Remedy fob, the Plum Curculio. 



In the bulletin of the Ohio Agricultural Experiment Station for September, 1889* 

 Mr. Clarence M. Weed gives the following results of his experiments carried on through 

 two seasons, upon two varieties of cherry trees and four of plum trees, and during which 

 the large number of 65,500 cherries were individually examined, and any insect injuries 

 carefully recorded. He finds that " About three-fourths of the cherries liable to injury 

 by the Plum Curculio, can be saved by two or three applications of London purple in a 

 water spray, in the proportion of one ounce to ten gallons of water ; (2) That a sufficiently 

 large proportion of the plum crop can be saved by the same treatment, to insure a good 

 yield when a fair amount of fruit is set ; (3) That if an interval of a month or more 

 occurs between the last application and the ripening of the fruit, no danger to health 

 need be apprehended from its use ; (4) That spraying with the arsenites is cheaper and 

 more practical than any other known method of preventing the injuries of this insect." 



Remedies for the Striped Cucumber Beetle. 



The same careful observer, Mr. 0. M. Weed, gives an account of his experiments 

 with remedies for the Striped Cucumber-bettle (Diabrotica vittata) — the very common- 

 yellow beetle with black stripes along its wing cases (Fig. 48), which attacks, 

 cucumbers, melons, squashes, and other plants of the same family. A great 

 many remedies and preventives have been recommended for this insect. In 

 order to test the efficacy of these, Mr. Weed has carried out a series of experi- 

 *Fig. 48^ ments, and furnishes the following summary of results : 



The methods recommended were divided into four classes, viz : 1. The use of often" 

 sive odours in order to keep away the beetles. 2. Coating the plants with substances that 

 would produce a mechanical barrier to their feeding. 3. Poisonous coatings of the leaves 

 in order to kill the insects. 4. Preventing their attacks by enclosing the plants under 

 some form of tent or gauze-covered frame. 



The experiments were made on a large scale under ordinary field conditions during 

 the summer of 1889, when the striped beetles were exceedingly abundant. 



Five substances of the first class were tested, viz.: hen manure, cow manure, kero- 

 sine, carbolic acid and bi-sulphide of carbon. None of them proved practically successful. 



Three substances of the second class were tested, viz.: Coal-soot, gypsum and salt- 

 petre. Of these the soot and saltpetre proved worthless, while gypsum showed some 

 beneficial effect, but not enough wholly to save the plants. 



Three substances of the third class were applied, viz : — pyrethrum, " slug-shot," and 

 " peroxide of silicates." Pyrethrnm (Persian insect powder) killed those beetles with 

 which it came in contact when first applied, but soon lost its efficacy. " Slug-shot " in- 

 jured the plants to which it was applied. "Peroxide of silicates " 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 when the beetles were so numer- 

 ous that they burrowed down to meet the sprouting plants before they were out of the 

 ground. 



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 far the most 

 satisfactory. The cheapest and most successful method employed is 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 the edges down by small stones 

 or loose earth. It is better, however, to hold it up by means of a half barrel hoop or a 

 wire bent in the form of a croquet arch. 



Mr. C. P. Gillette, in the bulletin of the Iowa Agricultural Experiment Station for 

 May 1889, gives an account of his experiments on this insect, with much the same results 



