THE AMERICAN ENTOMOLOGIST. 



47 



of this insect the past year (187 1), both in 

 this and the northwestern States, I have 

 made the following calculations based upon 

 the statistics of the Department of Agri- 

 culture, with a reasonable estimate of the 

 proportional damage caused by this insect 

 to those crops upon which they depredate. 

 All such calculations must necessarily be 

 only approximately correct, and very 

 loose and extravagant conjectures have 

 sometimes been indulged in upon the loss 

 caused by Chinch-bugs in former seasons 

 of their prevalence. It has been my in- 

 tention to keep within reasonable bounds 

 and by giving the figures in the case, I 

 give others the opportunity to review 

 my estimates. 



" Taking the returns of the Department 

 of Agriculture, for the years 1869 and 1870, 

 for our guide, we may assume the present 

 annual yield of wheat in the State of 

 Illinois to be 30,000,000 of bushels, of 

 oats 40,000,000, and of barley 3,000,000. 



" The area seriously ravaged by these 

 insects, comprised, as we have above stated, 

 about the middle third of the State. This 

 section would bear its full proportional 

 third of the wheat and oats, and at least 

 one-half of the barley raised in the whole 

 State. This would give as the product 

 of that part of the State ravaged by Chinch- 

 bugs 10,000,000 bushels of wheat, upwards 

 of 3,300,000 bushels of oats, and 1,000,000 

 bushels of barley. The proportion of 

 these crops destroyed by Chinch-bugs we 

 have put at three-quarters of the wheat, 

 one-half of the barley, and one-quarter of 

 the oats. This will give as the amounts 

 actually destroyed by these insects, 

 7,500,000 bushels of wheat, 500,000 bushels 

 of barley, and in round numbers, 3,300,000 

 bushels of oats. 



" If we make a cash estimate of this loss, 

 by putting the price of wheat at one dollar 

 a bushel, barley at fifty cents, and oats at 

 twenty-five cents, we shall have an aggre- 

 gate loss of upwards of eight and a half 

 millions of dollars in the central third of 

 the State of Illinois. 



" In this estimate we have made no ac- 

 count of the injury done to corn through- 

 out the State, nor of the damage to small 

 grains north of the central belt. Here the 

 calculation becomes more indefinite, but I 

 believe it will be generally admitted to be 

 a low estimate if we add, for this purpose, 

 one-quarter part to the above aggregate of 

 loss. This will make the total loss caused 

 by Chinch-bugs, in the State of Illinois, in 

 the year 1871, upwards of ten and a half 

 millions of dollars. If we assume an equal 

 amount of loss for the two States of Iowa 



and Missouri combined, and another equal 

 amount for the four States of Indiana, 

 Kansas, Nebraska, and Wisconsin, we shall 

 have a total loss in one year, in the north- 

 western States, of upwards of 30,000,000 of 

 dollars, from this one species of insect." 



The loss in 1874 was probably equal to 

 that in 1864. 



Prof. Riley made a careful estimate by 

 counties of the loss in Missouri which he 

 found to aggregate the large sum of 

 19,000,000. I made careful estimates of the 

 loss on corn alone in Illinois by this insect 

 in 1874. These estimates were based on 

 different data so as to form checks the one 

 upon the other, and the loss by drouth 

 was eliminated. The result showed a loss 

 of about 20,000,000 of dollars on this 

 single cereal. The entire loss to the State 

 that year by the operations of this perni- 

 cious insect were not less than 30,000,000 

 dollars, I11.50 to each inhabitant. 



If the loss in the two States, Missouri 

 and Illinois, amounted to nearly 50,000,000, 

 it is not probable that the entire loss to the 

 nation by this diminutive insect in 1874 

 fell any short of 100,000,000 dollars. 



As the species appears to have a maxi- 

 mum of development about every five 

 years, the foregoing estimates render it 

 probable that the annual loss to the nation 

 by its operations averages ^20,000,000. 



The phylloxera has, up to the close of 

 last year, extended over more than 1,600,- 

 000 acres in France, and utterly ruined the 

 vines in 700,000 of them. The appearance 

 of the insect is even reported in the Medoc, 

 the most famous vine-growing section of 

 France, and Chateau Lafitte for which Baron 

 Charles Rothschild paid $830,000 two years 

 ago, is nearly ruined. At this rate, it is 

 expected that the whole district will be in- 

 fected before the end of next year. Sul- 

 phuret of carbon Is the most favored 

 remedy, though deep trenching and ma- 

 nuring, with an application of turpentine 

 and powdered rosin to the roots, is said to 

 be a cheaper and equally effective remedy. 

 Some vine-growers are planting American 

 stocks, thinking them less liable to attack. 

 — Land and Home. 



