Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2007
Publication Date: 12/1/2007
Citation: Balciunas, J.K., Korotyaev, B. 2007. Larval densities and field hosts of ceratapion basicorne (coleoptera: apionidae) and its relatives, feeding on thistles in the eastern mediterranean and black sea regions, with an illustrated key to the adults. Environmental Entomology. 36(6):1421-1429.
Interpretive Summary: Yellow starthistle is one of the most widespread and damaging weeds in western United States. A half dozen overseas insects have been approved for release in the United States as biocontrol agents for this weed, and five of these, as well as an unintentionally released fly, have become established in the USA. All of these agents attack the flowers of yellow starthistle. Although seed production is greatly reduced, yellow starthistle continues to spread, and additional agents are needed. We publish illustrations and keys to the weevils whose larvae attack the roots of yellow starthistle in its native range. We also include the results of our field investigations into the density and impact of the most promising of these weevils, Ceratapion basicorne. This weevil is currently being investigated, by ARS scientists and their overseas colleagues, as a potential biological control agent for yellow starthistle. Our results should assist in this research, and allow for another agent to be released to control this widespread pest.
Technical Abstract: Some members of the tribe Carduae are invasive weeds, including yellow starthistle, one of the most important weeds in the western USA. We examined the root crowns and stems of yellow starthistle growing in five countries [Armenia, Republic of Georgia, Greece, Russia, and Turkey] where yellow starthistle is native. In its native range, the root crowns and lower stems of yellow starthistle are frequently attacked by the internal feeding larvae of apionid weevils. When apionid larvae were present, we also examined the relatives of yellow starthistle for apionid larvae. We present illustrations and a key to the adults of the six apionid species that we reared from yellow starthistle and its relatives: Ceratapion basicorne, C. carduorum, C. gibbirostre, C. onopordum, C. orientale, and C. penetrans. The only apionid reared from yellow starthistle was C. basicorne. In Turkey, where we collected most intensively, 66% of the yellow starthistle at 19 sites had larvae of this weevil. This apionid is currently being further researched for its potential as a biocontrol agent for yellow starthistle.