THE PRACTICAL ENTOMOLOGIST. 



rounds about as often as it is supposed a new set of 

 readers have grown up, who never heard of it. At 

 every period of its appearance it has been followed 

 by proof that it was good for nothing, but it will 

 come round again. It was last started by a corres- 

 pondent of the Prairie Farmer, and was extensive- 

 ly copied. 



To know that such things not only do no good, 

 but do positive harm, I would merely refer to the 

 issue of the paper above mentioned of the 9th inst., 

 in which a correspondent states, that when he saw 

 the story of destroying canker-worms with sulphur, 

 he thought it was so plausible that he determined 

 to try it, and accordingly " put twenty-seven pounds 

 of flowered sulphur in and on about one hundred 

 and twenty trees ; and the result is, that the foli- 

 age of the trees is nearly all eaten up and the fruit 

 nearly all destroyed." Just as might have been 

 expected. 



Permit me, in conclusion, to acknowledge the 

 obligations I am under to Allen T. Lacy, Esquire, 

 of JIarengo, and Hon. S. S. Lacy, of Marshall, for 

 valuable information and assistancer endered me, in 

 the prosecution of my inquiries respecting the ap- 

 pearance of the canker-worm in the locality above 

 mentioned. Sanpord Howard. 



Fire-blight. 



Recently we have had accounts from Northern Ohio 

 and other sections, speaking of a hlight aflecting the 

 ends of all young twigs in pear, apple and quince trees. 

 In some cases not only is this year's growth aiiected, 

 but more or less of the last year's growth, until the trees 

 loolc as if a big fire had been made near and scorched them. 

 Can our entomologists tell us if this be not (as we suspect) 

 the attacli of the kcolytus pyri, and is it not because of the 

 crude sappy condition of the tree ? — KorticvXturistj Au- 

 gust, 1S66. 



Remarks by B. D. W. — Unless the writer re- 

 fers to the curling up of the leaves by the common 

 Aphis or Plant-louse, this must be the notorious 

 Fire-blight, which has for years been the scourge 

 of Pear-growers, and in a far less degree of Apple- 

 growers. Whatever be the cause of this Blight, it is 

 most certainly not produced, as Harris and Fitch sup- 

 posed, by the minute Boring-beetle known as Sco- 

 li/tus 2)yri. For I have searched whole orchards 

 perishing by the Blight in Illinois, and failed to 

 find this insect or the slightest indications of its 

 work. As to Mr. Dowuing's theory that it is some- 

 times caused by "Frozen sap," it is pure unmixed 

 hypothesis unsupported by a single fact. Indeed 

 both facts and common sense are opposed to it. In 

 a pear-orchard of fifty trees, five or six trees perhaps 

 are blighted every year, not in any particular corner, 

 but promiscuously. Why should Jack Frost select 

 these particular trees to freeze their sap and let the 

 others alone ? Besides, if frost caused Blight, we 

 should have Blight most prevalent in the summer 

 following a severe winter ; which is not found to be 

 the case. " What then," it will be asked, " is the 

 cause of Fire-blight 1" I can only answer that I 

 do not know. I have, indeed, an opinion on the 

 subject; but believing is not knowing, and faith is 

 not fieience. 



The Hessian Fly. 



■Wheat growers suffer greatly by the ravages of this in- 

 sect. It can be easily destroyed in the following man- 

 ner: — About the middle of August sow a strip of wheat 

 adjoining where you intend to put your crop — say one or 

 two acres. About the middle of September sow your field. 

 "When that has come up and shows cleverly, plow under 

 deeply the first sown. The fly is headed, and your crop 

 is safe. — Caiman's Mural World. 



Remarks by B. D. W. — I suspect that the 

 whole virtue of the above prescription lies in sow- 

 ing the crop in the middle of September, and that 

 the strip sown in the middle of August does little 

 or no good, except by preventing a man's home- 

 grown Hessian Flies from straying away to trouble 

 his neighbors. It has long been known that wheat, 

 that does not appear above ground till after the 

 Hessian Fly has disappeared, escapes the ravages 

 of that insect. Five years ago I found that the 

 farmers in Southern Illinois were fully aware of 

 this fact, and governed their time for sowing ac- 

 cordingly. Usually the Fly comes out about the 

 first few weeks in September and disappears in a week 

 or so, the time varying a little according to the la- 

 titude. But the safest rule is to notice in each 

 neighborhood, at what date the latest sown wheat 

 that is taken by the Fly was sown, and to sow for 

 the future a little later than that particular date. 



ANSWEKS TO CORRESPONDENTS. 



jS9"To Michigan Corkespondents. — A Michigan firm, 

 doing business in the nursery line, sent me their sub- 

 scription for six copies of Vol. 11, of the Practical Ento* 

 MOLOGiST. This I duly forwarded to Philadelphia, along 

 with other matter, but it failed to reach head-quarters, 

 through the fault of the Post-office. Will the firm please 

 repeat their subscription, as I carelessly omitted to take 

 a note of their names ? b. d. w. 



T. U'Graw, Wise. — The black worms, striped length- 

 ways with many narrow yellowish lines, witli two long 

 black horns on their necks, and about an inch long, are the 

 larvae of a large reddish-brown Moth, Dryocampa senato- 

 ria, and they feed exclusively on the Oak. You say your- 

 self that you took the specimens sent, off an Oak. There 

 is a very similar worm, as to its black color and yellow- 

 ish lines, but differing in having no black horns on itsneck 

 and in the neck itself being usually bright yellow, whence 

 it has been called in English "the yellow-necked worm" 

 by Dr. Fitch. It has the singular habit of generally sit- 

 ting when at rest with its head and tail each cocked up 

 in the ^ir, which the other one never does. This "yellow- 

 necked worm" feeds indiscriminately either on the Ap- 

 ple-tree or on the Oak, as I have recently proved by shift- 

 ing a large brood of them, taken off the Oak, on to a diet 

 of apple-leaves, upon which they thrive most admirably. 

 It is also found on several other trees, Thorn, Ac, and 

 Dr. Warder says that he found it to infest the Peach. It 

 produces an entirely different moth from that produced 

 by the first worm, and its scientific name is Dalaiia min- 

 istra. As you may see from the back numbers of the 

 Practical Entomologist, Dr. Warder of Ohio finds this 

 insect a terrible pest in his orchards ; and no doubt it was 

 this species, and not the one which you sent me, which, 

 as you say, "stripped all the leaves off your apple-trees 

 and is now feeding on Burr Oak." Mind now, I do not 

 at all dispute the fact, that "yellow-necked worms " mi- 

 grated from your Apple-trees on to your Oaks — for I know 

 they can do this by actual exjieriment. All I say is, that 

 you sent me by mistake specimens which are entirely 

 difl'erent from those that really stripped your apple-trees, 

 aud which never will and never can feed upon apple- 

 tree leaves. If you doubt this, try the experiment j'our- 

 self, and you will soon see that the worms with two long 

 black horns on their necks will die before they will eat ap- 

 ple-leaves. 



