PEAR GROWING IN CALIFORNIA. 371 



CHAPTER XIV. 



INSECT, MITE AND OTHER ANIMAL PESTS OF THE PEAR. 



Pear trees are attacked by such a variety of insect pests that 

 in order to be most successful in pear culture it is desirable that the 

 grower be able to recognize the various species and to know what treat- 

 ment is necessary for their control. The most cosmopolitan and impor- 

 tant of these pests have been treated somewhat at length, while those of 

 lesser importance have been mentioned very briefly. The fact, however, 

 must not be overlooked that certain insects that are of lesser importance 

 in one locality may be very serious somewhere else and even though such 

 pests as leaf roller and thrips have not been described in detail there 

 are certain parts of California where they are exceedingly serious. In 

 the case of codling moth it may be considered to be the most cosmopoli- 

 tan of all and in practically every pear-growing section of the state its 

 ravages are seen, and spraying for its control is absolutely necessary. 



CODLING MOTH (Carpocapsa pomonella). 



This serious insect pest of the pear and apple is more easily controlled 

 in orchards of the former fruit than in those of the latter, and while 

 spraying must not be neglected in pear orchards wherever this insect 

 occurs, the exacting precautions which are necessary in badly infested 

 apple orchards are not necessary when spraying the pear. 



Habits. 



The different stages of the pest are as easily recognized in pear as in 

 apple orchards, when equally abundant. The winter season is always 

 passed in the mature larval stage, under loose bark, in cracks of the 

 trees, in packing houses where fruit was packed during the season and 

 in various other places. The wintering larvae are protected by tough, 

 impervious cocoons of silk. As soon as the weather gets warm in the 

 spring they become somewhat active, and pupate within the cocoons, 

 from which emerge the mature moths of the first or spring brood. The 

 earliest of these moths appear in the orchards about the time when the 

 trees are in full bloom, but the majority do not emerge until later, or 

 when the fruit is approximately inch through at the widest part. 

 The difference in time of the emergence of moths may be due partly to 

 the length of time the larvae have been in hibernation, but more likely 

 to a difference in their location, some being in warm, sunny situations, 

 and others in cool, shady places which have a tendency to retard their 

 development. The mortality among hibernating larva? is often very 

 great, but varies with seasons. As the abundance of first brood larvae 

 in the fruit depends upon the number of hibernating larva? that survive 

 the winter season, the natural mortality is exceedingly important, and 

 has a direct bearing on the number of applications of a spray for the 

 control of the insect. 



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