66 



having the first leisure moment that I have had, I visited the 

 infested fields. The field examined was a fine, rich, level prairie, 

 thoroughly underdrained with tile, and has been cultivated in corn 

 for a number of years. The ground was clean, and the crop had 

 been well attended. The corn was a fair growth, and had just 

 begun to ear. At first one would not think there was anything^ 

 amiss with it, but on close inspection I could see that many hills 

 were withering, and on taking hold of them, they pulled up very 

 easily, and the fibrous roots were found all eaten away. A closer 

 examination revealed hundreds of small white worms about half an 

 inch long, and the size of a No. 5 Klager pin. The corn had thrown 

 out its first row of brace roots, and in these I found numerous- 

 worms at work. Some hills that had been attacked earlier had not 

 developed brace roots, but had thrown out another set of fibrous 

 roots from the stalk, and these had been attacked by the worms. 

 I thought the worms were the larvge of some Bcarabaeidae, but could 

 not determine. The field examined contained eighty acres, and had 

 a large field adjoining it on the west. The damage in this field will, 

 I think, amount to at least one-third of the entire crop. I examined 

 several hills that appeared as yet unaffected, but found the worms 

 in the brace roots." 



The worms sent me proved to be, as Dr. Boardman had stated, 

 the larvae of some beetle, but 1 did not think they belonged to the 

 family given in l\is letter. Their size and shape more resembled 

 the larvae of Diabrotica Vittata, or the Striped Cucumber-beetle, than 

 anything else with which I was familiar ; and in my reply to his 

 letter I told the Doctor that I thought they must belong to the family 

 Chrysomelida3, and possibly to the genus Diabrotica, though at that 

 time I did not know that any of the species attacked the roots of 

 corn. 



After we were through with our investigations, we found that Dr. 

 C. V. Kiley had referred to its having been found working in the 

 roots of corn in Missouri, in the introduction to his report to the 

 Commissioner of Agriculture, March 1st, 1879. (See page 208, Agri- 

 cultural Report for 1879.) The worms were placed in a suitable 

 dish for rearing, as that alone would settle the question as to wha 

 they were. But before the perfect insects were developed. Dr. Board- 

 man wrote again, under date of August 5th, as follows : 



*'In regard to those worms infesting the roots of corn, I am 

 inclined to think your conjecture will prove correct. I have again 

 examined the ground, and find large numbers of Diabrotica Longi- 

 cornis on the stalks of the corn, and also a number of the pupae in 

 the ground under the corn. When I gathered the worms that I 

 sent you, I noticed a number of them in one or two hills where the 

 worms had disappeared, but did not mistrust that the worms could be 

 the larvae of a Diabrotica. I have examined your reference to Le- 

 Baron and Thomas, and it goes far toward confirming the opinion 

 that you are correct. D. Longicornis have been very bad on our 

 vines this year ; in fact, more troublesome than D. Vittata. I have 

 usually found them very plenty on thistles, but have not seen them 

 do much damage to vines until this season. This is another cir- 

 cumstance that leads me to think your conjecture correct. I have 

 never before found them in any numbers on the corn." 



