New York Agricultural Experiment Station. 345 



The quality of primes that mature may also be Impaired by the 

 feeding of the larvae on the skin of the fruit causing a diseased 

 condition known as " scab." The Napoleon Bigarreau and Black 

 Tartarian cherries and Imperial prune are among the varieties 

 known to New York fruitgrowers, that are attacked by the thrips. 

 Almonds, apricots and peaches, while also subject to injuries, do 

 not usually sustain such serious losses unless the thrips are very 

 numerous. 



description, life history and seasonal notes. 



Adult. — The adult, which is the most destructive stage of the 

 species, is a dark-browoiish, four-winged insect about one-twentieth 

 of an inch long. The wings are long and narrow and are deli- 

 cately fringed with long hairs ; when at rest they lie horizontally, 

 along the back and are then very inconspicuous, thus often deceiv- 

 ing one momentarily as to the nature and range of the activities 

 of the insect. On account of the structure of the wings these in- 

 sects used to be designated " fringe-wings " (See Fig. 1), but now 

 they are more often popularly called " thrips,'' which is a Latin 

 name derived from the Greek 'V'V' , meaning a wood louse. The 

 species attacking pears is kno-\vn as the " pear thrips " because it 

 was first discovered in pear blossoms to which it proved to be very 

 destructive, although it has since been shown that other fruits 

 suffer equally from its injurious work. The mouth parts of the 

 thrips are largely suctorial in function, and consist of a broad, 

 cone-like structure projecting from the underside of the head. 

 The apex of this organ is quite sharp and of a horny nature, 

 adapted to lacerating soft vegetable tissues. In feeding, the 

 thrips punctures and rasps tender flower and leaf structures, set- 

 ting free the plant juices, which are sucked up Into the alimentary 

 canal. This feeding may cause much damage to fruit trees. The 

 insects seek preferably the rudimentary flower and leaf parts In 

 the partially opened buds, but when the buds are more fully devel- 

 oped they feed more or less openly on the stamens, pistils, petals, 

 tender leaves and apparently on the secretions from the nectaries 



