242 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
paid for whether the borrowing takes the form of credit extended by a 
dealer for the purchase of goods or whether the money is actually rented 
by the borrower. Very often, cheaper insecticides can he obtained by the 
grower by a rearrangement of his methods of payment. 
The general credit standing of a prospective or actual purchaser is 
also a factor. A prospective purchaser who is known to pay his bills 
when due, ordinarily has an advantage over the purchaser whose credit 
standing is not satisfactory and he can, at times, obtain lower quotations. 
This discussion does not necessarily imply that each purchaser can 
receive the benefits of all these items as regards his own individual 
purchases, but it indicates the economic lines along which cheaper 
insecticides ma}^ be obtained. 
While these factors refer more evidently to competitive materials, the 
principles apply, in general, even in the case of non-competitive products. 
One of the economic functions of a proprietary substance is to remove it , 
as far as possible, from competitive price behavior. A brand name 
for a compound often sells it at a higher price than the chemically 
identical compound purchased as a chemical substance. 
Because of lack of sufficient information, the chemical designation of 
an insecticide cannot always be adopted; but serious consideration, 
with especially full collaboration of the chemist, should be given to the 
problem before decisions are made. Consideration should include not 
only the usual biological and chemical limits of error but also manufac¬ 
turing variations, which may be greater within the one brand at one 
time than as between different brands at other times. The history of 
the development of arsenate of lead exemplifies this principle. 
We grant we have ascertained the prices of a certain insecticide and 
we have discovered a substitute that is composed of ingredients which 
when properly combined and properly used will have the same or better 
effect at apparently a smaller expenditure of money on the part of the 
grower, or perhaps leave a greater profit in its adoption even though 
the apparent price be greater than the known material or the efficiency 
be less. This latter item is very important. The fact that one com¬ 
pound yields 95% control and another only 85% control does not of 
itself justify confining recommendations exclusively to the former 
substance. That same factor of convenience enters here, together with 
the other evident economic factors such as cost and efficiency of labor 
and its supply, the availability of the material and perhaps the limit of 
choice between 85% control and none. This status is met with in a 
number of instances where dusting is not as effective as spraying in 
