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Mites infesting an old Grain Elevator. 



* * * I send you some verraia that I have been watching with interest for some 

 time, but which I know nothing of in a scientific way. If you can tell me anything 

 of them you will greatly oblige myself and a friend who is the unfortunate owner of 

 the souls and bodies of millions of them. They appeared about six weeks ago, 

 though they may have been there for some time without having been discovered, in 

 a grain elevator (a very ohl building which had stood vacant for years up to last 

 May) in a bin containing about 5,000 bushels of best lake shore wheat. They then 

 were like fine dust, almost microscopic, white and soft. There were none of the hard, 

 brown kind among them nor any of the long, dark headed ones. They have appeared 

 since. 



These insects are found only in this one elevator and in the one bin. They are 

 very numerous, sifting through the wheat and the spout so that one can sweep up a 

 quart ever}^ morning from the floor below. The wheat is freed from them by being 

 passed through a fan before shipping. * " *. — [Rowland Russel, 420 Milwaukee 

 street, Milwaukee, Wis., September 1, 1885. 



Reply. — * * * The " vermin '' which infest the grain elevator are mites (Acarina). 

 There were four species sent. The one which was tbe original infestor and which oc- 

 curs in the greatest number is Tyroghjpluis longior. The other species all prey on this 

 one. One of them, a siiecies of Ganiasiis, is very abundant, while the other two spe- 

 cies (Cheyletus eruditua and EupaJus sp) seem to be rare. The Gamasus will prob- 

 ably in a short time destroy a great majority of the TyroglypM, and thus the pest of 

 Vermin will correct itself. It will be very difficult to cleanse the elevator without 

 emptying it pretty well. I would advise the burning of sulphur all through the 

 building, especially where mites abound, and, where they are particularly thick, it 

 might be well to let a little bi-sulphide of carbon evaporate, remembering that this 

 vapor is heavier than air and that it is exceedingly inflammable. * * *. — [Sep- 

 tember 4, 1885.] 



Second LETTER. — * » # As yon say, the parasitic mites have largely destroyed 

 the smaller ones, and I suppose when their food is all gone they will die of starvation. 

 I do not want to trouble you further, but if yon know, will you tell me whether the 

 Tyroglyphus is a mite that affects the wheat alone and lives upon it exclusively, or 

 whether it is due to the aged condition of the wood-work of the elevator, and is likely 

 to infest anything stored there ? — [Sept. 9, 1885.] 



Second reply. — * * * I am glad that the predaceous mites seem to be suc- 

 cessful in their war of extermination, but it is not at all likelj'^ that they will per- 

 manently rid the elevator of the Tyroglyplii. If the wood-work of the elevator is old 

 and there is much moisture about it, only the most radical measures will rid it of mites, 

 now that they have established such a foot-hold. The contents should be removed 

 as far as possible and the building thoroughly dried, and it should also be fumigated, 

 as I suggested in my last. It should be repainted if possible, and all dirt and trash 

 cleaned up. This course will be expensive, and it is for the owner to decide whether 

 it will pay him to go to this trouble; but as I said before, it will be the only com- 

 plete and satisfactory way. T. longior feeds on flour, hams, cheese, and a variety of 

 other food products. — [Sept. 12, 1685.] 



The Streaked Cottonwood Leaf-beetle in the East. 



I send to you by mail to-day a box containing a beetle and larvai which, we find, 

 as a nuisance, is a fair rival to the potato-bug. 



It gets on the young leaves and shoots of the Carolina Poplar, eating the leaves 

 entirely off, and oftentimes destroying the bud on the end of the branches. 



We first noticed it about three years ago, but as there were so few of them we did 

 not take pains to destroy them, but thoy have been getting worse every year, until 



