Effects of resistance discovered in seedlings can thereby be compared to the potential for resistance in other stages of tree grown from similar germplasm. Roots from plant species entirely unrelated to citrus can also be tested for their effect on growth and survival of Diaprepes larvae. Change in larval weight after feeding 32 days on 5 g milled roots added to 100 ml diet. 2Cups with diet only contained no ground roots. The diet-incorporation assay will also be very useful for further studies on chemical or biological constituents of roots that may be responsible for inhibited larval growth.
Present results indicate a molecular or microbial source of larval growth inhibition.
This low requisite concentration of roots will reduce the time and sample size required to identify active molecules or microbes. Our discovery of growth-inhibiting activity in G. pentaphylla and the development of a bioassay to examine that activity should contribute to finding or developing a rootstock with resistance to the weevil. The authors thank Thomas Moyer, Charles Spriggs, and Karin Crosby for their excellent technical assistance on this project, and Stephen Lapointe for writing the Resumen. Funds for this project were made available from the Citrus Production Research Marketing Order by the Division of Marketing and Development, Florida Department of Agriculture and Consumer Services. References Beavers, J. B., and D. J. Hutchison.