REPORT OF THE ENTOMOLOGIST. 209 
to California either direct from Australia or from South Africa, and will 
doubtless become quite a scourge; because most introduced insects are 
brought over without the natural enemies which keep them in check in 
their native country, and, consequently, multiply at a prodigious rate. 
It will be naturally partial to Australian trees, and shows a preference 
for Acacia, Eucalyptus, Orange, Rose, Privet, and Spirea. 
Much of the more valuable work in the Entomological Division must 
necessarily be done in the field, and I have twice been to Long Island 
with a view of studying a new enemy of junipers, a large number of 
valuable trees of this kind, belonging to Mr. P. H. Foster, of Babylon, 
having seriously suffered and many of them died from its ravages. 
This insect proves to be a web-worm (Dapsilia rutilana, Hb.,) new to 
this country and evidently introduced from Europe, where it had long 
been known to attack junipers, but without doing serious harm. [have 
also twice visited Yates County, New York, where there has been a sin- 
gular local irruption of the common Walking-stick (Diapheromera femo- 
rata, Say.), the insect having of late years abounded to such an extent as 
to defoliate and in many places to kill outright the timber trees, especially 
the red oak. Mr. F. C. Snow, of Esperange Farm, Branchport, N. Y., 
has particularly suffered from this insect. The clover crop at this place 
and in several counties of Western New York has also been seriously 
affected by two other insects new to this country, namely, a midge (Cedi- 
-domyia) that is undescribed, and a little beetle (Hylesinus trifolit, Ml.) 
that works in the root, so thoroughly killing whole fields that the root- 
less plants would gather before the mower and prevent harvesting. 
This also has been long known to work in clover in Europe, and must be 
considered a tolerably recent importation. 
While a good deal has in this way been added to our knowledge of a 
number of insects that may be considered of secondary importance only, 
from the fact that they are local rather than national in character; and 
while some of them are treated of in the following pages, I have occu- 
pied myself more particularly with four classes of insects that seriously 
affect American productive industries for good or for evil. These are: 
1st. Insects affecting the cotton plant. 2d. Silkworms. 3d. Insects af- 
fecting the orange and which so seriously threaten orange culture in 
Florida. 4th. Insects affecting the cranberry. 
The more technical and descriptive matter, which it has been deemed 
necessary to incorporate, in order to give scientific accuracy, will be 
printed in smaller type in order that it may be readily skipped by the 
practical man who cares not for scientific details. The measurements 
when very small are given in millimeters, as the metric system is des- 
tined sooner or later to be generally adopted. One millimeter (1 mm.) 
equals about one twenty-fifth of an inch (more accurately .03937). The 
figures have been made by myself, with the assistance of Mr. G. Marx, 
and are usually enlarged, the natural sizes being indicated by hair-lines, 
or in some other way, at the side. In submitting this report I take 
pleasure in acknowledging the assistance in all my office work of Mr. 
L, G. Howard and of Mr. Th. Pergande. 
Respectfully submitted, March 1, 1879. 
CHARLES V. RILEY, 
Entomologist. 
Hon. Wm. G. Lm Duc, 
Commissioner of Agriculture. 
14 AGR 
