100 THE CANADIAN IIOKTICULTURIST, 



In our window-gardens and greenhouses, however, we cannot rely 

 upon the Ladybirds to rid us of the Aphis. They increase with such 

 marvellous fecundity, and do their work of destruction so rapidly upon 

 the tender indoor growth, that some measures must be taken to arrest 

 them in their work of destruction more prompt and more sweeping 

 than the vbracity of the Ladybird. Hence in greenhouses recourse is 

 had to fumigation. The ventilators are carefully closed, and every 

 opening through which the smoke can rapidly escape is stopped, and 

 the smoke made to remain among the plants until the Aphis succumb 

 to the poison of the tobacco. This work of smoking them to death 

 with the fumes of tobacco is comparatively easy in our greenhouses, 

 but is very troublesome and inconvenient in the case of house plants. 

 No tidy housekeeper wants to have her rooms filled with the odor of 

 tobacco smoke every few days, until her house has the fragrance of a 

 bar room. And the expedient of substituting sulphur for tobacco, 

 which was tried by a lady correspondent of one of our horticultural 

 exchanges, is one that will never be attempted a second time, for 

 though it may kill the insects, it will also kill the plants. 



Some remedy for the Aphis on our house plants, less objectionable 

 than tobacco smoke, has been long sought for, and many expedients 

 resorted to, but none of them have been quite satisfactory. Of late 

 years it has been ascertained that the powdered flowers of the Dal- 

 matian Pyrethrum are very energetic insecticides, and that either whole 

 or powdered they retain this quality for a number of years. The 

 attention of housekeepers has within a short time been drawn to this 

 powder as a means of killing house flies, cockroaches and fleas, which 

 sometimes become very troublesome, and small blowers or bellows 

 have been made and sold for diffusing the powder and scattering it as 

 dust in the air so as to kill these insects. Finding that our house flies 

 were easily killed by this powder, experiments were made upon the 

 Aphis, which were infesting some scented geraniums, and to our great 

 pleasure they were shortly after found strewing the ground under the 

 planet, like the wounded and slain on a field of battle. 



Our entomological friend, W. Saunders, of London, has given in the 

 Entomologist for March an account of his experiments with this insect 

 powder. His trials were made in a greenhouse where they seem to 

 have been very abundant, the air of which he freely charged with fine 

 clouds of the dust of this insect powder, and found that the Aphis soon 



