I certify that I have read this study and that in 

 my opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, 

 as a dissertation for the degree of Doctor of Philosophy. 



Donald W. Hall, Chairman 

 Professor of Entomology and 

 Nematology 



I certify that I have read this study and that in 

 my opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, 

 as a dissertation for the degree of Doctor of Philosophy. 



CliiJx)rd S. Lofgr^f Co-Chairman 

 Professor of Entomology and 

 Nematology 



I certify that I have read this study and that in 

 my opinion it conforms to acceptable standards of scholarly 

 presentation and is fully adequate, in scope and quality, 

 as a dissertation for the degree of Doctor of Philosophy. 



Robert C. Wilkinson, Jr. 

 Professor of Entomology and 

 Nematology 



