ISTkw York Agricultural Experimext Station. 355 



even assert that the plantings exceed those of all other varieties 

 combined. 



Because of the increasing destructiveness of the thrips during 

 recent years, the opinion quite generally prevails that the intro- 

 duction of the pest in this community is of recent origin. How- 

 ever, there are no data on which to base any statement, and the 

 circumstances of its introduction and early history are conjectural. 

 The thrips has undoubtedly been longer established than has been 

 indicated, and the outbreaks during the past few years, cuhninat- 

 ing in the destructive attacks of 1910, were probably induced by 

 predisposing conditions arising chiefly from severe and prolonged 

 droughts for successive summers and the abnormally early devel- 

 opment of fruit buds during that year.^ 



OUTBKEAK OF THE THKIPS DTJEING 1911. 



The thrips was first observed on April 25 when a few specimens 

 were captured on pear trees. On April 28 the insects were gener- 

 ally more abundant and they were seen in varying numbers on 

 apricots, apples, sour and sweet cherries, pears and plums. Espe- 

 cially noticeable was the relatively greater abundance of the thrips 

 on Kieffer pears, and it appeared that the advanced growth of the 

 buds in orchards on warm and protected slopes made the trees 

 of this variety more attractive than other fruits in somewhat dif- 

 ferent situations. During the next few days the thrips swarmed 

 about the Kieffer buds which, while still compact, were now pro- 

 jecting beyond the bud scales. From the trees there exuded a 

 clear or brownish liquid while blossom clusters as yet not expanded 



1 The spring of 1910 was early and sudden. No records are available 

 showing the dates of blooming of pears at Germantown, but the season is 

 generally regarded to be from ten to fourteen days in advance of conditions 

 at Geneva, The dates for blooming of Seckel (a variety much subject to 

 injury by the thrips) at Geneva from 1904 to 1911 is as follows: 



1904 Mav 14 to May 17. 



1905 No' bloom. 



1906 May 4 to May 18. 



1907 May 16 to May 22. 



1908 May 17 to May 21, 



1909 Mav 14 to Mav 17. 



1910 April 25 to May 2. 



1911 May 10 to May 13. 



