198 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



and that it was extremely doubtful if anj' of them had ever 

 been tested over as large an area as a single acre, even. In several 

 cases it seemed probable that the person concerned had really experi- 

 mented with the cabbage maggot and had merely inferred that a 

 treatment successful there would also prove efficient in onion fields, 

 not realizing that the different method of growing onions might affect 

 the results. 



After a prolonged study of the treatments advised, eight of the 

 most promising were selected for trial, the others being prohibitive 

 on their face, either because of the difficulty of obtaining the material 

 in sufficient cjuantities for extensive experiment, its cost, or an evident 

 great expense in its application. These eight were: carbon disulfid; 

 nicine; powdered hellebore; hellebore decoction; soap wash; carbolic 

 acid and lime; kerosene emulsion; and carbolic acid emulsion. 



Time does not permit the presentation here of the details of the tests, 

 which are given in the 25th Annual Report of the Massachusetts 

 Agricultural Experiment Station. The results, however, are briefly as 

 follows : 



The carbon disulfid when placed near enough to the plants to pro- 

 tect them from the maggots, killed most of the plants. It is possible 

 that a long series of tests would show that a certain amount placed 

 at some certain distance from the plant would give protection with- 

 out injury, but the application of any treatment, with the accuracy 

 this would require, to a ten-acre field would be impossible except at 

 a prohibitive cost. If a second treatment were necessary as would 

 probably be the case, it would become still more impracticable, while 

 the cost for a single application w^ould be from $12 to S14. For 

 these reasons, therefore, the carbon disulfid method may be dismissed 

 as not feasible. 



Nicine was tested mainly from curiosity to learn if it was an insect 

 repellent as it was claimed to be. It was found to have no protective 

 value, and at the prices quoted its cost would be prohibitive in any case. 



Powdered hellebore dusted along the rows cost over fifty dollars 

 for each apphcation, including the labor. The treatment would 

 need to be repeated at least once, and probably twice, bringing the 

 expense too high. The results also, were far from satisfactory. 



Hellebore decoction prepared according to Smith's directions (N. J. 

 Bull. 200) seemed to give no protection whatever to the onions and 

 the cost of material and its application three times would ])e greater 

 than the average loss without treatment, even if good results had been 

 obtained. 



Soap wash using one pound of soap in ten gallons of water, poured 

 along the rows, three times at intervals of ten days, gave only moder- 



