9 



knows at a glance exactly what particular species I am speaking of, 

 without the possibility of doubt, misconception, or confusion. An- 

 other instance : — I find that an insect, which will be fully treated of 

 hereafter as the "Apple-root Plant-louse" (Pemphigus pyri. Fitch), 

 and which, as I have ascertained, is doing an enormous amount of 

 damage throughout our State, destroying apple-trees by what is popu- 

 larly known as "rotten-roots," is commonly called almost everywhere 

 in Illinois "the Woolly Aphis." Now, if I speak of this insect solely 

 under this name, without adding its scientific name, every foreign 

 entomologist, and a good many American ones besides, will suppose 

 that I am referring to an entirely different kind of Plant-louse which 

 is properly called, both in America and Europe, "the Woolly Aphis" 

 (Eriosoma lanigera, Hausmann), and which is as different from the 

 species misnamed "Woolly Aphis" in Illinois, as a sheep is from a goat. 

 Whereas, if I give the scientific name, as well as the English name, 

 every entomologist from San Francisco, in California, to Vienna, in 

 Germany, will know exactly what insect I refer to. Moreover there 

 are already many purely scientific names, which pass current in the 

 mouths of every fruit-grower and even of every farmer. The verj^ 

 name "Aphis," which I have just been referring to as current every- 

 where in Illinois, is a purely scientific name, and for that reason I 

 have preferred to avoid it throughout in the body of my Report, and 

 to use instead the good old homely Anglo-Saxon word "plant-louse." 

 "Curculio" — which is upon everybody's tongue in Illinois, and alas ! 

 also upon everybody's plums and peaches and apples — is another - 

 purely scientific word, which has been popularized throughout the 

 length and breadth of the United States, though in scientific lan- 

 guage it has a much wider signification than in popular parlance and 

 is equivalent to the pure old English term "Snout-beetle." A third 

 scientific name which has been engrafted into our tongue is "Cantha- 

 rides," and it is always applied exclusively to a foreign species of the 

 same genus of Blister-beetles, to which belong the old-fashioned Po- 

 tato-bugs found for time immemorial in Illinois — not the new-fash- 

 ioned Colorado Potato-bug {Doryphora 10-lineata, Say), which only 

 invaded our State a few years ago, for that belongs to an entirely dif- 

 ferent group. Now, if the general reader can, without the least diffi- 

 culty, open his mouth wide enough almost every day of his life to say 

 "Aphis" and "Curculio" and "Cantharides," why should he be scan- 

 dalized, offended and annoyed by other scientific names ? always pro- 

 vided that they are printed in italics by way of a finger-post to warn 

 him off, as we stick up a board with "DANGEROUS" on it, where 

 the ice is likely to break through in a skating-park ; and provided fur- 



