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HOW THE PSYLLA WAS INTRODUCED. 
The suddenness and severity of the appearance of the Psylla in 
Maryland makes the question of its introduction one of considerable 
interest. Upon inquiry it was developed that both Mr. Emory and 
Mr. Brown had procured pear trees from a nursery in New York 
State in 1890 or 1891, and it is unquestionably from this source that 
the Psylla was introduced. It will be remembered that this was just 
at the time when the Psylla put in an appearance in such extra- 
ordinary numbers in New York State, as reported by Mr. Slingerlaiul. 
Mr. Brown told me that he had heeled in a lot of young pear trees 
procured in the fall, near his house, for spring planting. These 
young trees were undoubtedly infested with hibernating Psylla s, 
and it was in the immediate vicinity of the point where these trees 
were heeled in that the outbreak occurred in this orchard. Mr. 
Emory about the same time procured a lot of young stock from the 
same nursery, and undoubtedly introduced the Psylla into his orchard 
with these trees, coming as they did from a New York nursery at a 
time when the Psylla outbreak was at its height in that State. In 
further confirmation of this, Mr. Emory is confident, he tells me, that 
the present year is not the first one in which the Psylla has been pres- 
ent in his orchard, and that he has observed indications for the last 
year or two which he has now no doubt were evidences of the presence 
of the insect. The multiplication of the insect in the orchard of Mr. 
Brown was very rapid at the start, and its entire disappearance after 
the first year is probably to be explained on the ground of some 
peculiar climatic conditions which obtained in his neighborhood, but 
did not extend northward to the orchard of Mr. Emory. Such condi 
tions are not unusual in the peach belt of Maryland, as illustrated by 
the fact that orchards separated by only a few miles and in the same 
conditions as regards soil and variety of fruit will seemingly be 
affected by cold waves or' storms, so that one will be barren while the 
other will be full of fruit. 
THE FUTURE OUTLOOK. 
When suddenly, confronted with an injury as unusual as this and 
as startling in its effects, one is naturally led to overestimate the 
immediate damage and to take a too despairing view of the proba- 
ble future. In the case of the pear-tree Psylla, however, I incline to 
the belief that while the seriousness of the present damage can not be 
questioned, the injury will be very much less in future, even if there is 
not an entire cessation of the trouble and a disappearance of the pest. 
The fact that this insect was imported into the United States with 
pear trees over sixty years ago, and was long since widely distributed 
throughout the pear districts of the northern States, and westward to 
the Mississippi, and has yet, during all this time, rarely been reported 
