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ARS Home » Southeast Area » Fort Lauderdale, Florida » Invasive Plant Research Laboratory » Research » Publications at this Location » Publication #310981

Research Project: DEVELOPMENT & EVALUATION OF BIOLOGICAL CONTROL AGENTS FOR INVASIVE SPECIES THREATENING THE EVERGLADES & OTHER NATURAL AND MANANGED SYSTEMS

Location: Invasive Plant Research Laboratory

Title: Mile-a-minute weed (Persicaria perfoliata) and weevil (Rhinoncomimus latipes) response to varying moisture and temperature conditions

Author
item Berg, Scott - University Of Delaware
item Hough-goldstein, Judith - University Of Delaware
item Lake, Ellen
item D'amico, Vincent - Us Forest Service (FS)

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2015
Publication Date: 4/1/2015
Citation: Berg, S.H., Hough-Goldstein, J., Lake, E.C., D'Amico, V. 2015. Mile-a-minute weed (Persicaria perfoliata) and weevil (Rhinoncomimus latipes) response to varying moisture and temperature conditions. Biological Control. 83:68-74.

Interpretive Summary: Greenhouse experiments were conducted test how herbivory and water stress affected the growth and reproduction of the invasive plant mile-a-minute weed (Persicaria perfoliata (L.) H. Gross). Both moisture limitation and feeding by the mile-a-minute weevil Rhinoncomimus latipes (Coleoptera: Curculionidae) reduced the number of seeds produced. Seed weight was reduced by both moisture limitation and weevil herbivory the second year, and seed viability was reduced by herbivory both years. Plant biomass was lower both years under conditions of water limitation, with an additional effect of herbivory the second year. These results are consistent with field observations that suggest that years of high rainfall allow resurgence of mile-a-minute weed populations that were previously suppressed by the weevil. An additional experiment in environmental chambers assessed the interaction between weed and weevil at two different temperatures. Here, mile-a-minute plants only died at the higher temperature with weevils present, suggesting that herbivory has a greater negative effect on mile-a-minute weed under warm conditions. Additional studies on temperature effects are needed for a more complete understanding of interactions between the weed and weevil under different abiotic conditions.

Technical Abstract: The combined effects of herbivory and water stress on growth and reproduction of mile-a-minute weed (Persicaria perfoliata (L.) H. Gross) were investigated in greenhouse trials over two years, with well-watered or water-limited plants either exposed or not exposed to herbivory by the mile-a-minute weevil (Curculionidae: Rhinoncomimus latipes). Both moisture limitation and weevil herbivory had significant effects on the numbers of seeds produced by P. perfoliata both years, with the fewest seeds produced when both factors were present. Seed weight was reduced by both moisture limitation and weevil herbivory the second year, and seed viability was reduced by herbivory both years. Plant biomass was lower both years under conditions of water limitation, with an additional effect of herbivory the second year. Well-watered plants the second year also produced substantially more weevils than water-limited plants by the end of the season. Results are consistent with field observations suggesting that years of high rainfall allow resurgence of P. perfoliata plant populations that were previously suppressed by R. latipes. An additional incubator trial assessed the interaction between weed and weevil at two different temperatures. Here, plant mortality occurred only at the higher temperature with weevil herbivory, suggesting that herbivory has a greater negative effect on P. perfoliata under warm conditions. Additional studies on temperature effects are needed for a more complete understanding of interactions between P. perfoliata and R. latipes under different abiotic conditions.