BIENNIAL REPORT 
ILLINOIS STATE LABORATORY 
OF 
NATURAL HISTORY. 
To the Trustees of the University of Illinois. 
GENTLEMEN: In pursuance of your general instructions as 
contained in your Proceedings for 1892 (June meeting), | 
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 witli 
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 José 
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 José 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 by me on 
as 
