Chemical Ecology of Microtheca ochroloma

Chemical Ecology of Microtheca ochroloma

Summary

The yellowmargined leaf beetle, Microtheca ochroloma, is a serious foliar pest of high-value cruciferous crops in Florida. Preliminary investigations indicate that the location of oversummer dormancy is correlated to subsequent yellowmargined leaf beetle outbreaks and that host plant finding by the yellowmargined leaf beetle is at least partially chemically mediated.

Objectives/Performance Targets

Objective 1: To demonstrate the extent to which chemical mechanisms (not climatic factors) which cause aestivating beetles to break diapause.
Objective 2: To determine if proximity to old feeding sites determines location of new beetle outbreaks.
Objective 3: To determine what chemical cues (plant- insect and insect-insect) active beetles (both larvae and adults) use to located host plants.

Accomplishments/Milestones

Several things happened during the spring of 2002 which delayed the start of this project. First, I obtained unexpected results from the spring field season. The field experiments were to provide the basis for the SARE funded laboratory work. The delay in processing and interpreting these results led me to put off beginning work on the SARE grant. During the spring, I consulted with additional sources, who advised me to modify my project in order to meet the objectives more effectively. Finally, farmers who reported beetle outbreaks in previous years did not report seeing beetles during the autumn of 2002. Beetles were collected from the field in December 2002 and a small colony is currently being established for experimental purposes. I have incorporated the suggested changes and am waiting for a delivery of equipment within the next weeks to begin this project.

Impacts and Contributions/Outcomes

The results of this research can be used by organic farmers to develop cultural controls for the yellowmargined leaf beetle based on the biology and ecology of the beetle.

Collaborators: