings as they emerge or transplants as they are planted.
Females will begin laying eggs in soil for about 30 days. Flea beetle larvae will hatch from eggs 12 days later and feed on the root hairs and taproots of seedlings. Left unchecked, adults will feed on leaves of transplants and the larvae will burrowing into the plant near the juncture of the root and stem. Continue reading Preventing Yield Loss from Flea Beetles→
By Travis Cranmer, Vegetable Crops Specialist
First appeared in ONvegetables in The Grower, April 2017.
Clubroot, caused by the soil-borne pathogen Plasmodiophora brassicae can cause yellowing, stunting, wilting and club-like roots on susceptible Brassica species including broccoli, cabbage, canola and cauliflower. Clubroot causes an estimated yield loss of 10-15% in Brassica crops worldwide and in severely infested fields a 30-100% yield loss can occur. There are different races of clubroot known as pathotypes and the resistance of many cultivars is pathotype dependent.
Reposted from ONvegetables.com orginally posted on 15 May 2013. Flea beetle activity in brassica crops has been reported.
What species of flea beetles affect crucifer crops in Ontario?
Two species of flea beetles that commonly feed on brassica crops in Ontario are the crucifer flea beetle (Phyllotreta cruciferae) and striped flea beetle (Phyllotreta striolata). There are reports that the crucifer flea beetle is more common in Ontario than the striped flea beetle.