CHAPTER VIL 



INSECTS IXJURIOUS TO CORN 



IN^JUKIKG THE ROOTS. 



Corn Root-worms. 



The Western Corn Root-worm {Diahrotica longicornis Say). 



The farmers and entomologists of the Central States 

 have long known this as one of the worst pests with which 

 they have to deal, and its progress eastAvard through Ohio 

 has been a matter of considerable interest. 



Hidorii. — Outside of entomological collections, the 

 beetle was hardly known until 1878, when it first appeared 

 in Illinois in such numbers as to cause any wide-spread 

 damage. First observed by Say in 1823, who gave its 

 habitat as Arkansas Territory, it was not again noticed 

 until found numerous upon sorghum by Prof. AV. S. 

 Robinson of Kansas in 1866, who gave a large thistle as 

 its native food-plant. In 1874 Prof. C. V. Riley received 

 a larva from Kirkland, Mo. , which had been found bur- 

 rowing into the roots of corn with considerable injury, 

 and again in 1878 from Eureka, Mo. Prof. Webster states 

 that in Illinois from the spring of 1874 he collected only 

 two specimens until the fall of 1877, when quite a number 

 were taken in corn-fields. A rapid increase in numbers 

 occurred during the next three years, and by 1880 its 



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