April, '15] 



ENTOMOLOGISTS' PROCEEDINGS 



229 



average square yard contained 26 dead grasshoppers, another one 64. 

 Five days after the bait was distributed, sick grasshoppers were still 

 to be seen, though there had been a heavy two-hour rain the day before 

 and the eJQ&ciency of the mash was therefore probably decreased. The 

 next day it was estimated that over .9 of all the grasshoppers originally 

 in the field had been destroyed, and at the end of a ten-day period the 

 fatalities approached 99 per cent. The cost of the materials was 

 estimated at 13 cents per acre. Observations lead us to believe that 

 the wider the distribution the more effective the results. This poison 

 was not only tested in fields where grasshoppers were abundant and 

 consequently had destroyed much of the more succulent vegetation, 

 such as the new seeding and the younger leaves of the grain, but it was 

 also used in several oat fields where there had been practically no 

 injury and the new seeding was therefore thrifty and luscious. Even 

 under such apparently adverse conditions, so far as efficiency of the 

 poison is concerned, the insects freely ate the poisoned bait and suc- 

 cumbed before they were able to cause any material injury. The 

 Criddle mixture was used by some farmers with, almost equally good 

 results though it is not nearly so easy to prepare. The experience of 

 last summer also showed the advisability of protecting the nostrils 

 with a moistened sponge and the avoiding of the poisoned du^t so far 

 as practical in the case of parties who are required to mix large v-^uanti- 

 ties of the poison. There is a source of danger here which should be 

 safeguarded against at the outset, otherwise serious results might 

 follow. 



We were unable to learn of any deleterious effects resulting from the 

 use of this material when, ordinary precautions were observed. The 

 moist sweetened bran is very attractive to domestic animals and 

 therefore great care should be exercised to prevent their gaining access 

 to containers used for mixing or distributing the material. We dis- 

 tinctly ad\ise against putting out the poison in small spoonfuls or 

 masses, partly because there is greater danger of poisoning domestic 

 animals, and also on account of the increased efficiency accompanying 

 a sparse distribution. Undermost conditions we would expect prac- 

 tical immunity from grasshopper injury following one application of 

 the bait, even though the grasshoppers were allowed to remain unmo- 

 lested in badly infested adjacent fields. 



Mr. S. J. Hunter: Regarding the effects on the nostrils of the 

 workers, it appears that Dr. Felt has found it about the same as we 

 have in the west, where mixing such large quantities, our workers found 

 it desirable to use gasohne propelled cement mixers. When issued, 



