48 TEANSACTIONS OF THE ILLINOIS 



Mr. Earle — The Winesap with us is perfectl}^ free; and our whole 

 country is covered with lady -birds. 



Mr. Holcomb — I have the White Pearmain^ the Carolina Eed 

 June and the Winesap. The Winesap is perfectly free and the others 

 are scabby. I have seen Pearmains that were fair^ but not in my 

 orchard. That particular part of the orchard is rather low, and has 

 not been cultivated like the others. 



Mr. Eiley — I can only say what I have said before^ that I incline 

 to believe that Dr. Hull has given us the true theory of scab ; yet I 

 can give no corroborative testimony^ and prefer to withhold a definite 

 opinion till the proper experiments are instituted another year. I have 

 long since believed that the lice were instrumental in causing the 

 gnarled appearance often observable in apples ; because their punctures 

 have the direct effect of causing a depression or sinking of the fruit 

 surface, or a shrinkage of the leal or stem. The only \YSiy in which I 

 can conceive that the lice produce scab, is by their punctures furnish- 

 ing a nidus for some cryptogam. As another fact which might militate 

 against the Doctor's theorj^, I will mention that the scab has exten- 

 sively prevailed around St. Louis the past season, notwithstanding the 

 lady-birds were unusually numerous early in the spring, and, aided by 

 the feathered birds, effectuall}- cleared the trees of lice. 



I can hardly conceive how the Spined soldier-bug — the Potato-beetle 

 enemy which Dr. Hull alludes to — could be instrumental in annihilating 

 the lady-birds, which are so active and fly so readily. I only know of 

 one instance where the soldier-bug has been observed to attack a ladj'^- 

 bird, and this species was the Nine-marked lady-bird, and not the 

 spotted species which is most common on our apple trees. Another 

 objection to Dr. Hull's theory is, that the lice are mostlj?- killed off by 

 their natural enemies, before the fruit is formed. 



As to the deadening of the spurs which Mr. McWhorter refers to, I 

 can only say that there is a kind of spur blight very common, which 

 is not caused by insects, while twigs are often killed by insects, espe- 

 cially by small boring beetles, belonging to the genera Tomiciis and 

 Scolyhis. The former kind, or that not caused by insects, was very 



