224 NATURE-STUDY 



locusts, so that often great numbers of them are stricken. The 

 eggs and young of the Mountain Locusts do not thrive well 

 in the lowlands and soon die out. Thus, there are natural 

 checks upon these rapacious hosts. 



Many other kinds of insects are very injurious to the 

 farmer's crops, notably the army-worm, chinch-bug, potato- 

 beetle, cotton-boll weevil, etc. 



Not only the farmer's crops, but his animals as well suffer 

 from insects. There are many species of flies, mosquitoes, 

 gnats, hce, ticks, mange insects etc. that irritate and injure 

 his horses, sheep, and cattle. Poultry also suffers much in 

 the same way. External scabs and internal bot-flies, if 

 neglected, may result in the death of the animals so affected. 

 In South Africa there is a fly called the Tsetse-fly that intro- 

 duces with its bite a disease germ that kills cattle and even 

 man. 



The United States Department of Agriculture, and the 

 Agricultural and Experiment Stations of various states have 

 departments of entomology for the study of harmful insects 

 and ways of controlling them. 



Insects and Flowers 



There exists a very intimate relation between flowers and 

 insects. A few minutes spent in watching a flower-bed or a 

 patch of wild flowers will show flies, bees, bumblebees, moths, 

 and butterflies, as well as other kinds of insects, crawling into 

 or over the flowers, sipping the nectar, or eating and gathering 

 the pollen. These insects are doing a great work in nature — 

 carrying pollen from the stamens to the pistils of the flowers. 

 This is called pollination, and is an essential thing in the for- 

 mation of fruit and seed. It is an interesting fact that if a 



