74 



ZOOLOGY 



do the latter multiply that were it not for the voracious larvae 

 of the ladybird, most plants would be destroyed in a single 

 season. The larvae of the ladybirds are dark, spotted, and 

 hairy. The elytra of the imago are in 

 most species reddish in color. 



The list of beetles directlj' or indirectly 

 useful to man is small. The carrion- 

 beetles, tuml)le-bugs, and rove-beetles, 

 which feed upon decaying animal and 

 vegetable matter, are useful as scavengers. 

 Of those which serve us bj^ killing other 

 insects injurious to vegetation, the lady- 

 bird beetle stands first. The economic 

 importance to us of this one familj' can 

 hardly be estimated. Different kinds of 

 ladybirds feed on different species of in- 

 sects. At one time it seemed that the 

 orange industry, if not that of fruits in 

 general, was doomed in California on ac- 

 count of the destruction wrought l:)y the 

 introduction of a scale-insect. As the 

 insect had been imported, we had no 

 native beetle which attacked. Search 

 was made abroad, and a ladj'liird beetle 

 was found in Australia which feeds on 

 this particular scale-insect. The Austrahan beetle was intro- 

 duced into California, and now the scale-insect is subdued. 

 The larvae of some of the checkered beetles ^ feed upon the 

 larvffi of boring beetles, while the larvae of tiger-beetles watch 



Fig. si. — Cyllfiic robi 

 nee, locust borer. 



' A family of rather small beetles, living in flowers and on trees, and 

 often with contrasting colors. 



