How to Manage Pests

Pests in Gardens and Landscapes

Beet leafhopper transmitted virescence agent (BLTVA) on carrots

Symptoms of beet leafhopper transmitted virescence agent include reddish purple leaves. Infected plants often bolt prematurely. Flower parts are malformed, petals that would normally be white are green, and the flowers proliferate to form multiple, compound, leafy umbels. Diseased plants have woody roots with an excessive number of lateral rootlets.


BLTVA is a phytoplasmalike organism transmitted by the beet leafhopper, Circulifer tenellus. The level of infection is dependent on the population of vectors. Disease incidence may be greater if carrots are planted near areas where weeds and other plants provide a reservoir for the organisms and their vectors. Destroy infected plants. Remove weeds or other plants that may be hosts of the virus or of leafhoppers.

Lateral rootlets on BLTVA infected plant

Lateral rootlets on BLTVA infected plant

Statewide IPM Program, Agriculture and Natural Resources, University of California
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