EXPERIMENTS AGAINST BEDBUGS. 



POWDERED MIXTURES CONTAINING MORE THAN ONE ACTIVE INGREDIENT. 



A number of jar tests have been made with 20 miscellaneous pow- 

 ders containing small amounts of nicotine, naphthalene, pyrethrum, 

 and various oils as active ingredients. These powders were more or 

 less effective, depending on the amount of the active ingredients 

 present. 



MISCELLANEOUS MATERIALS. 



The following materials were found to be more or less effective 

 against bedbugs, killing from 80 to 100 per cent in jar tests: 



Miscellaneous materials more or less effective against bedbugs. 



Material. 



Form of preparation. 



Killed. 





50 per cent solution 



Per cent. 

 100 





Undiluted 



80 





....do 



100 





10 per cent mixture 



93 



Glycerol 



Undiluted 



10C 



10 per cent mixture 



100 





do 



94 



Nicotine (40 per cent, as sulphate) 



Do 



1-32 



80-90 



1-64 



80-95 





10 per cent mixture 



100 



Sabadilla seeds 



Dust 



100 



Turpentine, crude wood 



Undiluted 



100 



Dust 



100 









These data show little of interest, except the efficiency of sabadilla 

 seeds (Sabadilla officinalis Brandt). These seeds or extracts are 

 largely used in remedies for vermin on the human body, especially 

 in the hair, but their use against bedbugs is rather unusual. In five 

 tests they proved to be very effective, killing from 95 to 100 per cent 

 in 48 hours. 



Mercuric chlorid, used as a dust, killed all of the treated insects, 

 but this material is too poisonous for general use in houses. 



The following is a list of various materials which were found to be 

 ineffective against bedbugs. The method of testing is indicated in 

 parentheses. 



Materials found ineffective against bedbugs. 



Allspice (jar). 



Alum (jar). 



Angelica root (jar and room). 



Arsenious acid (jar). 



Borax (jar). 



Boracic acid (jar). 



Chamomile flowers (jar). 



Colocynth pulp (jar). 



Eucalyptus leaves (jar and room). 



Formaldehyde (room, 8.87 per cent so- 

 lution, sprayed twice, 1 part to 14 

 parts water). 



Lead acetate (jar). 



Paris green (jar). 



Pepper, red (jar). 



Quassia chips (jar and room). 



Sodium bicarbonate (jar). 



Sodium fluorid (jar and room). 



