Useful Insects 177 



day, and often a total of 500 eggs. These are deposited 

 on leaves in clusters of from a few to fifty in a place. 

 A lady bug will eat about fifty aphis per day. We recog- 

 nize these insects as a benefit to mankind in various 

 ways. 



248. Parasitic Insects are possibly the most import- 

 ant class of beneficial insects. Without them, the 

 locusts and grasshoppers, the caterpillars of butter- 

 flies and moths, and many other kinds would destroy 

 all the plants. Every farm should have a "lady bug 

 patch." Unless these insects have food during the 

 winter months, they die. They require plenty of insect 

 food, and this should be provided by growing some crop 

 that harbors insects through the winter. Some winter- 

 growing plant, like rape which has a winter insect para- 

 site, the cabbage aphis. The lady bugs, thus having 

 food through the winter, grow and multiply until spring 

 when food naturally becomes abundant. 



