PRACTICAL E]S'TOMOLOGY. 165 



the leaf; they hatch in a few days and commence eating the leaf: 

 when full grown they descend into the 'earth and undergo the trans- 

 formation into the perfect insect ; there are several broods in a year 

 but the later ones remain in the ground all winter and come forth 

 flies in the spring. Syringing the bushes with water heated to 140 

 degrees will destroy the caterpillar or worm without hurting the 

 bushes. Slacked lime scattered on the bushes when the dew is on is 

 a good remedy. 



Onion fly or maggot, {A?it/iomyia ceparum.) It is about half 

 the size of the house fly, of an ash gray color, wings clear and trans- 

 parent. It lays its eggs on the leaves of the onion near the earth 

 which hatch in a week or two, when the maggot descends to the 

 base of the onion where it feeds and the onion soon becomes rotten. 

 It then deserts the bulb, enters the ground, becomes a pupa, from 

 which the perfect insect or fly emerges in three weeks. The fly lays 

 again, dies, and the last eggs hatch and the brood passes the winter 

 in the pupa state. It is difficult to destroy them they are so small 

 and prolific. Among the methods recommended are strewing the 

 beds with charcoal, soot or* salt, watering with lime water, gas 

 tar, urine, soap suds &c. A good idea is to plant in a different 

 place each year. 



Thrips {Tkrips ) This is a tribe of minute and very active in- 

 sects that prey upon grain, potatoes, peach trees &c. It is said 

 there is a mite or ichneumon that preys upon them preventing their 

 increase. 



The apple bark louse, {Aspldiotiis conchifoi^mis.^ About one 

 eighth of an inch long, oval, brown color, called "oyster shaped 

 louse." It sucks the juice of the tree to which it adheres. It in- 

 fests the apple, currant, rose and butternut. It lays its eggs upon 

 the tree and dies, covering the eggs with its body, from which the 

 maggots come and spread over the tree. Tar and linseed oil beat 

 together and applied with a brush to the afiected parts of the tree 

 before the buds expand in spring, is said to destroy the eggs concealed 

 under the scales. The insects live only a short time, in June, ap- 

 pearing like minute specks of mould, and are then very easily 

 destroyed by washing the bark with soap suds. 



Plant lice {Aphides.^ This is a numerous class of minute in- 

 sects, some winged, of all shapes and colors. They suck out and 

 12 



