THE INSECTS: HEXAPODA 89 



States live on farms. When it is considered that our crops 

 are attacked not by one but often by many different insects, 

 and that, according to the estimate of one of the state ento- 

 mologists of New York, there is no crop cultivated which 

 infesting insects do not diminish by at least one tenth, it is 

 plain that the economic relations of insects to agriculture are 

 extremely important. Nearly every order has its injurious 

 forms. Thus the Orthoptera has its locusts ; the Hemiptera, 

 the plant-bugs and aphids; the Coleoptera, the wireworms 

 and leaf-beetles ; the Diptera, 

 various flies ; while almost the 

 whole army of the larvae of the 

 Lepidoptera feed on plants. 



The story of the introduction 

 and spread of the gypsy-moth 

 of Europe (Porthet'ria dis'par, FlG . 61 . Gypsy-Moth. Natural size. 

 Fig. 51) in Massachusetts, (After Howard, Bulletin No. ll,x.s., 

 teaches an important lesson. Umted States Department of Agri- 



1 culture, Division of Entomology) 



This insect, long well known 



by European foresters as destructive, was probably introduced 

 in 1869 by a professor connected with Harvard Observa- 

 tory, who was interested in breeding silk-producing insects. 

 The larvae escaped into his garden at Medford, near Boston, 

 and though search was made for them, not all were found. 

 Nothing was heard from them for fifteen years, when they 

 began to be troublesome in gardens. By 1889 they had mul- 

 tiplied to such an extent that they attacked every green thing, 

 and the bare branches of trees in every direction gave evi- 

 dence of the extent of the devastations. In this year the 

 insect was identified. Up to that time it had been called 

 simply " the caterpillar." First the town of Medford, and 

 then the state, took up the matter, and the first state appro- 

 priation of twenty-five thousand dollars was passed. Since 

 that time additional appropriations have been called for, till 



