THE CANADIAN HORTICULTURIST. 101 



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liegan to manifest symptoms of uneasiness and to drop to the ground, 

 and after the lapse of a couple of hours the greater portion of them 

 Avere lying upon the ground or the shelves or floor. Mr. Saunders is 

 led to believe that they are not killed outright by the powder, but that 

 they are so stupefied or paralized that they fall, and are unable again 

 to return to the plants, and so eventually perish. 



These experiments seem to indicate that we have in this Dalmatian 

 Pyrethrum powder a very valuable means of ridding our house plants 

 of the Aphis; one that can be easily applied, and at any time, without 

 the inconvenience arising from tobacco smoke. In what way the 

 l)0wder acts upon them seems not yet to have been ascertained, some 

 attributing the effect to a volatile oil contained in the flowers, others to 

 an alkaloid. It is not at all necessary to throw the powder directly 

 upon the insects, but merely to fill the air of the room with a cloud of 

 the dust and close it for a few hours, when the flies of your dining-roora 

 and the Aphis on the window plants will be found killed or paralized 

 by its mysterious power. 



Mr. Saunders states that the powder made from the flowers of 

 Pyrethrum roseum and carneum, sold under the name of Persian 

 Insect Powder, though a good insecticide, is not as energetic in its 

 action as the powdered flowers of the Pyrethrum cinerarise folium, 

 know as the Dalmatian Insect Powder, the plant being a native of 

 Dalmatia, Austria. The Dalmatian Powder commands a higher price 

 than the Persian on account of its greater efficiency, yet notwithstanding 

 the price, is to be chosen in preference to the other. 



HOETICULTUEAL GOSSIP. (VIII.) 



BY L. WOOLVERTON, M. A., GRIMSBY. 



ApMs mali {Fdbr.) Our apple orchards are swarming with plant 

 lice. A few days ago we were exulting over the unprecedented show 

 of fruit blossoms, even upon apple trees that bore heavily last year ; 

 and we were just congratulating over the almost complete disappear- 

 ance of the Canker Worm, which for three or four years has been our 

 worst enemy; when lo! these tiny insects of a hated race {Hemiptera) 

 were discovered on every leaf and fruit blossom in countless numbers 

 as busy as they could be, sucking the juices from the tender growth, 

 and multiplying with terrible rapidity. 



