8 ILLINOIS BIOLOGICAL MONOGRAPHS [240 



The investigation of the immature stages of insects was to a great 

 extent neglected by entomologists until about the beginning of the twen- 

 tieth century. There has been some previous work done, however, upon 

 the immature stages of the Coccinellidae. The works of L. Ganglbauer 

 (1899), Dimmock (1906), Palmer (1914), and Boving (1917) are valuable 

 to one pursuing a study of the immature stages of these beetles. 



I am greatly indebted to Dr. A. D. MacGillivray, under whose super- 

 vision this work was carried on, for the interest he has shown at all times, 

 for the use of specimens from his collection, and for the privilege of using 

 the morphological nomenclature which he has devised. I am likewise 

 indebted to Professor S. A. Forbes for the use of material belonging to the 

 Illinois State Natural History Survey, and to Professor J. G. Needham 

 for the loan of material from Cornell University. 



