UNITED STATES DEPARTMENT OF AGRICULTURE 



| BULLETIN No. 1016 { 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



SLHr^Lru 



Washington, D. C. 



PROFESSIONAL PAPER 



January 31, 1922 



BIONOMICS OF THE CHINCH BUG. 



By Philip Luginbiix, Entomological Assistant, Cereal and Forage Insect 



Investigations. 



CONTENTS. 



Page. 



Introduction 1 



Seasonal history in South Carolina — 2 



Behavior 3 



Mating . — 3 



Life history of the chinch bug 4 



Description of the egg and nymphal 



instars 



Sexual differences among adults 



A. parasite of the adult 



Page. 



10 

 10 

 14 



INTRODUCTION. 



During several years past the biology of the chinch bug (Blissus 

 leucopterus Say) has been studied in South Carolina with a view to 

 the control of the insect in that region. It is a pest of considerable 

 importance, especially in some of the northern counties of the State. 

 Many planters in this region will plant no grain, giving as a reason 

 that attempts to grow grain result in producing chinch bugs, and as 

 a consequence they are unable to make a corn crop. Coincident with 

 the conduct of field investigations, some time was devoted to a study 

 of the insect in the laboratory at Columbia, and although this work 

 is not complete, certain novel facts regarding the life history of the 

 pest have been learned which make it advisable to publish imme- 

 diately the information thus obtained. Wherever the chinch bug has 

 been treated in the literature, it has always been represented as pass- 

 ing through five instars in its development. By means of the experi- 

 ments conducted at Columbia, S. C, it has been shown that in this 

 locality the insect has six instars, instead of five, exclusive of the egg 

 stage, viz, five immature stages, the sixth being the adult stage. The 

 figures of the stages of this insect given by C. V. Riley, which have 

 been used over and over again in various bulletins and other works 

 on this subject, therefore are incorrect, at least in so far as South 

 Carolina is concerned. Specimens of the different stages were pre- 

 served at Columbia, and from these drawings have been made by 



70208—22 Bull. 1016 



