CDFA Plant Health

Curly Top Virus: Biological Control

Biological Control of the Beet Leafhopper

In an effort to reduce pesticide use and develop alternative controls for the beet leafhopper, the BCTVCP contracted the University of California at Riverside (UCR) in 1989, to develop a long-term biological control strategy. The Department of Entomology at UCR proposed foreign exploration for BLH egg parasites and evaluated the effectiveness of Anagrus nigriventris Girault (=A. giraulti Crawford), a native egg parasite of BLH.

A total of 120,000 parasites have been released through 1998. Both UCR and the BCTVCP sampled BLH host plants in release sites to verify establishment of the egg parasite species previously released. Aphelinoidea anatolica has been recovered from more locations than any other parasite species. It was determined to be an ineffective control method due to the long range migratory nature of the BLH and the short range migratory nature of the parasitoids.


In 2014, after a devastating crop loss in 2013, the BCTV Control Board made the decision to fund research with the U.C. Davis Department of Plant Pathology. Researchers have been utilizing PCR methods to test BLH and host plant samples, as well as confirm the curly top virus in symptomatic tomatoes. Research has also been done on a Loop-mediated isothermal amplification (LAMP) assay as a quicker method for screening samples for curly top virus. The BCTVCP hopes to utilize this process by the fall of 2018.