'254 STATE HORTICULTURAL SOCIETY. 



pected attacks of this pest. These facts must convince the pear-growers, 

 of New York state especially, where the insect seems to have obtained the 

 strongest foothold, that they have to fear a very serious pest. Although 

 very insignificant individually, this enemy becomes formidable and very 

 destructive when the conditions are favorable for its reproduction in 

 countless numbers. 



THE PAST HISTORY OF THIS PEST. 



The pest is an old offender; and its recorded history in this country 

 shows that it has been present for many years in or near most of the local- 

 ities above noticed. The insect was probably first introduced into this 

 country upon young pear trees imported from Europe in 1832 by Dr. Ovid 

 Plumb of Salisbury, Conn, Dr. Plumb first noticed the insect in 1883; 

 and durins: the next five vears he lost several hundred trees from its rav- 

 ages. By 1848, when the pest was first brought to the notice of an ento- 

 mologist, Dr. Harris, it had spread into Massachusetts and into Dutchess 

 and Columbia counties in New York. In 1879, W. S. Barnard observed 

 the pest in destructive numbers at Ithaca and at Saratoga, N. Y. 



The earliest record we have of its appearance further west is in 1871 

 when Dr. LeBakon recorded a severe attack upon young pear trees in 

 Illinois. Mr. E. A. Schwarz has found the insect in Michigan. Prof. 

 J. B. Smith of New Jersey has been unable to find it in that state, and 

 we have no record of its occurrence further south. 



It is thus seen that the pest is quite widely distributed over the north- 

 eastern portion of the United States and has reached the Mississippi valley 

 in its westward progress. The severe outbreak of 1891 indicates that the 

 insect has been increasing in numbers. It has apparently reached a point 

 in New York state, at least, where it only awaits favorable opportunities, 

 in meteorological conditions possibly, to repeat its ravages of last year in 

 unexpected localities. Pear- growers should be watchful and prepared to 

 fight it early in the season, 



its classification. 



This pear pest is one of the true bugs belonging to the sub-order 

 Homoptera, family Psyllidae, commonly known as jumping plant-lice 

 from the leaping habit of the adult. Their general name, Psylla, is the 

 Greek word meaning a fiea. The Psyllid fauna of Europe comprises more 

 than one hundred and fifty described species and has been thoroughly 

 studied. Dr. Franz Low of Vienna added much to our knowledge of the 

 classification of this group and he has described the life history and habits 

 of several species. Dr. E. Witlaczil of Vienna has written exhaustively 

 on the anatomy of the family. 



In the United States but little attention has been paid to the Psyllidae, 

 and less than twenty species have thus far been recognized. 



Three species of Psylla infest the pear tree in Europe — pyrisuga, 

 pyricola, and pyri; pyrisuga does the most damage, and p7/?*i is com- 

 paratively rare. We have, as yet, no native species of Psylla feeding on 

 the pear tree. Our pest, Psylla pyricola, although it was observed in 

 this country in 1833, received its name in Europe fifteen years later, or 

 aboiit the time Dr. Harris' attention was called to it here. Previous to 

 1848, European writers had referred to the species as Psylla pyri, not 



