THE BEETLES: COLEOPTERA 



49 



Fig. 32. Scavenger beetle. (Slightly 

 enlarged) 



other insects injurious to vegetation ; hence they are to 



be reckoned among the insects useful to the farmer. 



The lady beetles are 

 protected by a yellow, 

 odorous fluid formed in 

 the blood. When the 

 insect is seized the fluid 

 oozes out from the ends 

 of the femora. The 

 bright colors of these 

 insects are usually cited 

 as an example of warn- 

 ing coloration. 



Click Beetles. The 

 click beetles are a well- 

 known group, generally brown in color and of elongate form. 



The species are able to leap into the air when placed on 



their backs. The mechanism which 



makes this possible consists of a 



spine projecting backward on the 



ventral surface of the prothorax, 



and a corresponding cavity on the 



ventral surface of the mesothorax. 



The larvae are called wireworms and 



live in decaying wood or attack the 



roots of vegetables. 



Fireflies. The flashing lights of 



the fireflies (Photi'nus) on the first 



warm evenings announce the com- 

 ing of summer. One would scarcely 



accept these soft-bodied insects 



(Fig. 34) as beetles were it not for 



the way in which the outer wings meet down the middle 



of the back in a straight line in true beetle fashion. 



Fig. 33. Lady beetle. (x2) 



