June, '17] LOVETT: NICOTINE AN INSECT POISON 335 



Experiment C. 

 May 5, 1916. 

 Sprayed apple foliage with following: 

 No. 3, Black Leaf 40, 1-800 

 No. 4, Black Leaf 40, 1-1200 



Thoroughly covered foliage with fine misty spray and allowed to 

 drj^ for six hours. Placed approximately 1,000 half -mature tent cater- 

 pillars on each. 



The results were practically identical with those of Experiments A 

 and B with the immature forms. The material was apparently very 

 repulsive, though no odor of nicotine could be detected. The fohage 

 was placed where a breeze could blow across it. The caterpillars 

 continued to act restless, dropped, writhed and spewed. The effect 

 of the spray on these larger forms was slower. Also, more caterpillars 

 were used in the tests. Dailj^ observations were made up until May 

 19, a total of 14 days, when approximately all had left the sprayed 

 fohage. Each day a number would drop, lie for approximately three 

 hours as though dead, then recover and crawl away. Those which 

 crawled away collected in a mass on the sill of the window. On May 

 10 and 11 these forms were collected and placed on fresh unsprayed 

 foliage. Here they fed with great gusto and apparently showed no ill 

 effects of the recent illness. On May 11, two caterpillars were found 

 dead on No. 3; the foliage showed small feeding punctures. There 

 were three dead on No. 4, which also showed sUght evidence of feeding. 

 The foliage was changed on May 12, first allowing it to dry thoroughly 

 after applying the spray. On May 19, seven caterpillars were dead 

 under No. 3 and 12 under No. 4. Feeding for the entire period 

 amounted to a total of about two fair-sized leaves. 



Experiment D. 



May 19. 



Dipped camel's hair brushes in Nicotine Sulphate 40 per cent and 

 treated nearly mature caterpillars as follows: 



No. 1. Black Leaf 40, 1-800, painted ventral surfaces of 10 caterpillars with 

 moist brush and then placed caterpillars on fresh unsprayed apple foliage. 



No. 2. Pratt's Nicotine 40, 1-800, allowed brush to dry for 24 hours, painted 

 ventral surface of 10 caterpillars and placed on fresh unsprayed apple foliage. 



No. 3. Black Leaf 40, 1-1200, allowed to dry 24 hours and treated as above. 



No. 4. Pratt's Nicotine 40, 1-1200 treated as No. 1. 



No. 1 and No. 4 nauseated, spewed up and dropped off; eventually 

 recovered. 



No. 2 and No. 3 restless for a time but eventually commenced feed- 

 ing and were apparently normal. Not sick. 



