THE STATE ENTOMOLOGIST. V 



der to definitely decide this matter I took particular pains, while at 

 Hannibal during the summer, to inquire of the old fruit men there on 

 this point, and even John Fry, one of the oldest settlers, has never 

 heard of its appearance in that vicinity. The responses from numer- 

 ous letters that were sent, with the same query, to men living in other 

 northern parts of the State, are to the same effect. Believing there- 

 fore, that this insect can flourish in our extreme northern counties if 

 once introduced there, and that at present the fruit-growers of that 

 region are exempt from it, I cannot too strongly urge them to hold 

 the vantage ground they now have. Let every man therefore icho 

 reads this report, and who contemplates planting an apple orchard in 

 North Missouri, in duty to himself and to his neighbors, subject every 

 young tree which he receives from northern or eastern nurseries, to 

 a rigorous inspection; and if any be found infested, let them be 

 thoroughly cleansed before planting. By this means alone, can we 

 hope to retain that immunity, which we have so far enjoyed ! 



It should indeed be a maxim with fruit growers to inspect all 

 young trees received from a distance; for many of our very worst 

 insect foes, such as the Canker-worm, Hoot-louse, etc., are undoubtedly 

 transported from one place to another, principally on nursery stock. 

 In order that the Oyster-shell Bark-louse may be at once recognized 

 and thoroughly understood, I will proceed with its history : 



During the summer of 1867, three independent observers were 

 closely studying the habits of this insect in Northern Illinois, unbe- 

 known to each other, namely: Dr.H. Shimer, at Mount Carroll; Benj^ 

 D. Walsh, at Eock Island, and myself, at Chicago. Up to this time, 

 though it had frequently been treated of, yet much that was recorded 

 of its history was mere conjecture. For instance, Harris states that 

 there are two broods each year, while Fitch assures us that the scales 

 are the bodies of the gravid females, covering and protecting their 

 eggs ; neither of which is the case. 



The gist of Dr. Shimer's observations which were recorded in a 

 paper published in the Transactions of the American Entomological 

 Society, (Vol. 1, No. 4) are, 1st — that he discovered that the tarsal 

 joint of the newly hatched larva, which is very small, possesses no 

 claw, but is furnished at the extremity with four fleshy hair-like pro- 

 cesses upon which the young louse walks, and which he calls digituli; 

 2d — that the scale is constructed by the insect, and consists of the 

 moulted skins of the louse, soldered together by some secretion which 

 he believes to be the excrement. In these characteristics, he finds 

 sufficient grounds for separating this insect from the Bark-louse fam- 

 ily (Coccid^e) to which it has been referred by Linnaeus, Goeffroy, Fab- 

 ricius, Burmeister, Eeaumur, Curtis, Westwood, and many other au- 

 thors, and erects a new family (Lepidosaphitle), and a new genus 

 (Zepidosap7ies), to contain it. He furthermore takes it upon himself 

 to deny what all these authors have insisted upon, viz: — that the loss 

 of members, or the change from the perfect and active larval form 



