University of California

Two new seed head flies attack yellow starthistle


Joe Balciunas
Baldo Villegas

Authors Affiliations

J. Balciunas is Research Entomologist and Yellow Starthistle Biocontrol Project Leader at the Exotic & Invasive Weed Research Unit, USDA-ARS Western Regional Research Center, Albany; and a member of the UC Berkeley Center for Biological Control; B. Villegas is Associate Environmental Research Scientist, California Department of Food and Agriculture, Biological Control Program, Sacramento.

Publication Information

Hilgardia 53(2):8-11. DOI:10.3733/ca.v053n02p8. March 1999.

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Six species of overseas insects have been approved for release as biological control agents of yellow starthistle, California's most pervasive weed. Previously, four biocontrol insects were known to be established in California; we now confirm the establishment of the peacock fly, as well as the accidentally introduced false peacock fly. Remarkably, the false peacock fly is significantly more widespread and more effective against yellow starthistle than the peacock fly — or any other biocontrol insect to date. However, since the false peacock fly is not an approved agent, we will await completion of our ongoing field and laboratory assessments of this fly's safety to crops and native plants before recommending use of this promising fly as a biological control agent.


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Balciunas J, Villegas B. 1999. Two new seed head flies attack yellow starthistle. Hilgardia 53(2):8-11. DOI:10.3733/ca.v053n02p8
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