; INSECT POWDER EE 
In grinding insect flowers 1t is not customary to add any material 
to assist the pulverization. Nor, with the exception of large stones, 
which may have been added to the bale, and certain bits of iron which 
are taken out by an electromagnet, is anything removed from the 
flowers as they are received. Such foreign matter as stems, either 
adhering or loose, sand, and dirt is allowed to remain. 
In Japan the process of manufacture is as follows (292): The 
flowers are dried in the shade for one day in the summer, after which 
some 8 pounds are placed in a stone mortar and powdered for about 10 
hours. ~This powder is then put through a sieve, and dried by steam 
heat at from 80° to 90° F. for 4 or 5 hours in a drying room. 
When well dried it is packed in tin containers. In the sieving 
process from 20 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: 
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 
ag dulling them, but te man and larger animals it is entirely harm- 
ess. 
Noodt (205), in 1858, wrote: 
The powder has the property of numbing all insects in a short time and subse- 
quently 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 recom- 
mended 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 Wuilemot (294) records the results of 
experiments on the destruction of noxious insects in France with 
ethrum. 
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 
§ 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, 
