30 



Thi.s table is not complete, in that not sufficient observations were 

 made at lower and higher temperatures; and it is dangerous to make 

 any extended conclusions therefrom. A study of the table shows: 



First. Under a low temperature the length of this stage is longer 

 than at high temperatures. 



Second, The total temperature varies from 200'-' to 428"^ F., and the 

 average is 802-; and in general eggs have to be subjected to this 

 amount of heat before the}" hatch, whether it be for a longer or a shorter 

 period of time. 



Third. The eggs are not at the same state of maturity at the time of 

 oviposition, as at 24'-' we have from 9 to 18 days as the length of stage. 



Fourth. Under normal field conditions a small difference in temper- 

 ature causes but little change in the length of the stage. 



MORTALITY AMONG THE EGGS. 



Various ol)servers, among theui Washburn, Goethe, Card, Slinger- 

 land, and Cordley, have found that many eggs of this insect did not 

 hatch. There is little doubt- that at least one of these writers mistook 

 eggs from which the larv;e had hatched for dead eggs. The writer 

 has noted that many eggs l:>ecame hard and drj", while in others the 

 contents changed to a dark brown color. These changes may have 

 been caused by infertility, parasites, or the excessively hot sun. The 

 mortality as shown by our breeding-cage records is by no means so 

 great as the writer had supposed. The eggs, however, were more or 

 less protected. 



THE LARVAL STAGE. 



Considering the codling moth in its economic relations, it may be said 

 that the larval is the most important stage of the insect. Not only is 

 it distributed, and does all of its damage in this stage, but it is more 

 amenable to remedial measures. 



At the time of hatching the young larva is from one-twentieth to 

 one-sixteenth of an inch in length, of a semi-transparent whitish or 

 yellowish color, with large, shin}^, black head, and dark cervical and 

 anal shields. The body shows regularly arranged spots with short 

 hairs or seta3. 



If hatched upon the apple the young larva seeks a place to enter, 

 which is in general some irregularity upon the apple or at the calyx. 

 Slingerland, Card, and Cordley have made many excellent observa- 

 tions upon the place of entrance. When hatched upon the lea^'es they 

 may not find an apple for some time, and subsist by eating small por- 

 tions of the leaves. In confinement this often occurs, but it has never 

 been determined accurately how often it takes place in the field. The 

 writer has time and again noted these spots on the leaves in the field, 

 and has noted also that larvae hatched on leaves would have to go from 



