DEVELOPMENT OF A NEW BIOLOGICAL CONTROL AGENT FOR YELLOW STARTHISTLE
Exotic and Invasive Weeds Research
2012 Annual Report
1a.Objectives (from AD-416):
Test host plant specificity of Larinus filiformis in quarantine laboratory and field experiments in order to submit a petition to USDA-APHIS requesting permission to release it as a biological control agent of yellow starthistle.
1b.Approach (from AD-416):
We will conduct choice and no-choice oviposition experiments on the flower head weevil Larinus filiformis in our quarantine laboratory and conduct a field host specificity evaluation of L. filiformis in its native range in Turkey. If it is sufficiently host-specific, we will submit a petition to USDA-APHIS to obtain a permit to release the weevil.
This research supported Objectives 2 and 3 of the parent project, by testing new biological control agents for invasive weeds. Over the life of this project, the weevil, Larinus filiformis, was received in our quarantine laboratory for host specificity evaluation as a prospective agent for yellow starthistle. A field experiment was conducted in Igdir, Turkey, where we released Larinus filiformis to evaluate its potential risk to nontarget plant species. Results are incomplete because we are still rearing out adult insects, but so far Larinus filiformis has attacked yellow star thistle, but none of the nontarget plants.