Potential for negative interactions between successful arthropod and weed biological control programs: a case study with Lilioceris species

Authors: Lake, Ellen; TEWKSBURY, LISA - University Of Rhode Island; Smith, Melissa; Dray, F Allen; RUSSELL, ALANA - University Of Rhode Island; Madeira, Paul; Rayamajhi, Min; CASAGRANDE, RICHARD - University Of Rhode Island

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2020
Publication Date: 2/7/2020
Citation: Lake, E.C., Tewksbury, L., Smith, M., Dray Jr, F.A., Russell, A., Madeira, P.T., Rayamajhi, M.B., Casagrande, R. 2020. Potential for negative interactions between successful arthropod and weed biological control programs: a case study with Lilioceris species. Biological Control. 144. https://doi.org/10.1016/j.biocontrol.2020.104218.
DOI: https://doi.org/10.1016/j.biocontrol.2020.104218

Interpretive Summary: Successful biological control programs can effectively manage insect and weed pests over large areas. Management of these pests using biological control can improve ecosystem services, reduce management costs, and decrease the widespread use of pesticides. However, attack by resident parasitoids or predators can prevent biological control agents from establishing or limit their efficacy. In this study, we assessed the potential for biological control agents of the pest Lilioceris lilii, the lily leaf beetle, to attack L. cheni, a weed biological control agent for Dioscorea bulbifera, air potato. The suite of parasitoid biological control agents and L. cheni are both contributing to the successful management of their respective targets. Thus, negative interactions between these species could potentially disrupt two effective biological control programs if range overlap occurs. Choice and no-choice tests were conducted with all three parasitoid species and the target and non-target beetles. We also constructed a phylogenetic tree to assess their relatedness. The parasitoids displayed a clear preference for their host, L. lilii, and did not successfully parasitize L. cheni. Although interference between arthropod and weed biological control programs is not likely to be a common occurrence, practitioners in both subdisciplines should be aware of this possibility as new agents are developed.

Technical Abstract: Successful biological control programs can have landscape-level effects on the management of intractable arthropod pests and weeds, improving ecosystem services and reducing both management costs and the widespread use of pesticides. However, biotic resistance can prevent biological control agents from establishing or limit their efficacy. We assessed the potential for biological control agents of the pest Lilioceris lilii, the lily leaf beetle, to attack L. cheni, a weed biological control agent for Dioscorea bulbifera, air potato. Both the suite of parasitoid biological control agents and L. cheni are contributing to the successful management of their respective targets. Thus, negative interactions between these species could potentially disrupt two effective biological control programs if range overlap occurs. Choice and no-choice tests were conducted with all three parasitoid species and the target and non-target beetles, and a phylogenetic tree was constructed to assess their relatedness. The parasitoids displayed a clear preference for their host, L. lilii, and did not successfully parasitize L. cheni. Although interference between arthropod and weed biological control programs is not likely to be a common occurrence, practitioners in both subdisciplines should be cognizant of this possibility as new agents are developed.