30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



robenzene is scattered on top of the stacks and suspended in bags 

 from the roofs of the sheds. 



Carpet beetles, also called " buffalo moths," often do considerable 

 damage to carpets, woolens, furs, feathers, and upholstered furniture. 

 One of the control measures is to prevent them from coming in con- 

 tact with these articles by using repellents, such as naphthalene in 

 the form of flakes and moth balls, paradichlorobenzene, or camphor, 

 or by the use of red cedar chests. 



2. ORIGINAL WORK ON MEXICAN BEAN BEETLE 



In 1928, Mr. J. E. Graf, Assistant Chief of the Bureau of Ento- 

 mology, handed the writer a manuscript entitled " Some chemotropic 

 responses of the Mexican bean beetle," by Wallace Colman, who tested 

 over 200 materials, but found only a few to be attractive while a 

 larger number were repellent. According to the results in this un- 

 published manuscript, which deals with the sense of smell alone, the 

 following seemed to be attractive : banana peel, amyl acetate, vanillin, 

 coumarin, corn sirup, honey, and molasses of the higher grades ; while 

 certain lead and arsenic compounds, including lead arsenate, seemed 

 to be repellent. Using different methods the present writer tested 

 all of the above supposed attractants, but found only the corn sirup 

 and molasses to be attractive, while lead arsenate proved to be re- 

 pellent. 



(a) search for attractants and repellents, using an olfactometer 



Using the writer's (45) olfactometer, with the plant chamber dis- 

 connected, no important results were obtained, but the following re- 

 marks may have some theoretical interest. On several occasions fresh 

 bean leaves were put in the small bottle, used for holding the odorous 

 substance to be tested. In each test in which only a few leaves were 

 used the odor or exhalation from the leaves was attractive to the 

 bean beetles, although the highest attraction was only 57.9 per cent. 

 In two other tests the bottle was filled full of leaves. The results 

 (61.8 per cent and 72.5 per cent), instead of showing attraction, 

 showed repulsion, indicating that attractants when concentrated be- 

 come repellents. The odors from tabic molasses (i part molasses and 

 I part water) and the water extract (diluted juice) of bean leaves 

 were also found to be slightly attractive. 



The following, used in minute quantities, were reix^llent: oil of 

 peppermint, creosotum, nicotine sulphate, banana peel, amyl acetate, 

 and geraniol. 



