16 



THE PRACTICAL ENTOMOLOGIST. 



not be imaj^ined that the loss of the consumer is 

 here the gain of the producer. For althoujih the 

 farmers in the infested district get an enhanced 

 price for their potatoes, yet their crop is so much 

 lessened in quantity, that on the average they gain 

 nothing at all, many of them actually losing their 

 entire crop, although individual farmers, whose 

 crop happens to have escaped the scourge, do, of 

 course, gain by the enhanced price. 



The whole potato-crop of the United States, if it 

 continues to increase at the same rate as it has hith- 

 _erto dune, will be in the year 1880 about 186 mil- 

 lions of bushels. Suppose it is only 100 millions 

 of bushels in 1880. By the year 1880, at the la- 

 test, I have calculated that the new Potato Bug 

 will have reached the Atlantic Ocean and occupied 

 the whole country. Whence it follows that an en- 

 hanced price of 25 cents a bushel on the greatly re- 

 duced crop of 1880 would foot up txoenty-five mil- 

 lions of dollars ; and that, judging of the future 

 from the past and the present, we may anticipate 

 some such enhanced price, in consequence of the 

 continued migrations of this insect. And yet we 

 are often told by men, who never look two inches 

 beyond the tips of their own noses, that insects are 

 little contemptible vermin, unworthy the notice of 

 any grown man ! B. D. w. 



The Canker Worm. 



I have already in sundry " answers " to Corres- 

 pondents expressed my belief, that the reason why 

 tarred bandages were found an insufficient protec- 

 tion against this insect was, that they were not ap- 

 plied early enough in the season. All the best au- 

 thors say, that many of the wingless female moths 

 come out late in the autumn, and even on fine 

 warm days through the winter; and consequently 

 that the tarred bandages, or the leaden troughs 

 full of oil, or the Patent Protectors, or whatever 

 else you use to prevent the female moths from 

 climbing the trees to lay their eggs thereon, must 

 be applied as soon as these female moths begin to 

 come out. The following extract from an Article 

 on the Canker-worm by Col. D. S. Dewey, of Con- 

 necticut, shows that he, at all events, made the mis- 

 take above referred to. Like some unreasonable 

 patients, he does not take the medicine at the time 

 that the Doctor orders it to be taken, and then 

 blames the poor physician because he is not cured. 

 Failing as above stated, in my review of the volumes 

 of the Horticulturist, to find printed testimony, recourse 

 was next had to parole evidence. The only knowledge 

 thus attainable was that tar was the remedy. So, tar it 

 was; and, for si.xteen successive evenings, (commk^^cing 

 M.VRCH 17, 1865,) the application was f:iithfully made, up- 

 on some sixty choice apple trees. Many neighbors fol- 

 lowed suit; "any quantity" of grubs were caught: but 

 the result uniformly showed a perfect waste of time and 

 money. — The Horticulturist, July, 1866. 



Col. Dewey will probably say, that it is alto- 

 gether too much trouble to tar his trees both spring 

 and fall and on warm d lys through the winter. 

 Perhaps it may be so. Very well. Then let the 

 Canker-worm take his natural course, and see if he 

 does not ruin all your trees in three years. Perhaps 

 the medicine is too nau.seous to swallow. Very well. 



Then throw it out of the window and see if you 

 will get cured without it. But do not be unfair 

 enough to halve the dose, and then blame the phy- 

 sician because he does not cure you. 



But IS it too much trouble to tar all the trees in 

 an orchard according to the most approved direc- 

 tions ? or, to speak more rationally, will it pay, as 

 a question of dollars and cents? The Colonel can 

 calculate better than I can, what is the money value 

 in Connecticut of an average crop of apples from 

 sixty average trees, less the expense of harvesting 

 and marketing and the rent of the land they grow 

 on. He can also calculate what will be the money 

 cost of tarring sixty trees, say, to be on the safe 

 side, ninety different times. I take it the apples 

 will out-foot the tar at least ten-fold. And if he can 

 only persuade his immediate apple-growing neigh- 

 bors to follow the same plan, honestly and faith- 

 fully, for one or perhaps two seasons, he will — pro- 

 vided there are no forest-trees in his immediate 

 neighborhood afflicted by the Canker-worm — be rid 

 of this pest probably for half a lifetime. For the 

 Canker-worm Moth cannot fly in upon him from 

 the other end of the county, as the moth of the 

 common Caterpillar (^Clisiocampa americana') 

 would do, if he and his immediate neighbors were 

 honestly and faithfully to destroy every single 

 caterpillar-nest on their trees for one or two years. 

 •'Curst cows have short horns;" and the female 

 Canker-worm Moth cannot fly at all. 



Another thing. It is demonstrable that the Colo- 

 nel is in error when he asserts, that applying the 

 tar, even in the perfunctory manner he adopted, 

 was "a perfect waste of time and money." He ex- 

 pressly says that the tar stopped "any quantity of 

 grubs," (meaning, I suppose, the female Canker- 

 worm Moths,) from climbing the trees. Now if 

 there had been no tar on his trees, all these hateful 

 "grubs" would have mounted his trees and laid 

 their eggs there, and instead of measuring his Can- 

 kerworms by the bushel, he would have had to 

 measure them by the wagon-load. Even half a 

 dose of quinine will help the ague a little ; but that 

 is no reason why, when the physician orders a full 

 dose, the patient should, out of wilfulness, or con- 

 ceit, or sheer carelessness, take only half a dose, 

 and then grumble because he is not completely 

 cured. b. d. w. 



The Cankerworm Again. 



The Secretary of the Michigan State Agricultu- 

 ral Society, finding that "that pest of apple-or- 

 chards in Eastern Massachusetts, the Canker-worm, 

 has been colonized in Michigan," writes to the 

 New England Farmer for advice as to the best 

 mode of attacking it. In reply, the Editor of the 

 Farmer states that " tarring the trees is effective, 

 if it is effectually done," i. e., as is afterwards ex- 

 plained, if the process is continued " from Novem- 

 ber to April." He thinks, however, that oil and 

 rosin, boiled together in certain proportions which 

 have to be a.scertained by "the rule of thumb," an- 

 swers a better purpose than tar, because it does not 

 dry up so much on hot days, and therefore does not 



