1893-] ENTOMOLOGICAL NEWS. 297 



DEPARTMENT OF ECONOMIC ENTOMOLOGY, 



Edited by Prof. JOHN B. SMITH, Sc. D., New Brunswick, N. J, 



Greasy Lepidoptera. In the "Entomologist" for October, 1893, Mr. H. 

 G. Knaggs speaks of having been experimenting with ether for the ex- 

 traction of grease from insects, and particularly Lepidoptera, and begs 

 that greasy insects be sent him for purposes of experiment. While the 

 subject is perhaps not strictly economic, yet it has an interest for all col- 

 lectors, even on the smallest scale. It is surprising, however, that in 

 England the use of ether for such purposes should not be known, for it is 

 with us perhaps the most common of the materials used. I have not 

 made any attempt to look over the literature on this subject, but I have 

 found almost universally, that ether is the favorite liquid employed by 

 collectors great and small, and in my opinion it is not even the best. It 

 is certainly effective, but it is not nearly so useful in my experience as 

 chloroform. This latter acts quicker, just as thoroughly, and may be used 

 several times in succession, before it becomes saturated with grease. In- 

 deed, very frequently I do not even immerse the insect in the liquid, but 

 with a medicine dropper simply drip the chloroform on the insect in such 

 a way that it runs from end to end of the specimen, and with a very small 

 expenditure of liquid, nearly or quite all the grease is removed in a very 

 few minutes. For use on a larger scale I have found nothing that is better 

 than a high grade of gasoline. This in the first place is very cheap, cost- 

 ing not more than fifteen cents a gallon, so that it is possible to use it 

 liberally, without feeling that the specimens were costing more than they 

 were worth. Insects of all kinds can be safely immersed in this liquid 

 and left there for an indefinite time without staining or losing color, and 

 when removed the specimen requires but a few moments to become dry 

 and regain its bright appearance. 



Experiments on the Pear Midge. I have in this department several times 

 called attention to this insect, and to the fact that it is gradually spreading 

 through New Jersey. During the past season it has invaded a new 

 county, and I have made a Series of experiments as to the effect of cer- 

 tain fertilizing materials upon the insect after it had gone under ground. 

 I reported, some time during the Summer, that in an orchard in which 

 the midge made its appearance last year, the. ground was at my sugges- 

 tion given a heavy dressing of kainit, the land under the infested trees 

 being treated at the rate of nearly a ton to the acre, while the remainder 

 received about half that amount. This Spring that orchard was almost 

 entirely free from the midge, only a very few infested pears being found 

 at the edge of the orchard, where the midges could easily have come on 

 from a neighboring plantation. Immediately adjoining this orchard is 

 another, which was also infested last year, and which was not treated in 

 any way. This Spring there was not a single Lawrence pear in it that 



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