12 BULLETIN 808, U. S. DEPARTMENT OF AGRICULTURE. 
posed to be the only species present, and even tritici was considered 
a varietal form of it. Harris (T) described this species in 1830. 
Along in the twenties it caused such serious injury to barley in 
Massachusetts that the growing of this crop was abandoned in some 
sections. For years it was a scourge to barley-growing sections in 
the East. The Eastern States have largely ceased growing barley 
for a number of years now, and consequently have suffered very little 
injury. The barley-growing section has moved west, Wisconsin, 
Minnesota, and the Dakotas now being the most important barley 
States. Fortunately hordei does not seem to have been introduced 
artificially into those sections, which is the only plausible way it 
could be transferred from the main barley section in the East. Bar- 
ley, unlike wheat, is not grown generally in the intervening States, 
so that there is no chance for hordei to spread gradually westward as 
tritici seems to have done. 
During the late summers of 1913 and 1911 the writer visited por- 
tions of Xew York State that were formerly great barley-growing 
centers. Only a very few infested barley stubbles were found after 
extended search in 1913, and none were found in 1911. Very little 
barley is grown there now. The fields, as a rule, are widely sepa- 
rated and the stubble usually is plowed under before hordei has had 
an opportunity to emerge, consequently it has been almost extermi- 
nated. This is one of the very rare instances of a once serious pest 
becoming practically extinct. Its scarcity is such that the writer had 
never seen a specimen of hordei until the spring of 1911, except the 
few fragmentary specimens in museums. 
H. hordei has been confused with tritici and secdlis undoubtedly, 
and probably with vaginicola and others. As the coloration of the 
legs of hordei varies to a considerable degree it is not surprising that 
confusion arose years ago, since that was one of the main characters 
used in identifying the species. 
MANNER OF INJURY. 
Barley plants are affected by hordei (PL IV, A) in exactly the 
same manner as wheat plants are by tritici. In fact, but for the 
slightly different appearance of barley straw from wheat straw, the 
galls could not be separated once they became mixed. TVlien barley 
plants are badly infested galls may be found above every joint. 
HOST PLANTS. 
The writei has now oeen breeding hordei in confinement for 1 
years and has never succeeded in inducing it to breed in any plant 
other than barley. 
