EXPERIMENTS WITH INSECTICIDES UPON POTATOES. 1 89 



FOURTH EXPERIMENT. 

 Statement of Conditions. This experiment differed from No. 

 1 only in that all the plants were first covered with slugs and then 

 very liberally dusted with Bug Death. 



Results : As in the three preceding experiments the slugs as 

 soon as dusted started for the under side of the leaves and within 

 an hour not a slug was left on the surface of the leaves. 



After 6 hours a few dead slugs were found under the plants. 

 Several had already started to escape. 



After 22 hours several more dead slugs were found under the 

 plants. Nearly one-half of the slugs had made good their escape 

 by forcing themselves under the netting. 



After 28 hours the number of the remaining slugs was some- 

 what decreased. The semi-stupor noticed in the corresponding 

 observations of experiments Nos. I, 2, 3, was also here slightly 

 noticeable. 



After 52 hours no change was noticeable. The few remaining 

 slugs were feeding on the under side of the lower leaves. 



After 68 hours only two slugs were remaining on the plants, 

 and these were feeding on the basal leaves. The slugs showed 

 no sign of any stupor. 



During the three following days no observation worthy of 

 record was made and so the experiment was discontinued. 



Summary of the results. The effect most noticeable upon the 

 bugs from the application of the Bug Death is its great driving 

 property. The principle exodus of the slugs took place during 

 the first night, and the subsequent escapings were also mostly 

 made at flight. 



In the four experiments in the observations which took place 

 after 28 hours, a semi-stupified condition was quite noticeable. 

 The slugs would hang onto the under side of the leaves slightly 

 curled up, apparently dead. When knocked to the ground they 

 would slowly uncurl themselves and perhaps in an hour or so 

 would be back again on the plants or more likely they would have 

 made their escape under the netting. During the next forty-five 

 hours there was an apparently complete recovery from the stupe- 

 faction. Only a small number of slugs were killed by the Bug 

 Death. Whether these were killed by suffocation from the appli- 



