THEIR RELATION TO EACH OTHER 107 



And so we have in these Coccinellid 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. Chilocorus similis: a, beetle laying egg under scale; b, c. scales 

 showing egg in place; d, egg in scale; e, egg; /, eggs under bark flap; g, same, 

 natural size; h, i, young larvae; /, same feeding. 



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. 



