11 



ARTICLE I. ON NEW AND LITTLE KNOWN CORN INSECTS. 



In arranging for this report, our notes of the season on insects 

 injurious to corn, I have assumed that in the present state of our 

 knowledge, nothing could be reckoned really insignificant which 

 either now affected or threatened to affect in future, a crop so im- 

 portant as this to the prosperity of the State. The balance of in- 

 sect life in any cultivated region, is so unstable in character, sub- 

 ject to changes dependent upon differences of season and agricul- 

 tural practice, and upon a variety of other causes not well under- 

 stood, that it is possible that the most trivial species affecting a 

 crop, may rapidly rise to be one of the most destructive, especially 

 if it be its normal habit to produce several successive broods in a 

 season. In such an event the importance of accurate knowledge of 

 the uprising species will be readily appreciated, and our acquain- 

 tance with the life history of all should be such that we may be 

 able readily and correctly to divide them into the groups of dan- 

 gerous and indifferent species. Our observations of the year, have 

 consequently not been confined exclusively to the major insects in- 

 jurious to corn, but have covered the minor species also, with a 

 view to thus laying the foundations for a complete knowledge of the 

 subject of insect injuries to this crop in Illinois; and the following 

 paper is to be regarded as preliminary to an elaborate and extensive 

 treatment of the subject in a future report. 



