164 



son when the insects are seen to be sufficiently numerous to 

 warrant such treatment. This supplemental spraying, how- 

 ever, is not nearly so effective as the delayed dormant treat- 

 ment advised above. It is also possible to destroy man of the 

 flies in late fall or during warm spells in winter, though gen- 

 erally speaking we believe this to be more costly and as a 

 rule less effective than the spraying recommended above. 



Pear psylla infestation is indicated by sticky drops of 

 honey-dew first on the twigs and then on the leaves, the 

 amount increasing with the advance of the season and fre- 

 quently becoming so great as to smear most of the foliage 

 and drop to the ground. A sooty fungus grows in this 

 honey-dew and produces a characteristic blackening, espe- 

 cially toward the latter part of the season. There is no de- 

 struction of the buds or spoon-shaped deformation of the 

 leaves characteristic of thrip injury. 



The pear thrip is an extremely destructive and exceed- 

 ingly insidious enemy of the pear grower. It has been re- 

 sponsible for the almost total loss of the crop on certain va- 

 rieties of seckel and to a less extent on bartletts in large or- 

 chards in the Hudson Valley. It produces what has been 

 known as "Blossom blight" and in severely infested orchards 

 the leaf as well as the blossom buds may be blasted before 

 the developing tissues have pushed out to any great extent. 

 The thrip itself is a slender black insect only about 1-20 of 

 an inch long. It appears before or just as the fruit blossoms 

 begin to crack and its small size enables it to enter the buds 

 and quickly get beyond the reach of sprays. Six to ten of 

 these insects in a bud means the blasting of the blossom. 

 The presence of this insect is indicated first by drops of 

 sticky matter upon opening buds followed by shriveled re- 

 mains of flowers and leaves and this latter may be so marked 

 as to result in practically no foliage on the upper portions 

 of trees until into June. The treatment is early and thor- 

 ough spraying with a contact insecticide — nicotine and soap 

 being one of the best — before the buds open, just after the 

 blossom buds have pulled apart and after the young thrip ap- 



