February,'22J wells, bishopp & laake: derris 95 



In order to determine the results of the use of derris on dogs which 

 were not removed from their flea-infested quarters, treatment was 

 begun on three heavily infested animals. Dust was applied on all parts 

 of the animal at the rate of one-half to two and one-half grams. In 

 the case of one of these dogs all fleas disappeared after the second 

 application and none were found subsequently. Probably the cool 

 weather of December held the breeding in check, however. In the 

 other tests live fleas were found about a week after each treatment and 

 the number gradually increased until the next application was made. 

 Three treatments, however, reduced them to comparatively few and the 

 tests were discontinued. 



Several cats were treated with about three pinches of derris each. 

 No injury whatever was observed to the hosts and the fleas were all 

 destroyed, although where the cats had freedom some living fleas were 

 picked up a few days after the application and apparently remained on 

 the host. 



In one test puppies rather heavily infested with the sticktight flea 

 {Ecliidnophaga galUnacea) as well as the dog and cat fleas, were each 

 treated with one gram of undiluted derris. In a few hours dead dog 

 and cat fleas began dropping off the hosts and the following day all 

 specimens were dead, though many sticktights remained attached. 



Summary and Conclusions 



Derris powder is satisfactory as a destroyer of Mallophaga on chickens 

 and cattle, but apparently not quite as effective on the latter as sodium 

 fluoride. 



It is very effective against Anoplura on cattle and dogs, one treatment 

 accomplishing the destruction of all stages. 



The results of its use against fleas on dogs and cats are probably 

 most striking, very small amounts being sufflcient to destroy all fleas 

 present. 



It appears to be effective for lice and fleas when reduced with from 

 one to ten parts of a carrier to one part of derris. 



Mr. H. a. Gossard: Where can we obtain derris commercially? 



Mr. F. C. Bishopp: There is no commercial supply now available 

 in this country, but I believe, with a demand for the product, that it. 

 will be put on the market. I understand that an English chemical 

 company is now producing it in the East Indies, and furnishing it as 

 an insecticide in South Africa. It is said that they are in position to 

 supply a considerable quantity of it. I don't know that the supply 



