The flea beetle that nourishes mainly on cotyledons causes the greatest damage to seeds during spring season. In North Dakota it has been said that the flea beetles are attacking the growing point of plant and making it to die at the earlier stage.
Due to flea adult feeding it has been recorded that there is reduction in crop stands, plant development, delay ripeness and lower seed yield. The condition that favors flea nourishment is large and warm, sunny, dry and calm conditions. It damages the fields and may result in reseeding the field, underdeveloped plants, rough stands, maturation and harvest problems.
The larvae of flea will feed on the secondary root hairs during summer months, causing yield loss. This feeding cause’s poor seed fill, premature pod drying, shriveled seeds, or pod shattering, and provides an entry point for fungal growth.
The organisms that feed on flea beetles may comprise lacewing larvae (Chrysopa carnea), big-eyed bugs (Geocoris bullatus), the two-lined collops (Collops vittatus) etc
Also parasitic wasps, like Microtonus vittate attacks crucifer flea beetles, but the rate of parasitization is very low. Unluckily the flea beetle populations appear during a fine pane in the spring, and natural enemies usually do not have enough time to harmfully impact flea beetle populations.
It is advisable to use systemic insecticide to prevent the large fall of flea beetle populations.
It is found that around 60-70% of canola seed in North Dakota is using an insecticide-fungicide.
These treatments may offer safety against flea for about 7-14 days after seedling emergence.
Foliar applied insecticides are successful when beetle populations have reached a financial threshold height and treatments are timed accurately.