l897-] ENTOMOLOGICAL NEWS. lOI 



DEPARTMENT OF EGONOMIG .ENTOMOLOGY. 



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



Papers for this department are solicited. They should be sent to the editor, Prof. John 

 B. Smith, Sc.D., New Brunswick, N.J. 



The Onion Maggot.— The question of dealing with root maggots has 

 always been a troublesome one for two reasons. In the first place the 

 creatures feed concealed, so that no sign of their presence is noticeable 

 until the plant is so injured that in many cases it is beyond redemption. 

 Secondly, applying insecticides which are sufficient to destroy the mag- 

 gots is extremely expensive, and at the same time a little risky to the 

 plants themselves. There has been a great deal of contradictory testimony 

 in the matter, and materials that have, according to reports, proved per- 

 fectly satisfactory in the hands of some have been useless when applied 

 by others. Mr. Slingerland has obtained excellent results with bisulphide 

 of carbon against the cabbage maggot, and has also found a carbolic acid 

 emulsion to be useful when properly applied and used in time. My own 

 efforts have been directed as far as possible to the discoverj' of some 

 means of cultivating or applying specific fertilizers or both, for either the 

 prevention of injury or the destruction of the pest. 



In 1893 one of the leading onion growers in New Jersey with many acres 

 cultivated for the production of seed and sets in Cumberland County, 

 wrote me that the pest had appeared on his place for the first time. He 

 had grown onions on this farm for several years previously, and accord- 

 ing to his own story had never had the slightest trouble, had never seen 

 a maggot in his onions and had not lost a plant. I have every reason to 

 believe that this statement was correct, for the man is a close observer 

 and one of those who succeed in making farming pay, which, it will be 

 admitted, is a sign of more than average intelligence under present con- 

 ditions. At my suggestion fertilizers were employed, and the experience 

 since 1893 is here presented in the belief that sufficient time has elapsed 

 to make it possible to judge of its effectiveness. I will say that our cor- 

 respondent keeps books. It is his object to discover just exactly how 

 much each crop costs him and just how much profit he makes or what 

 losses are sustained from every piece of land under cultivation. He 

 therefore notes not only the cost of the materials that go into the land 

 and the cost of cultivation, but also any circumstances that affect the 

 value of the crop or add to the expense of raising. The notes, therefore, 

 are reliable, as being made at the time and not being merely a recollec- 

 tion of what was done. 



1893. — The onion sets were put in the field March 30, 1893. Maggots 

 discovered at work on them May 2d. We at once commenced taking 

 <out with trowels all onions showing infestation by the withered appear- 

 ance of the iwo lower leaves on the stem being careful to remove most 



