108 TE AN S ACTIONS OF THE ILLINOIS 



example of this , I may state that the leaves and shoots of all russet varieties are 

 selected in preference to the fruit. Also, I could mention, as being mainly exempt 

 from their attacks, the fruit of Keswick Codlin, Duchess of Oldenburg, and other 

 sorts. On the other hand, the fruit of Early Harvest, Carohna, lied June, Nevrtown 

 Pippin, "Winesap, and many other fine sorts, in localities vphere the louse abounds, 

 were this year totally ruined. 



The injury done to our apples by this insignificant little louse, results from its punc- 

 turing and sucking the juices of the young fruit just before and after it is in bloom. 

 At these punctured points growth is arrested. After the louse has disappeared, 

 fungoid growths attach to the wounds and quickly spread from one wound to another, 

 and so far as they extend, arrest the external growth . If an examination is delayed 

 until after the disappearance of the louse^ or until these fungoid growths or their 

 effects are visible to the unaided eye, then the punctures made by the louse can not 

 well be detected, and the injury, \aewed at this time, would appear as of fungoid 

 origin. 



The injury done to the apple crop, by the apple tree louse, cannot well be esti- 

 mated. Its mischievous operations are not confined to certain orchards or States. All 

 parts of the West, and probably the East, also, sufler great loss annually, by reason 

 of its depredations. 



"What is remarkable of the past respecting our knowledge of this insect, is, that we 

 should not have found out that it was its normal habit to puncture the germs of fruit, 

 as well as the tender leaves and branches. But for the chance desire, on my part, to 

 study the structure, the habits, and the possible mischief done bj^ this louse, orchard- 

 ists might have gone on in blissful ignorance for j-ears to come, as in years past, 

 discarding one variety of apple after another, until our last variety subject to the 

 attacks of lice had been rejected. 



In the latter part of June, 1868, Mr. B. D. Walsh, State Entomologist, spent a 

 week in the Alton district, prospecting the bugs. While here, Mr. W. was greatly 

 pleased to find a cannibal beetle feeding on the Colorado potato bugs. So greedy and 

 energetic were these cannibal insects found to be, that only four to eight days were 

 required by them in which to destroj^ all the potato bugs in the worst infested fields. 

 Pursuing his investigations further, Mr. W. found the cannibal on the Colorado 

 bug also feeding on lady-birds. To these discoveries I will add, that at the end of the 

 summer, in the Alton region, so general had been the destruction of the lady-birds, 

 that not one could be found. All, or nearly all, had fallen a prey to the rapacity of the 

 same cannibal insect that destroyed the Colorado potato bug. This circumstance in 

 itself is insignificant enough, and perhaps the reader is ready to inqiiire what possible 

 connection there can be between the appearance of a cannibal on potato bugs and 

 lady-birds with that of the scab on apples. 



Perhaps this wiU better be understood when we explain: In the fall, after the 

 apple tree lice become winged, they lay clusters of eggs on the young shoots, as before 

 mentioned. These lice eggs are greedily sought after by the lady-birds. In the fall 

 and early spring, the lady-birds consume a vast number of these eggs. From the eggs 

 that are not eaten, little colonies of lice are hatched. In the midst of these young 

 lice, the lady-birds drop a few of their own eggs, which soon hatch, producing small 

 larvffi. These larvss of the lady-bird immediately commence preying upon the apple 

 tree lice, catching and devouring them with the greatest avidity, one after another, in 



