BIENNIAL REPORT 



ILLINOIS STATE LABORATORY 



NATURAL HISTORY. 



To the Triistex'S of the University of Illinois. 



Gentlemen : In pursuance of your general instructions as 

 contained in your Proceedings for 1892 (June meeting), I 

 submit the following report of operations of the State Laboratory 

 of Natural History for the past two years. 



These operations have been connected almost wholly with 

 the work of the State Entomologist or with that of the Biological 

 Station. As the State Entomologist's operations will be reported, 

 under the law, to the Governor previous to the next session of 

 the legislature, I will only say with regard to them here that 

 they have been directed mainly to the study of the life histories of 

 some of the insects injurious to corn, to an examination of the 

 shade trees and other ornamental vegetation of several of the 

 larger towns of central Illinois, and to work on the San Jose 

 scale, distributed throughout the State. 



Further investigation of the corn insects was undertaken 

 with a view to preparing for my next biennial report a second 

 instalment of a monograph upon that subject. The study of 

 the insects injurious to shade trees is the beginning of what I 

 intend to make an exhaustive survey of that topic in this State ; 

 and the work on the San Jose scale has taken the form of a 

 further examination of suspected premises with a view to the 

 possible occurrence of hitherto undetected colonies of that insect 

 in the State, a very thorough and careful spraying with insecti- 

 cide solution of premises known to harbor the scale, the intro- 

 duction of two fungus parasites of the scale obtained l)y me on 



