— 203~ 



Jind stated that a monographic revision of the species was completed in 

 ]\ISS. and about ready for the printer. 

 Mr. Weed then read the following : 



EXPERIMENTS WITH REMEDIES FOR THE STRIPED CUCUM- 

 BER BEETLE. 



By Clarence M. Weed. 



[summary. ] 



(i). The ariicle read by the author embodies the results of the first 

 season's work on a series of experiments undertaken to determine the 

 preventive or remedial value of various methods recommended to pre- 

 vent the injuries of the Striped Cucumber Beetle, {Diabrotica viUafa.) 



(2). These methods are, for sake of convenience, divided into four 

 classes, viz: (i), The use of offensive odors ; (2), Mechanical coatings 

 of the leaves ; (3), Poisonous coatings of the leaves ; (4), Enclosing 

 plants under tents or gauze covered frames. 



(3). The experiments were made on a large scale under ordinary 

 field conditions, during the summer of 1889, when the Striped Beetles 

 were exceedingly abundant. 



(4), Five substances of the first class were tested, viz : hen man- 

 ure, cow manure, kerosene, carbolic acid and bi-sulphide of carbon. 

 None of these proved practically successful. 



(5). Three substances of the second class were tested, viz : coal- 

 soot, gypsum, und saltpeter. Of these coal-soot and saltpeter proved 

 worthless, while gypsum showed some beneficial effect, not sufficient 

 however wholly to save the plants. 



(6). Three substances of the third class were applied, viz : py- 

 rethrum, slug shot, and peroxide of silicates. Pyrethrum killed those 

 beetles with which it came in contact at first, but soon lost its efficacy. 

 Slug shot injured the plants to which it was applied. Peroxide of sili- 

 cates had a decided effect in preventing injury, and where the plants had 

 been well started before being attacked saved them from destruction. 

 But it did not save them where the beetles were so numerous that they 

 burrowed down to meet the sprouting plants. 



(7). The results obtained from the fourth method — that of fencing 

 out the insects by covering the plants with some form of tent or gauze 

 covered frame, were by flir the most satisfactory. The cheapest and 

 most successful method employed was that of protecting each hill by a 

 piece of plant cloth or cheese cloth about two feet square. This may be 

 done simply by placing it over the plants and fastening tlie edges down 

 by small stones or loose earth. It is better however to hold it up by 



