THE GREENHOUSE THRIPS. 



55 



Experiment No. 9. — Ma}' 26, at 7 p. m., fumigated with one-half 

 sheet of aphis punk (fresh box). Fumigation histed all night. The 

 sky was cloudy. 



Mav 27, the plant was uninjured. The condition of the thrips was 

 as follows: 



Experiment No. 10. — May 20. at 5.50 p. m., fumigated with nico- 

 fume liquid (1 tablespoonf ul = J ounce + 1 ounce water, vaporized 

 over an alcohol lamp) . The sky was partly cloudy. Sprinkled the 

 plant with water. 



The vapor rose slowly until G p. m., when small flies cm the window 

 began to drop. House flies were stfll flying around tlie room at 6.15 

 p. m., when the liquid was all evaporated. 



May 21, the plant was uninjured. Red spiders were apparently 

 all alive. A very careful examination of the plant failed to show a 

 live thrips. 



Experiment No. 11. — May 27, at 3.50 p. m., fumigated with nico- 

 fume liquid (Hablespoonful to 2 tablespoonfuls of water, vaporized). 

 Sky clouded, breeze strong. 



May 28, the plant was uninjured. 



Experiment No. 12. — May 21, at 6 p. m., fumigated with rose-leaf 

 insecticide (29 c. c. + 25 c. c. water, vaporized over an alcohol lamp). 

 The sky was cloudy, wilh rain faUing. 



May 22, the plants were apparently uninjured. Red spiders were 

 alive. 



