68 



THE REPORT OF THE ' 



No. 36 



The Pupa 



The pupa is about one-half inch long, is yellowish-brown in colour and 

 has the shrivelled larval skin attached to the posterior end. It is found in the 

 soil in a little earthen cell, at a depth of three to seven inches. 



Duration of Pupal Stage. An attempt was made to determine definitely 

 the duration of this stage. Larvae and pupse were reared in pill boxes, but all 

 succumbed before reaching the adult stage. Our observations in the field 

 indicate that the insects are in the pupal stage about three weeks. 



Breeding Grounds 



During the latter part of May, a survey was made of sections of the infested 

 area at Fenwick, in order to locate the principal breeding grounds. As a rule, 

 in doing this work, the owner of the farm which was being surveyed was requested 

 to accompany us, and in this way we were able to show the growers where the 

 insects were breeding. 



Rose chafer larva 

 or grub x 2. 



Rose chafer pupa 

 (natural size). 



Some of the data secured from this survey are as follows: 



Neglected raspberry patches : Six plots (1 square yard) were examined and 

 from 68 to 177 larvae and pupae per square yard were found, the average being 

 115. 



Uncultivated graperies: Seven plots were examined and from 16 to 135 

 insects per square yard were found, the average being 84. 



Land in grass during 1821-22: Nine plots were examined, and from 18 

 to 105 insects per square yard were found, the average being 45. 



Land in oats or wheat during 1921: Six plots were examined and from 20 

 to 51 insects per square yard were found, the average being 30. 



Well-kept lawns proved to be practically free. 



Rather to our surprise only an insignificant number of insects were found 

 in roadsides at Fenwick. However, this fall at Oakville, roadside plots yielded 

 from 40 to 184 larvae per square yard, with an average of 84. 



In land which had been planted to corn, potatoes or grapes, and which had 

 been well cultivated during the season of 1921, no pupae or larvae were found. 



No insects were located in clay, clay loam or in gravelly soils. 



The breeding places were largely confined to areas near graperies. 



Surveys of sections of the Fenwick and Oakville infested areas made this 

 fall, furnished us with additional evidence that neglected sandy fields are the 

 all-important breeding places, and that the rose chafer does not breed at all in 

 heavy soils. It is of interest to note here that in a common at Fenwick, 549 

 iarvae were counted in one square yard. 



