New York Agkicultural Expp:rimi;xt Station. 357 



the most conspicuous injuries to blossom and leaf clusters during 

 the past season were observed with such varieties as Astrachan, 

 Gravenstein, Mcintosh, Ben Davis and Oldenburg. Proximity 

 to pear and sweet-cherry plantings rather than varietal suscepti- 

 bility may be the true explanation for the differences in the extent 

 of injury among these fruits. 



Sweet cherries, including such varieties as Black Tartarian, 

 Napoleon Bigarreau, Schmidt Bigarreau and Windsor, the leading 

 commercial sorts, were frequented by large numbers of the thrips 

 from the time of the spreading of the winter bud scales to the 

 dropping of the blossoms. Bearing in mind the destructiveness 

 of the thrips to this fruit in California, careful observations were 

 made to ascertain the effects of the pest upon sweet cherries. 

 While the conditions were apparently favorable for its activities 

 it caused very little harm. In spite of the abundance of the in- 

 sect the trees produced good yields and the fruit v/as of superior 

 quality. The most noticeable work of the insect showed on the 

 stems of the cherries, which were scarred and rough in outline as 

 a result of the incisions made by the adult females in depositing 

 their eggs; and on the leaves, which were spotted with pale areas 

 and were full of holes through the feeding of the larvae and adults 

 on the undersurfaces. The effects of oviposition upon the stems 

 of cherries will be studied closely in the future as nearly all grow- 

 ers state that the 3'^ellowing of cherry stems is of quite common 

 occurrence and is frequently attended by early dropping of much 

 of the fruit. Tbis has been attributed to imperfect fertilization, 

 but it is possible that under some conditions the deposition of eggs 

 by the adults weakens the cherry stems and induces premature 

 dropping. Larvse were observed in large numbers under the husks 

 or loose calyces of the fruits and although they caused abrasions 

 in the surfaces of the cherries such injuries were of no material 

 importance. 



Sour cherries such as Montmorency and IMorcllo showed similar 

 injuries but to a less extent than upon the sweet sorts. Plums 

 were generally infested with the thrips and its work upon fruit 



