352 ILLINOIS STATE HORTICULTURAL SOCIETY. 



ago. We can fully indorse what has already been the verdict of vegetable 

 physiologists on this subject, viz.: That "black heart" in trees does not 

 originate from cutting off the tap-root ; that when the tap-root is removed 

 from the young seedling, the growing tree provides itself with new roots, 

 both downward and in side directions, exactly as are needful for the good 

 of the future tree ; and that no facts have been adduced to show that 

 removing the tap-root has ever caused any discolored condition. 



We will further add, that it is a well-settled fact, where the wood 

 that has been discolored by the severity of winter is again covered over 

 by a good external growth, that the discoloration never extends into the 

 subsequent growth, the line of distinction between the new and discolored, 

 wood remaining permanent and distinct. 



Respectfully submitted, 



TYLER McWHORTER.) 



W. T. NELSON, }■ Committee. 



D. B. WIER, ) 



Prof. Cyrus Thomas, State Entomologist, presented the following 

 essay, which was illustrated with large colored drawings of many of the 



if 



insects described : 



THE BORERS. 



HY PROF. C. THOMAS, STATE ENTOMOLOGIST. 



Mr. President and Gentletnen of the Horticultural Society of Northern Ill- 

 inois : 



I am very glad to meet with you on this occasion, and trust that what 

 I may have to say on the subject selected — The Borers — may at least serve 

 to entertain you for a few moments, instead of proving a bore to you. 



As most of you are aware, from my address to the State Horticultural 

 Society, my present efforts, as State Entomologist, are directed chiefly to 

 the arrangement of some plan by which there may be co-operation among 

 the horticulturists of our State in their battle with insects. In order to 

 do this effectually, it is necessary, first, to study somewhat the methods of 

 generalizing remedies and preventives, as no consistent and practical plan 

 of co-operation can be formed until this has, to a certain extent, at least, 

 been determined upon. What I shall say to-day, in regard to the borers, 

 will have reference chiefly to the methods of determining, by the general 

 characters of the larvae or grubs, to what order they belong ; and also, 

 how they may be grouped, according to their operations. 



First, we may lay it down as a rule, which has but few exceptions, so 

 far as applied to our State, that this work, so far as done in the orchard, 

 nursery, and cultivated trees, is done by insects while they are in their 

 worm or larval state ; hence it follows, as a matter of course, that the per- 

 fect insects into which they are transformed must be sought in other 

 situations, because possessing very different habits. On this account, these 



