20 
BULLETIN 1182, U. S. DEPARTMENT OF AGRICULTURE. 
States. Furthermore, the species of pines represented above are 
from sufficiently different sections of the country to make available 
a possible host in most of our pine-growing regions and in such a 
variety of climates that some of them must be favorable for the insect's 
development. 
DISTRIBUTION IN THE UNITED STATES. 
Diprion simile is 
known to occur in 
nurseries in Connecti- 
cut, New York, Penn- 
sylvania, and New 
Jersey. Specimens 
have been received 
from Massachusetts, 
and the species is re- 
corded from Indi- 
ana. 11 
The history of the 
sawfly in the United 
States suggests that 
it was introduced 
with imported nur- 
sery stock, a view 
which is supported 
by the fact that in 
Connecticut, New 
Jersey, and Massa- 
chusetts it has been intercepted at quarantine inspection ports. 
The following list gives the localities from which the species is 
recorded (see also Fig. 8) : 
Connecticut: Derby, Greenwich, Hartford, New Canaan, and New Haven. 11 
Indiana. 
Massachusetts. 
New Jersey: Elizabeth, Rutherford, and South Orange. 12 
New York: Flushing, L. I. 
Pennsylvania: Chestnut Hill 13 and Penbrook. 13 
ECONOMIC IMPORTANCE. 
The imported pine sawfly is to be regarded as an extremely danger- 
ous visitor in the United States, because in Europe, where it is asso- 
ciated with Diprion pini L., the two are responsible for an immense 
amount of damage. D. pini has usually been considered the chief 
cause of this injury, but the two species are so closely allied 14 and so 
frequently confused that the presence of D. simile in this country 
must be regarded with apprehension. In Europe D. pini 15 is accred- 
ited with serious damage to pine in southwestern Russia, in 1914 de- 
foliating many acres of pine in the districts of Achtyr and Izium; in 
Germany, in Prussia, and particularly in Brandenburg and Silesia, in 
Fig. \— Diprion simile: Distribution in the United States. Around 
bUck soot i'llicites a reoort from a definite locality: a square 
spot inlicatss occurrence in the State, but without definite locality. 
" Britton, W. E., and Zappe, M. P. Op. cit., p. 275. 
" From a letter from Harry B. Weiss, dated Aug. 12, 1916. 
13 Localities for specimens determined by S. A. Rohwer. 
i« Diprion simile Hartig has been considered a synonym of D. pini L. 
" Britton, W. E., and Zappe, M. P. Op. cit., p. 276. 
