264 Insects and Sprays 



the death of many of them. Here, again, caution 

 should be exercised that the poison may not come 

 in contact with children or with adults who are 

 ignorant of its presence. 



When a greenhouse has been infected with insects 

 all good plants should be taken out and the house 

 thoroughly disinfected. Burning six ounces of 

 sulphur to every one thousand cubic feet of space 

 and keeping the house tightly closed for twenty- 

 four hours will destroy any insects. Any plants 

 infected should be destroyed, and this can be done 

 by leaving them in the greenhouse when the dis- 

 infecting is being done. 



Hydrocyanic gas is a most dangerous fumigant 

 and should never be used except by experts. 



Tobacco extract can be procured at almost any 

 dealer's and is safe and satisfactory to use as a dis- 

 infectant. It should be burned once every spring 

 in the greenhouse as it is very effective in destroying 

 plant lice. The plants should be taken out first. 



The mealy-bug is a soft, white bug with a cottony 

 appearance. It usually attacks plants which have 

 soft wood stems and the plants should be sprayed 

 with kerosene emulsion. (See index.) 



