Evaluation of Flea Beetle Phenology and Damage to Carrot Production
Evaluation of Flea Beetle Phenology and Damage to Carrot Production
COLLABORATORS: Joe Nunez, Plant Pathologist and Vegetable Crop Advisor, UCCE Kern Co.
In 2012-2013 carrot growers in the lower San Joaquin and Antelope Valleys have been reporting an unknown injury to the taproot of carrots. Superficially the damage looks like cavity spot (Pythium sp.), a fungal disease that causes depressed lesions oriented across the taproot. However, upon closer inspection it was found to feeding damage from an insect that was coupled with secondary infections that enhanced the injury's appearance as cavity spot. This damage is now attributed to feeding from potato flea beetle larvae.
The principal concern with cavity spot and damage by the potato flea beetle larvae is that they are easily confused with each other. This may trigger the use of fungicides for a problem caused by insects, or vice versa. The result is a lack of control, a waste of money, and continued economic damage to the crop. At this point we are still uncertain about the relative prevalence of flea beetle injury compared to cavity spot.
Websites
Potato Flea Beetle Documents