544 



SCIENCE. 



[N. S. Vol. IV. No. 94. 



last century. It is undoubtedly true that 

 the great advances made in the system- 

 atic study of insects during the last half of 

 the 18th century, by Linngeus, Fabricius, 

 Denis and Schiflfermiller, Esper, Herbst, 

 Schrank, Illiger, Scopoli, Latreille, Eosel, 

 Panzer, Olivier and a host of others, gave a 

 great impetus to economic entomology, as 

 shown by the remarkable work of Bechstein 

 on ^ Forest Insects,' published in 1804-5 ; 

 ' Hints to the Proprietors of Orchards,' by 

 Salisbury, published in London in 1816 ; 

 Kollar's ' Insects Injurious to Farmers and 

 Gardeners,' published in 1836 ; Eatzeburg's 

 '■ Forest Insects,' published in 1840, with 

 many others in Europe ; while in this coun- 

 try there were numerous essays on injurious 

 insects and methods of destroying or hold- 

 ing them in check, published in the early 

 part of this century. Harris published nu- 

 merous papers on economic entomology in 

 the New England Farmer, beginning as early 

 as 1823, but his classic work on the ' In- 

 sects of Massachusetts Injurious to Vegeta- 

 tion ' appeared near the end of 1841. Fitch 

 published his first ' Eeport on the Insects of 

 New York ' in 1855, and this was followed 

 by thirteen others. Townend Glover began 

 his work in economic entomology in 1854, 

 from the smallest beginnings, and we can 

 scarcely realize that in forty years the divis- 

 ion of entomology, under the leadership of 

 such brilliant men as Eiley, Comstock and 

 Howard, with their able assistants, should 

 now be giving to the world such masterly re- 

 ports as emanate from that center. 



It is not my intention, however, to speak 

 so much of the men as of the development 

 of methods in economic entomology. The 

 entomologists of the present century have 

 given us rational methods for combating 

 insects ; methods based on a more or less 

 complete knowledge of the entire life his- 

 tory of the different species of which they 

 treated, with their natural enemies and the 

 best artificial means for their destruction 



that their ingenuities could devise. It was 

 sometime in the sixth decade of this century 

 that arsenical compounds were proposed. 

 There was bitter opposition to the use of 

 these insecticides for a long time, and the 

 reports of cases of poisoning, which were 

 said to have occurred at that time, were 

 startling in the extreme. It was even 

 claimed that potatoes would absorb the 

 poison to such an extent that the tubers 

 would carry poisonous doses, so that after 

 each meal it would be necessary to take an 

 antidote to the poison. There is something 

 in the human mind that leads it to accept 

 the dreadful more readily than the prosaic, 

 and as many believed the fabulous stories 

 so widely circulated at that time, and for a 

 long time after the advent of the beetle into 

 the extreme east of this country, it was a 

 common thing to see large fields of potatoes 

 with persons of all ages and both sexes, each 

 carrying a pan and stick with which they 

 knocked the potato beetles off into the pan. 

 Little by little, however, one farmer after 

 another abandoned the ' stick and pan ' 

 method and adopted the use of Paris green, 

 till it came into very general use. This 

 seemed to give it popularity and there de- 

 veloped a readiness to use any kind of sub- 

 stance that bore the name of insect poison, 

 till now the market is well stocked with a 

 great variety of substances which are 

 claimed to kill all kinds of insects. Lon- 

 don purple followed closely in the wake of 

 Paris green, and kerosene emulsion has also 

 come into great favor for the destruction of 

 the sucking insects, or such as do not eat 

 the entire substance of the leaf. Thus we 

 have several excellent insecticides which 

 are in such general use that we may call 

 the latter half of this century the period of 

 insecticides. 



There were men in the past ages who 

 were far ahead of their times in economic 

 entomology as well as in other departments 

 of human knowledge. J. C. Schaeffer, in 



