64 THE REPORT OF THE No. 36 



is placed at the joints where the weevils might cross. It is almost impossible 

 for weevils to cross such a barrier. They have been seen to crawl through the 

 oil but they never survive. This type of barrier is at present the one most 

 generally used by growers in the Victoria district. It was first used at Gordon 

 Head by Mr. G. Vantreight who placed a barrier of this description between 

 two of his plots and thereby saved his young plantation from destruction by 

 the weevils crossing from the old plot. Later we used an improved form of this 

 barrier on our experimental plots. Access to the field is by means of a panel 

 which can be removed to allow a team to pass. 



The cost of these devices is an important matter, and hitherto there has 

 been a certain amount of objection to them on the score of expense. The costs 

 have now been greatly reduced, and one important fact must not be lost sight 

 of, that these costs are not an annual charge, because the barriers last for a number 

 of years. The barriers can now be erected for a sum of from $60 to $78 for one 

 acre including labour, the cost for several acres being proportionately less. The 

 annual upkeep in the case of a tanglefoot barrier would be $25 and for an oil 

 barrier $10 per acre. The minimum time that the barriers would be expected 

 to last is three years, and thus the total expense for three years would be approxi- 

 mately from $90 to $120 or from $30 to $40 per acre per year. But as a matter 

 of fact the barriers will last very much longer than this and there is no reason 

 to suppose that given ordinary care and protection against decay when first 

 erected that the lumber would not last for five or six years. We are still using 

 at Gordon Head lumber that has been in use for four years which only received 

 a coat of paint and it appears to be still in serviceable condition. 



It has been difficult, owing to the fact that growers have had two unpro- 

 fitable years in succession, to induce them to spend anything at all on weevil 

 control, and they do not realize that the expense is spread over a number of 

 years. The average value of a full crop of strawberries in this district is $800 

 per acre, so that the annual charges suggested above are not by any means high. 

 Growers who are using barriers are unanimously in favour of their use. As 

 one of them, who had at first been rather sceptical, remarked to me the other 

 day: "I can see now that this thing is going to pay for itself many times over." 



To sum the matter up, it appears as if the growing of strawberries between 

 barriers in a weevil infested territory was coming to be a recognized necessity. 

 Local growers are becoming strongly impressed with the idea, and recognize 

 that the immunity from weevil attack which the barriers provide will abundantly 

 justify the outlay. One of the principal advantages claimed for the barriers 

 is that a grower can now depend on obtaining more than two crops from one 

 planting and owing to freedom from weevil the fields may remain in strawberries 

 for four years or even longer. The presence of other pests than weevils, however, 

 may upset this comfortable belief, but at present there seems to be no doubt 

 that the adoption of these aids to weevil control will be of the greatest value 

 in obtaining larger returns for the strawberry grower. 



RECENT WORK ON THE ROSE CHAFER IN ONTARIO 



W. A. Ross and J. A. Hall, Dominion Entomological Laboratory, 



Vineland Station 



In certain sandy sections of Ontario, such as at Fenwick, Oakville and 

 Simcoe, the rose chafer has proved to be an extremely troublesome and destruc- 

 tive pest of grapes, other fruits, flowering plants, etc. At Fenwick the rose 



