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JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



While in many cases — perhaps the majority — excellent results have 

 been obtained by the application of either one of these two measures, 

 nevertheless, it frequently occurred that such results proved entirely 

 unsatisfactory. This has been the case occasionally, even when these 

 poisons were being used in the hands of expert entomologists. It has, 

 therefore, for some time, appeared desirable that investigations be 

 taken up with a view to discovering the determining factor in such 

 failures, as they could not, in all cases at least, be attributed to lack 

 of care in preparing and applying these mixtures. 



In fact, very often farmers expected to get results in a few hours, 

 whereas the full effects of the poisons have been found by all of the 

 men conducting these experiments to extend over three or four days' 

 time. 



With this situation in mind, experiments were undertaken by four 

 of the cereal and forage insect field stations which together covered a 

 territory extending somewhat interruptedly from the Atlantic to the 

 Pacific coasts. 



For upwards of forty years there have been periodical outbreaks of 

 several species of grasshoppers in the Merrimac and Connecticut 

 River valleys in New England, originating in the intervales along the 

 river bottoms. At no time have these outbreaks been satisfactorily con- 

 trolled and they have, in the past, cost the farmers located in these 

 valleys, immense sums of money. It was with a view to establishing 

 a systematic piece of investigational work that the writer made a sur- 

 vey of the Merrimac valley during the summer of 1914. 



The particular species of grasshoppers involved in these New 

 England outbreaks were Melanoplus atlanis, Melanoplus bivittatus, 

 Melanoplus minor, and Camnula pellucida, besides one or two other 

 less important species. 



With a view of determining whether or not it was possible to control 

 these outbreaks, Mr. Harrison E. Smith was detailed to take up the 

 work in New England, and carry it on during the spring and summer of 

 1915. One of the first obstacles to be encountered was the rather 

 surprising fact that the young grasshoppers were much more difficult 

 to kill with the poison baits than were those fully developed. The 

 doubling of the amount of fruit used in the poison bran mixture, and 

 adding that ordinarily used in this mixture to the Griddle mixture, 

 eliminated this difficulty to a considerable extent, as the baits with 

 the additional fruit appeared to be more attractive to the young grass- 

 hoppers. Still, there were failures even in cases where these poisons 

 were used against full-grown insects, and even now the young up to 

 the third instar do not seem to yield readily to these baits even with 

 the increased amount of fruit and double the amount of the bait ap- 



