Development of Biological Control for Alliaria petiolata (Garlic Mustard)
Abstract
Alliaria petiolata, garlic mustard, a biennial plant of European origin accidentally introduced to North America, has spread throughout much of eastern and midwestern North America and is now recorded in 34 states and 4 Canadian provinces. Invasion of natural forest communities by garlic mustard is considered a serious problem because it is believed to displace indigenous herbaceous flora and fauna. Physical, mechanical, and chemical means of management of garlic mustard have failed to achieve long-term control. The development of biological control appears the only viable option for long-term ecologically sound management of the species. Six different beetle species (Chrysomelidae and Curculionidae) were evaluated for their impact and host specificity in Europe. A seed feeding weevil, Ceutorhynchus theonae, was too rare, and rearing under quarantine conditions in Switzerland too difficult, to pursue investigations of this insect. A second species, the flea beetle Phyliotreta ochripes, showed promise based on multiple generations and significant impact on plant performance. However, the species attacked a number of other plant species, even in multiple-choice feeding tests, and therefore is not considered sufficiently specific to be considered further as a biological control agent. Detailed investigations focused on the seed-feeding weevil Ceutorhynchus constrictus, two stem mining weevils, C. alliariae and C. roberti, and a stem and root-crown feeding weevil C. scrobicollis. The seed feeder was widely distributed in Europe but attack rates remained fairly low throughout the investigative period. This may be, in part, explained by significant mortality through attack by parasitic natural enemies. Experiments showed that the two stem--mining weevils are reproductively isolated species that can co-exist in the same ecological niche.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2003
- Accession Number
- ADA477109
Entities
People
- Bernd Blossey
- Esther Gerber
- Harriet Hinz
- Victoria Nuzzo
Organizations
- Cornell University Department of Natural Resources