REPORT OF THE SOCIETY I 31 



The insect about to hibernate builds itself a small oval silken cell about 

 4 or 5 mm. long, closely woven and usually completely hidden beneath a 

 scale or piece of bark, which often makes it difficult to find the hibernacula 

 without careful search. 



The stage at which the larva hibernates varies. The observations 

 recorded in Table II show that as many as four moults may take place 

 before the larva ceases feeding. Measurements made in May on the heads 

 of hibernating larvae showed that the majority hibernated after the third 

 moult. Some were in the fifth instar, some in the third and a very few in the 

 second. This difference in the stages of the hibernating larvae might be 

 expected if it is remembered that the emergence of the females and the laying 

 of eggs extend over a period of four or five weeks and that there will be a 

 corresponding difference in the ages of the larvae at the time of hibernation. 



This method of hibernation was first suspected by Fletcher in 1885 and 

 confirmed by him in Nova Scotia orchards in 1891. In 1893 Slingerland 

 published the results of his researches on the bud-moth which left no doubt 

 as to its method of hibernation. Previous to this time it was generally 

 believed that the larvae fell to the ground with the leaves in the autumn. 



Kollar (1840) stated that the insect in Austria hibernates in the egg 

 stage. Theobald finds that in England as a rule the half-grown larvae 

 hibernate, but he has found such small larvae in the spring that he believes 

 some individuals hibernate in the egg stage. Might not these small larvae 

 be some that have hatched late and wintered in the second or third instar as 

 I have found in Quebec? 



Emergence of Larvae in the Spring. — The time at which the larvae 

 begin to leave their hibernating nests in the spring depends on the earliness 

 Or lateness of the season. Tiius in 1914 the first larvae emerged on May 7th, 

 but in the following year when the season was about two weeks earlier they 

 were entering the buds on April 26th. The caterpillars do not all 

 leave their hibernacula at the same time but their emergence extends over a 

 fortnight. Thus, for example, in the seasons above referred to, hibernating 

 larvae were found as late as May 18th and May 7th respectively. 



The habits of the larvae in the spring have already been described in 

 discussing the injury done to their host plants. After emergence the 

 larva undergoes three to six moults according to whether it has hiber- 

 nated in the second, third, fourth or fifth instar. 



The oldest larvae are full grown at the beginning of June and the earliest 

 pupae are found during the first or second week in June. The small silken 

 cocoon in which the insect pupates is sometimes constructed within the 



