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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #310974

Title: Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

Author
item Lake, Ellen
item Smith, Melissa
item Dray, F Allen
item Pratt, Paul

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2014
Publication Date: 3/14/2015
Citation: Lake, E.C., Smith, M., Dray Jr, F.A., Pratt, P.D. 2015. Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.. Biological Control. 85:18-24.

Interpretive Summary: Open-field host-specificity testing may provide the most accurate assessment of the ecological host-range of a biological control agent because the agents are able to use all their host-seeking behaviors without being confined to a cage. We conducted a field host-specificity test with experienced and naïve adults of Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae,) a biological control agent of Dioscorea bulbifera L. (Liliales: Dioscoreaceae). We followed field tests with a no-choice laboratory consumption study with the closely related plant species that received test feeding in the field, and an additional field evaluation of spillover risk. The beetles preferred their host plant D. bulbifera to non-target plants in the field. In the laboratory no-choice test, the beetles ate significantly more D. bulbifera and survived longer on this plant than the non-targets. The native D. floridana experience minor feeding damage in the field. At the end of this experiment, L. cheni eggs and/or larvae were present on 83% of D. bulbifera plants but none of the D. floridana plants. We conclude that the Chinese biotype of L. cheni is host-specific to D. bulbifera and does not pose a spillover risk to the native D. floridana.

Technical Abstract: Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide the most accurate assessment of the ecological host-range of an agent. We conducted a two-phase field host-specificity test with experienced and naïve adults of Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae,) a biological control agent of Dioscorea bulbifera L. (Liliales: Dioscoreaceae). We followed field tests with a no-choice laboratory consumption study with the congeneric plant species that received test feeding in the field, and an additional field evaluation of spillover risk. Both experienced and naïve adults preferred D. bulbifera to non-targets in the field. In the laboratory no-choice test, the beetles consumed significantly more D. bulbifera and survived longer on this plant than the non-targets. The native D. floridana experienced minor test feeding in the spillover experiment when surrounded by high populations of L. cheni in the field. At the end of this experiment, L. cheni eggs and/or larvae were present on 83% of D. bulbifera plants but none of the D. floridana plants. We conclude that the Chinese biotype of L. cheni is host-specific to D. bulbifera and does not pose a spillover risk to the native D. floridana.