342 BOARD OF AGRICULTURE. 



held under the vines a short time every evening while the 

 grapes are forming. It is certainly offensive to them, and if 

 used carefully need not injure the plant. 



Rose Slugs. — This insect is easily destroyed by spraying 

 with water and pyrethrum, at a rate of one tablespoonful of 

 the latter to a pailful of the former. 



Letters. — Several letters have been received asking for 

 information in regard to insects and fungus injurious to 

 plants, which have been answered by letter, and for general 

 information we insert the answers of a few of them. 



Letter No. 1, containing shoots of the apple tree covered 

 with a coatino; of black masses containins; some fundus 

 growth. These black masses are the result of dust adhering: 

 to the shoots made sticky by the exudations of the common 

 apple aphis or plant louse, which were unusually abundant 

 the past two seasons and caused great injury to young trees. 

 The remedy is to syringe with strong soapsuds, or with a 

 tablespoonful of pyrethrum in a pail of water. 



Letter No. 2, containing twigs of the jDcach tree in which 

 were found a double row of the eggs of the tree cricket 

 ( Oecanthus niveus) . This insect lays its eggs more com- 

 monly in the branches of the raspberry and blackberry, but 

 in some cases in those of the peach and plum. The larvse, 

 after hatching, leave the twigs and for a time feed upon plant 

 lice, and later in the season upon succulent ripe fruits. The 

 tree cricket is light green in color, and when full grown is 

 about three-fourths of an inch long, and lays its eggs in 

 autumn in the centre of the shoots in long lines, as men- 

 tioned above. 



3. Ox THE CAtrsES OF Certain Diseases of Grasses. 



June Grass and White Top. — To this grass, on account 

 of the many inflorescences that fall to mature and turn white, 

 is often given the name of icldte top, and the question is 

 often asked, " What is the cause of this condition?" Upon 

 careful investigation it has been found that this condition is 

 most prevalent upon land exhausted by long cropping, or 

 where the roots have been much injured by the larvce of the 

 June bug or May beetle. The turning of the top to a white 

 color is due to the destruction of the culm or stalk, just above 



