Effect of sediment quality on weevil development and plant resistance

Student: Joanna Watson
Advisor: Ray Newman

This study looked at the effects of the substrate and plant quality on the development of E. Lecontei. Two lakes' sediment, Otter and Ceder, were compared. Milfoil plants were grown in acrylic tubes in laboratory environmental chambers on sediment from various sources. Weevils were reared on either Otter plants grown on Otter or Ceder sediment, or Ceder plants grown on Otter or Ceder sediment. The development of the weevils was then observed and recorded daily. The sediment and plants were analyzed for indicators of quality. Most of this data is not yet available. Analysis of the sediment showed a significant effect on plants for bulk density, percent water, and organic content, plants had a significant effect on sediment NH4+ concentration. The differences in development times for hatch, larval, and pupal stages, along with the total development time, are nonsignificant with respect to plant growth or sediment. The stem diameter was also analyzed and showed no significant differences with respect to plants, sediment or survival of weevils after hatching.