6 CONTENTS. 
Remedial and preventive measures—Continued. 
The ridge and: coal=tar method---_+*-- Se eee 
Other barrier method s__ <2 =~. 2 2 a ee eee 
Necessity for preventing chinch bugs from becoming established in 
fields of wheat and ‘crass. 2 =) * eee 
Summary of remedial and preventive measures_______-_-__-_-___-__ 
Probable orizin and diffusion of therchincehy pis 
Indications of a probable distant origin and later diffusion__________ 
Unique appearancerandseresariois pivot ee eee 
Occurrence of the long and short winged forms and their distributicn_ 
Relation of the inland and seacoast short-winged forms _________-____ 
Probable courserorcdithw stoma see ae eee ee eee ee 
Habits of the European species, Blissus doriw Ferr__________________ 
Previous ideas on the diffusion of the chinech bug___________________ 
Reasonsitor the present theorysot dif usion= 9 
MV CY ie = Shee ce A pe I ges a Or ee a 
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ri) 
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$3 
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