370 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1919. 
large staff of entomologists in economic work throughout the United 
States, concentrates here the work of identifying the vast number 
of insects that are sent in. Such sendings come in large part from 
its own agents, but almost as many come from officials of the State 
experiment stations, and no small number originate with the general 
public. The staff of trained specialists which does this indispensa- 
ble work is furnished by the Bureau of Entomology, which also turns 
over to the Museum each year some thousands of insects that have 
been reared or collected by its agents in the course of their investi- 
gations... The Museum, on its part, provides an associate curator 
and two preparators, and working quarters for the staff, as well 
as furniture and fixtures, insect cabinets, and entomological sup- 
plies generally. The older specialists are designated by the Museum 
as honorary custodians of the various groups (several have been do- 
ing this work for periods of time extending from 15 to 40 years) ; 
they give such portions of their time as are not required in identifi- 
cation work to the general improvement and classification of the 
collection. 
This system has resulted in the accumulation of a large and well- 
classified collection of the insects of the United States. Something 
has been done in getting together the insects of other countries also; 
but considering the enormous number of kinds of insects existing in 
the world, the foreign collection is still comparatively very small, 
and its increase is considered one of the foremost needs of the 
division. 
The economic importance of having a large and well-classified 
collection of foreign insects might not be evident at first glance, but 
can be easily demonstrated. 
Almost all the first-class insect pests that we have are foreign in 
their origin. Many have been traced back to very nearly the exact 
time and place of their entrance within our borders. A few of these 
may be cited to emphasize the point. 
The gipsy moth, which has done great damage in New England, 
and is a source of some hundreds of thousands of dollars of expense 
every year, was introduced from Europe in 1869. The brown-tail 
moth, in the same region of the United States and only a little less 
injurious and expensive, came from Europe in 1893. The pink boll- 
worm of cotton, for the eradication of which an elaborate campaign 
has been carried on for several years, was introduced from Egypt 
by way of Mexico, reaching the edge of the United States in 1915. 
The European pine sawfly (pl. 10) came into New England about 
1914. The Japanese peach moth? came from Japan about 10 years 
ago. The European corn borer, which is making its way westward 
1The Museum also receives material additions every year from the Bureau of the 
Biological Survey. 
