Evaluation of host range and larval feeding impact of Chrysolina aurichalcea asclepiadis (Villa): considerations for biological control of Vincetoxicum in North America.
A biological control program has been initiated against European swallow-worts Vincetoxicum nigrum (L.) Moench. and V. rossicum (Kleopow) Barbar., which are invasive in North America. A population of the leaf beetle Chrysolina aurichalcea asclepiadis (Villa) originating from the western  Alps has been under evaluation as a part of this program. The preliminary host range of C. a. asclepiadis was determined among 37 potential host plants. In addition, a prerelease impact study was conducted to determine the effect of larval feeding on the performance of V. nigrum. Under no-choice  conditions beetle larvae completed development on nine plant species within the genera Artemisia and Tanacetum (Asteraceae) and Asclepias and Vincetoxicum (Apocynaceae). The host range of adults is broader than larvae (13 plant species within five genera received sustained feeding). Three  of the six nontarget species supporting larval development are native to North America, however in separate oviposition tests, female beetles failed to produce eggs when confined to these hosts. In multiple-choice tests, neither larvae nor adults preferred Vincetoxicum spp. to nontarget species.  Larval damage by C. a. asclepiadis at densities at and above five larvae per plant substantially reduced growth, biomass, and delayed reproduction of V. nigrum. However, this population of C. a. asclepiadis is polyphagous and unsuitable for biological control of Vincetoxicum because of potential  risk of attack to Asclepias tuberosa L. and native North American Asteraceae, particularly Artemisia.
Department of Plant Sciences and Entomology, University of Rhode Island, Kingston, RI 02881, USA. aaron.s.weed@dartmouth.edu
Aaron S
AS
Weed
Richard A
RA
Casagrande
D000818:Animals; D029062:Apocynaceae / Q000254:growth & development*; D019659:Asteraceae / Q000254:growth & development*; D001517:Coleoptera / Q000254:growth & development / Q000502:physiology*; D005260:Female; D005518:Food Preferences; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008297:Male; D009656:North America; D010058:Oviposition; D010572:Pest Control, Biological / Q000379:methods*; D013557:Switzerland