INJURIOUS INSECTS. 99 



of the food plants, where the larvae do some damage; in other 

 cases the eggs are laid on the under side cf the leaves and the 

 larvae mine into them and live between the upper and lower 

 surfaces. But their chief damage is as beetles, in which form 

 they pass the winter. One species of flea beetle is sometimes 

 destructive to potato vines. 



Figure 43. — Different species of flea beetles with their larvae. 



Remedies. — Since thcSe are biting insects they are readily 

 killed by Paris green or London purple in the usual propor- 

 tions. If the plants are kept dusted with air slaked lime or 

 plaster they are measurably protected from this insect. But the 

 latter applications are greatly improved by adding a little poison 

 to them. 



Leaf Lice or Aphides (Aphis sp.) — The various kinds of 

 leaf lice, otherwise called aphides, that live on plants have very 

 much the same general habits. They are all sucking insects and 

 increase with great rapidity when their food plants are abund- 



Lof C. 



