INSECT ENEMIES. 



^ 



(See figure 70.) The numerous punctures they make 

 in the bark of the tender shoots produce warts or ex- 

 crescences on the bark, till the limbs become sickly, the 

 leaves turn yellow and drop off, and sometimes the whole 

 tree dies. 



Remedies. The lady-bugs and their larvae, the larvae 

 of the Syrphus and lace-winged flies, and the little chal- 

 cid fly (Aplielinus mali, Hald.),all feed on these plant- 

 lice. The old bark should be scraped off wherever it 

 makes a harbor for them, and then with a stiff brush 

 they should be treated to a solution of lime and sulphur 

 (five pounds of lime to one of sulphur in two gallons of 

 water, heated till the sulphur is dissolved). The earth at 

 the roots, as far as practicable, should be exchanged for 

 fresh soil. A pound .of potash in a gallon of water is 

 effective. Another application is made, melting three 

 ounces of resin with the same quantity of fish oil, and 

 applying it warm with a paint brush. Spiders spin their 

 webs over and feed on them at their leisure. 



4. THE SEVENTEEN-YEAR CICADA, commonly called 

 LOCUST (Cicada septendecim, Linn.). This insect de- 

 rives its name from the time it requires to pass through 

 its several changes. The long intervals at which they 

 appear, and the little damage they do to the quince, make 

 any extended description of the seventeen-year locusts, 

 however interesting, quite unnecessary here. It may be 

 found in any good work on entomology. The damage 

 done by these insects can not be prevented. They can 

 not eat, and the only injury they do above ground is 

 confined to the small branches in which they deposit 

 their eggs ; but when they go over a whole tree in this 

 way it becomes a serious matter. These branches die 

 and fall off, and there is nothing to do but trim off the 

 rough ends with a smooth cut. In the larva state they 

 do much injury to the roots of trees. The birds, poultry, 

 etc., destroy many. The plow destroys more in culti- 



