INSECT POWDER. 13 
to 25 per cent of the powdered flowers remain in the sieve. This refuse 
is not used in the best quality insect powder, but some manufacturers 
repowder it and mix it with the fine good powder. Mixed with the 
powdered leaves and stems of the Pyrethrum plant, it is used also as 
a smudge for mosquitoes and flies. 
EFFECT OF INSECT POWDER ON INSECTS. 1 
In the account of the discovery of the nature of insect powder by 
Sumttoff (5) no details are given as to its use. It is simply stated 
to be one of the most active means of protection against harmful 
insects, ' ' attracting them by its characteristic odor and then numbing 
and killing them, but to man and larger animals it is entirely harmless." 
Noodt (205), in 1858, wrote: 
The powder has the property of numbing all insects in a short time and subsequently 
killing them. Strewn in the room and in the bed it is a poison for lice, fleas, bugs, 
flies, moths, etc. * * * . 
In the collection of insects it has been used for a long time not only to quickly kill 
them but also to protect them against other insects, and it can be recommended not 
only for this use but also in herbariums and other natural history collections, since 
ants also quickly die from it. 
In 1858 Browne (38) recommended the trial of Persian insect 
powder, or a decoction of it, against the scale of orange trees (Coccus 
hesperidum) , but the test does not appear to have been made. This 
is the first use of insect powder against a definite insect suggested in 
the United States, and the first time it is spoken of for use on fruit 
trees. About the same time Willemot (294) records the results of ex- 
periments on the destruction of noxious insects in France with 
Pyrethrum. 
Glover (99), in 1864, described the first experiment recorded in 
this country on the insecticidal efficiency of Persian insect powder: 
This powder had a curious effect on some Croton roaches we were experimenting 
with; when sprinkled over them or placed in a circle and they made to pass over it, 
for a few steps they appeared very lively, but soon staggered, and after a few struggles 
fell over and soon ceased to live. 
Saunders (239), in 1879, was one of the first to describe the effect 
of insect powder upon house flies and green aphis. About the same 
time Carpenter (44) published the results of his experiments with 
Pyrethrum on different insects. As a result of these experiments, he 
states that "all insects having open mouth parts are particularly 
susceptible to this powerful drug." Howard (138), in 1882, described 
the effect of Pyrethrum upon the heartbeat of Plusia brassier (cab- 
bage worm). 
A great amount of work has been done since 1879 by the United 
States Department of Agriculture and the various agricultural ex- 
1 The statements given under this heading are merely quotations from the literature and are included 
for their historic interest. They are not to be taken as representing the present opinion of the Department 
of Agriculture concerning the efficacy of this product. 
