290 TRANSACTIONS OF THE HORTICULTURAL 



" The poison should be kept in a safe place and labeled '' Poison." 

 Do not distribute the powder with the hand, as is sometimes done. 

 An abrasion of the skin might result in serious harm. Apply the 

 powder with the wind, if any, so as not to breathe it. Do not use 

 it upon leaves or fruit which are soon to be eaten, or where it will 

 not l)e washed away by repeated rains (as on cabbage, cauliflower, 

 etc). Prevent animals feeding on poisoned vegetation, and poultry 

 from eating the poisoned insects. Test the strength of the poison 

 upon a few plants first, lest it may be too strong for the leaves. Use 

 it of no greater strength than is necessary to kill the insects." 



Pyrethram, or insect powder, is an insecticide of recent intro- 

 duction, which, though it may not have proved as efficient as was 

 hoped for by some, nevertheless serves a very useful purpose, and 

 will doubtless continue to increase in popularity as years go by. 

 When fresh and pure, this substance kills by contact many soft 

 bodied larvae, and certain other insects. It may be applied either 

 dry or in solution: a tablespoonful to a gallon of water. Pyrethram 

 consists of the dry powdered flowers of Pyrethram (P. roseum, P. 

 carneuni and P. cmerarwfolmm)^ and loses its insecticidal properties 

 after prolonged exposure to air. Hence the necessity of obtaining 

 the fresh article, often a difficult thing to do, because dealers palm 

 off their last year's supply as fresh, rather than throw it away. 

 Pyrethram is excellent for killing cabbage worms, cherry and rose 

 slugs, currant and other pests. 



Hellebore, a substance composed of the powdered roots of white 

 hellebore (Veratrum album), kills, both by contact with the skin of 

 insects, and also by being eaten. It is especially valuable for de- 

 stroying currant worms and similar insects. It may be applied as a 

 simple powder, or mixed with water, one ounce to two gallons, and 

 sprayed on. 



Kerosene. The last insecticide which I desire to mention, has, 

 like pyrethram, only recently been successfully used for this purpose, 

 but prouiises to occupy an important place in the future of economic 

 entomology. I refer to the kerosene emulsion, the introduction of 

 which is largely due to the efforts of the Bureau of Entomology of 

 the United States Department of Agriculture. Probably the soap 

 emulsion prepared according to the following directions, will prove 

 the simplest and most practical method of using, that has as yet been 

 recommended. The formula is: 



Kerosene 2 gallons— 67 per cent. 



Soap, common or whale oil i ft {33 ercent. 



Water i gal. ) ' 



Heat the solution of soap and add it, boiling hot, to the kero- 

 sene. Churn the mixture by means of force pump and spray nozzle 

 for five or ten minutes. The emulsion, if perfect, forms a cream, which 

 thickens on cooling, and should adhere without oiliness to the sur- 

 face of glass. Dilute before using, one part of emulsion with nine 

 of cold water. 



