CHAPTER VI 

 PEAR AND QUINCE INSECTS 



The most injurious insects attacking the pear are the codlin- 

 moth (p. 10), San Jose scale (p. 162), the pear psylla and 

 in some regions the pear thrips. While more distinctly an 

 apple tree pest, the codlin-moth annually causes a loss of 

 nearly a million dollars to the pear crop. 



Owing to the fact that the calyx lobes of the pear remain 

 open and do not close up as in the apple, spraying for the codlin- 

 moth is less effective on pears than on apple. Insects often 

 cause serious injury to pears indirectly by distributing the spores 

 of the bacterium, causing the disease known as fire-blight. 

 Their legs and mouth parts become smeared with the sticky 

 liquid containing the spores, which are thus introduced into the 

 tissues of the plant by the claws in walking over the tender tips 

 or by the beak when feeding. 



The Pear Slug 

 Eriocamqmides lirnacina Retzius 



For nearly two centuries this insect has been recognized as 

 an enemy of the pear and cherry in Europe, while in this 

 country its history goes back to the extensive account published 

 in 1799 by William D. Peck of Massachusetts. It was probably 

 introduced into New England in colonial times and is now 

 generally distributed wherever its food-plants are grown. While 

 in Europe it has been reported as feeding on a large number of 



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