106 INSECTS INFESTING THE APPLE TREE. 



seen, as at e Fig. 79. On reaching the tree it searches for a 

 nesting place under the loose bark, in the crotches, or in any 

 cavity it can find. If it comes in contact with a branch when 

 leaving the fruit, it generally crawls toward the crotches, or 

 until it reaches a hiding place. If the place selected is under 

 the loose bark, it commences building an oval-shaped wall 

 about one sixteenth of an inch high, composed of silk from 

 the spinneret, and sometimes mixed with pieces gnawed off 

 the bark. A silken cover is then put on the nest by using the 

 spinneret ; the whole completed in twentj'-four hours. If in 

 the crevice of the bark, the nest is made in different shapes. 

 It is noticeable in the Winter nest that the top, sides, and bot- 

 tom are washed with the fluid from the spinneret, making the 

 nesf water proof to a great extent. 



The moth remains in the pupa or chrysalis form about nine 

 days in our usual May and June weather ; a little longer if the 

 weather is cool. At the proper time the pupa case is burst 

 open, and the perfect moth appears. (Fig. 70, /and g.) 



PROBABLE RATE OF INCREASE OF THESE iMOTHS. 



Each female lays from tw^o hundred to two hundred and 

 fifty eggs. Taking two hundred as the lowest number, twelve 

 female moths in one orchard would produce two thousand 

 four hundred caterpillars. If one half of these were females, 

 they would produce two hundred and forty thousand. In 

 proportion the third generation would reach twenty-four mil- 

 lions, supposing that no untimely deaths took place. Most of 

 the books on this subject speak of the codlin moth as going 

 through l)Ut one generation in a year. This may be true in 

 colder climates and shorter seasons than ours, but in parts of 

 our favored State there is no question that two or three gene- 

 rations or broods are common. From personal observations 

 I know that the rule for the Sacramento Valley is three 

 broods each year. In 1881, on account of the early appear- 

 ance of the first ninths, as noted above, we had four broods. 

 These facts explain the exceptional importance of this insect 

 in California. 



I have in my possession a vial containing eighty-five eggs, 

 deposited l)y one codlin niotli. 1 have read statements by 



