Tl 



THE BEETLES: COLEOPTERA 41 



Fig. 24), are hemispherical in shape and generally reddish or 

 yellowish in color, with black spots. Both the imagoes and 

 larvae of most species feed upon plant- 

 lice and other insects injurious to vege- 

 tation ; hence they are to be reckoned 

 among the insects useful to the farmer. 

 A few years ago, when the orange- 

 growing industry of California was 

 threatened with great loss, if not total 

 extinction, from the attacks of a scale- 

 insect, an Australian lady-beetle (Veda'- 

 lia) was introduced to feed upon it. 

 The success of the experiment was so 

 great that large sums have been saved 

 to the orange-growers. Another scale- F IG . 24. Lady-Beetle. 

 insect, the San Jose scale (Aspidio'tus 



pernicio'sus), so called because it first appeared many years 

 ago in that city, has since spread widely over the country, 

 causing great damage to the orchard interests. Investiga- 

 tions set on foot by the Division of Entomology of the United 

 States Department of Agriculture located the original home 

 of the insect in China, and the discovery was made there 

 of a lady-beetle (Chiloc'orus sim'ilis) which preys upon it. 

 This lady-beetle has now been introduced and distributed to 

 infested regions, with every prospect of success. 



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 



