MAN'S CONQUEST OF NATURE 585 



shores. During the war of the Anicrican Revolution, these stowaways 

 began to arrive. Witness the Hessian fly cocoons brought in with 

 straw imported from Germany to feed the horses of the Hessian 

 troops. The progeny of these flies, by destroying wheat, have done 

 more damage in this country than all the Hessians who fought during 

 the war. One of the most recent importations and serious pests is 

 the Japanese beetle. Introduced in the soil around the roots of 

 iris plants imported from Japan, it was first observed in New Jersey 

 in 1916. At the present writing it has spread over 300 miles from 

 the point of its introduction and has become a very serious menace 

 over several thousand square miles of territory. The Mediterranean 

 fruit-fly, since its discovery in Spain in 1842, has spread to all parts 

 of the world, gaining a foothold in Florida in April, 1929. Because 

 this fly breeds in citrus and other fruits, as well as in peppers, 

 tomatoes, lima beans, and eggplants, its introduction was a seri- 

 ous menace to the crops of this region. The situation called for 

 strong action in which the state of Florida and the national govern- 

 ment took immediate part. A quarantine was declared and no 

 fruit shipped from the infected area. All trees, vines, or plants on 

 which the flies fed were destroyed, and trees in nearby areas 

 thoroughly sprayed at frequent intervals. This treatment was so 

 effective that by November 16, 1930, no flies or infected fruits or 

 vegetables being found, the quarantine was lifted. But we are not 

 always as fortunate with imported pests. Take, for example, the 

 European corn borer. Because of the nocturnal habit of the moth, 

 which produces the caterpillar, it was not discovered in this coun- 

 try until it was too late to combat it effectually. Now, as the map 

 published by the Department of Agriculture shows, it has spread 

 widely over the entire northeastern part of the United States and is 

 rapidly approaching the corn belt. The story of the incredibly rapid 

 increase of some of these insect pests is repeated again and again. 

 Our cereal crops are attacked at every stage of their existence. 

 Weevils destroy the stored grain, cutworms attack the plants in 

 their early stages, biting insects such as locusts destroy the leaves, 

 and bugs suck the plant juices, while various boring insects such as 

 the corn borer or the codling moth destroy the grain or fruit. 



What is true of food plants is true also of the fiber crops and for- 

 ests of our country. The cotton boll-weevil, imported from Mexico in 

 1892, has spread over the entire South, in some places entirely chang- 

 ing the economic life of the farmer, and causing replacement of the 



