THEIR RELATION TO EACH OTHER 107 



And so we have in these CoccinelUd beetles a series 

 of the most highly important checks to some of the 

 most destructive insect types, the removal of which 

 would cause a serious derangement of conditions as 



Fig. 49. — Chilocoriis sumhs. a beetle laying egg under scale; b, c scales 

 awing egg in place; d. egg m scale, e. egg. /, eggs under bark flap, g, same, 

 tural size; /z, j, young larvae, ;, same feedmg. 



show 

 natura 



they at present exist. These checks are flexible within 

 limits, and automatically, by simply devouring each 

 other, restore themselves to inconspicuous numbers 

 when their services are no longer needed. But we are 

 not yet in position to train them to our service nor to 

 induce them to feed on unfamiliar species. 



