Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/14/2005
Publication Date: 11/6/2005
Citation: Smith, L., Christofaro, M., Hayat, R., Tronci, C., Tozlu, G. 2005. Evaluation of host plant specificity of ceratapion basicorne (coleoptera: apionidae), a prospective biological control agent of yellow starthistle (centaurea solstitialis). Meeting Proceedings of the Entomological Society of America, Ft. Lauderdale, FL, Nov. 6-10, 2005. p.132.
Interpretive Summary: Yellow starthistle is an important alien weed that has invaded over 20 million acres in the western U.S. It is a spiny plant that interferes with grazing livestock and outdoors recreation, it is fatally poisonous to horses, and it outcompetes desirable vegetation. Previously introduced biological control agents became established but are not providing sufficient control. We have evaluated a prospective new agent of this weed and have requested permission to introduce it. This new biological control agent should help reduce the populations of these two weeds to innocuous levels over extensive regions. Successful biological control will provide self-perpetuating long-term management of these weeds, reduce the need to apply pesticides, and increase the productivity and utility of millions of acres in the western U.S.
Technical Abstract: We submitted a petition to the APHIS Technical Advisory Group (TAG) requesting permission to release the weevil, Ceratapion basicorne, whose larvae develop inside the root crown of yellow starthistle (Centaurea solstitialis, YST) rosettes in the early spring. The insect has a wide geographic distribution in Eurasia and infests up to 100% of YST at sites in Turkey. A colony of C. basicorne was established in the quarantine laboratory in Albany, CA. No-choice and choice laboratory experiments showed that the insect is specific to a few species in the genus Centaurea. We found no risk to native North American plant species, including those in the most closely related taxa: Cirsium, Saussurea and Plectocephalus (=Centaurea in part). Three years of field experiments in Turkey confirmed that the insect does not attack safflower (Carthamus tinctorius), which is in the same subtribe (Centaureinae) as the target weed. We are recommending the insect for introduction to the U.S.