Useful Insects 179 



247. Lady Bugs are another class of insect-eating 

 insects. They feed on eggs of the Colorado potato bugs, 

 and on plant-lice. The larger forms are easily recog- 

 nized by their red and black-spotted color. Two im- 

 portant kinds of lady bugs are pictured in Fig. 114. 

 One species, Megilla maculata (Fig. 114), is especially 

 active in feeding on the green bug on grains, while 

 another, Hippodamia convergens, is more active on the 

 plant-lice on cotton and melons. The latter will lay 

 about fifteen eggs per 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 aphids 

 per day. We recognize these insects as a benefit to man- 

 kind in various ways. 



248. Parasitic Insects are possibly the most import- 

 ant class of beneficial insects. Without them, the 

 locusts or grasshoppers, the caterpillars of butter- 

 flies and moths, and many other kinds, would destroy 

 all the plants. Every farm in extreme southern regions 

 should have a "lady bug patch." They require plenty 

 of insect food for rapid multiplication 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 parasite, the cabbage 

 aphis. The lady bugs, thus having food through the 

 winter, grow and multiply until spring when food natur- 

 ally becomes abundant. 



