off the bark ; the cover is then put on the nest by using 

 spinneret ; the whole completed in twenty-four hours 

 (a, Fig. i). If in a crevice of the bark, the nest is made 

 in different shapes. It is noticeable in the Winter nest 

 the tops and sides are washed with fluid from spinneret, 

 making the nest water-proof to a great extent. 



The moth remains in the pupa or chrysalis form from 

 nine to twelve days, in our usual May weather. At the 

 proper time the pupa case is burst open, and the perfect 

 moth appears (/, Fig. i). 



It may be asked, How does the moth get out of the 

 nest so neatly made, etc. ? By some freak of nature, 

 about twenty-four hours before transformation, the pupa 

 is forced through one end of the nest (i, Fig. i), so that 

 the perfect insect can easily escape. 



The chrysalids of this moth are capable of moving 

 lively at any time, from the time they assume the chrys- 

 alis or pupa form until the insect escapes perfect. 



PROBABLE RATE OF INCREASE OF THESE MOTHS. 



Entomologists claim that of the lepidopterous insects, 

 including butterflies and moths, nearly one thousand kinds 

 are known in the United States. That each female lays 

 from 200 to 500 eggs. Taking 200 as the lowest num- 

 ber, twelve female moths in one orchard would produce 

 2,460 caterpillars ; if one half these were females, they 

 would produce 240,000. In proportion, the third gen- 

 eration would reach 24,000,000. 



From the observations stated, we are led to believe 

 that the destruction of this pest must be consummated 

 while it is in the caterpillar state. 



Is this pest of the orchard only found in California? 

 The damage done by this pest in the States east of the 

 Rocky Mountains is too well known to need repeating. 

 At the present time it is doing so much damage to the 

 fruit crop in parts of Australia that a Commission has 



