8 



and during rain. These times are preferable to any other part of the day, because 

 coolness and humidity cause insects to collect together, and then they form heaps 

 which may be crushed at once. If, moreover, they have gained the top and the 

 height prevents their being reached with the hand, the tree must be shaken, or a 

 pole with rags on the end of it employed to sweep them off. But expedients must 

 be suggested by circumstances. Another snare, the success of which is not less 

 happy, for securing fruit trees is to lay the trunk over with glue, etc. 



This represents fairly well the status of economic entomology at the 

 end of the last century. It is undoubtedly true that the great ad- 

 vances made in the systematic study of insects during the last half of 

 the eighteenth century by Linnaeus, Fabricius, Denis, and Schiffer- 

 miiller, Esper, Herbst, Schrank, Illiger, Scopoli, Latreille, Eosel, Pan- 

 zer, 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; Koliar's Insects Injurious 

 to Farmers and Gardeners, published in 1836; Eatzeburg's Forest In- 

 sects, 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 holding them in check published in the early part of 

 this century. Harris published numerous papers on economic ento- 

 mology in the New England Farmer, beginning as early as 1823, but 

 his classic work on the Insects 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 Division of Entomology under the leadership of such 

 brilliant men as Eiley, Comstock, and Howard, with their able assist- 

 ants, should now be giving to the world such masterly reports as ema- 

 nate 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 entomolo- 

 gists of the present century have given us rational methods for com- 

 bating insects — methods based on a more or less complete knowledge 

 of the entire life history 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 some time in 

 the sixth decade of this century that arsenical compounds were pro- 

 posed. 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 for 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 



