Plant Sanitation. 



318 



[October, 1911. 



PLANT SANITATION. 



BOOK-NOTICE. 



Insecticides. By H. Maxwell-Lefroy, 

 m.a,, p.l.s., P.Z.S., Imperial 

 Entomologist. 



Office of Government Printer, Calcutta. 

 Price 12 annas or Is. 2d. 



This useful circular is issued as 

 'Bulletin No. 23' of the Agricultural 

 Research Institute, Pusa. Its sub-title is 

 "Mixtures and Recipes for Use against 

 Insects in the Field, the Orchard, the 

 Garden and the House." The author 

 expressly excludes the discussion of in- 

 secticides and methods employed against 

 pests of plantation crops, as these have 

 been dealt with elsewhere, but he 

 describes succinctly the most approved 

 remedies for the common pests of every- 

 day life in the East. The bulletin is 

 brief, but to the point. It consists of 

 22 pages and half as many well executed 

 plates, the latter illustrating various 

 forms and parts of spraying machines. 

 The following selections from the 

 sectional headings will give an idea 

 of the comprehensiveness of the 

 work: — "Insecticides on Field Crops," 

 " Insecticides for Fruit Trees"; "In- 

 secticides in the Garden"; "Soil Insect- 

 icides" ; " Insecticides in the House" 

 (treating of Clothes, Moths, Cockroaches, 

 Fish-insects, Fleas and Mosquitoes), etc. 

 From this it may be judged that Mr. 

 Lefroy's little book should find a place 

 in every household, and be on hand for 

 ready reference. 



A commendable feature of the work is 

 that preference is given — in every case — 

 to the simplest and least expensive 

 remedies. Of the numerous proprietory 

 insecticides that are constantly being 

 launched upon the market, the author 

 remarks that "not one of them is equal 

 to the simple preparations here described, 

 and we have yet to find any reliable 

 ' patent ' insecticide whose price and 

 efficacy bring it within the range of the 

 ordinary ones we use and recommend." 

 The present writer can speak feelingly 

 of the time wasted upon the testing of 

 numerous samples (large and small), at 

 the urgent request of the inventors or 

 their agents, all of which owe their pro- 

 perties to some simple ingredient — 

 usually soap cr petroleum— which can 

 be obtained for a fraction of the cost of 

 the patent mixture. The author gives a 

 catalogue of articles, to be purchased 

 locally or made up from easily pro- 

 curable ingredients, which will meet 

 with nearly every requirement. The 

 list includes s— 



Lead Chromate, for biting insects on 

 field crops : 



Naphthalin Emulsion, for the veget- 

 able garden : 



Crude Oil Emulsion, for sucking 

 insects : 



Book Solution, for the preservation of 

 bindings : 



Pyrethrum Powder, for vermin : 

 and such simple ingredients as Rbsin, 

 Soda, Sanitary Fluid or Phenyl, Arsenic, 

 Citronella Oil, Copper Sulphate, Lime, 

 Borax, Naphthalin, and Soap. 



Lead Chromate is an insecticide in- 

 troduced by Mr. Let' roy to take the place 

 of the better known but more dangerous 

 arsenical compounds. After exhaustive 

 tests he pronounces it to be a perfect 

 substitute for arsenical poisons. Its 

 conspicuous yellow colour makes it 

 easily seen on the plants and is a safe- 

 guard against accident. 



Naphthalin emulsion is, I believe, a 

 novelty. It has been evolved to meet 

 the need for a rapid but evanescent in- 

 secticide, and is employed more especi- 

 ally for such vegetables as " well-formed 

 cabbages or lettuce which will soon be 

 cut." It is described as " an insecticide 

 that should be in every garden, as it is 

 extiemely effective for a short time and 

 leaves no trace on the plant by next 

 day." The formula for the preparation 

 of the emulsion is as follows ; — " Dissolve 

 6 oz. concentrated size in | gallon of hot 

 water, and add 1 lb. soft soap. Dissolve, 

 in two gallons of kerosene as much 

 naphthalin as it will absorb ; at ordinary 

 temperatures about 2 lbs. 12 oz. is 

 taken up ; by warming carefully in the 

 open over a small fire, 8 lbs. of napthalin 

 will dissolve. Add the napthalin solu- 

 tion to the hot size-soap solution, add 

 I gallon of water and churn or agitate 

 with a syringe or sprayer." 



Crude Oil Emulsion is employed as the 

 stock contact poison against sucking 

 insects (Scale-bugs, Aphides, etc.), but — 

 according to the author — may be replaced 

 to advantage by ' Virmisapon ' — an in- 

 secticide made locally in accordance with 

 Mr. Lefroy's suggestions and advice, 

 and placed on the Indian market to 

 supply the demand for a cheap and 

 effective ready-made remedy. 



The author draws attention to the use 

 of deterrents, where the employment 

 of an actual insecticide is impracticable 

 or inadvisable. The object of a ' deter- 

 rent ' is to render the plant unpalatable. 

 It may be of considerable service in 

 preventing the spread of a localized 



