1923 ENTOMOLOGICAL SOCIETY. 61 



MECHANICAL DEVICES AS AIDS IN THE CONTROL OF THE STRAW- 

 BERRY ROOT WEEVIL (0. ovatus L.) 



W. Downes, Gordon Head, B.C. 



Experimental work on Stawberry Root Weevil control has been carried 

 on during the last four years at Gordon Head near Victoria, British Columbia, 

 and one of the principal features of this work has been the trial of various weevil- 

 proof barriers. It was realized early in the work that while the established 

 methods of keeping the weevil in check by the use of proper crop rotation, and 

 by ploughing up infested fields in the fall, were efficient enough so far as they 

 went, yet these methods did not prevent the weevils from passing from one 

 plantation to another and re-infesting newly-planted fields. Moreover, efficiency 

 in control by cultural methods only, is dependent very largely in a closely settled 

 district upon co-operation between neighbouring growers, and with the varying 

 opinions held by many as to the best cultural practices and weevil control 

 methods, such co-operation is nearly impossible to bring about. The desirability 



Crude oil barrier at Gordon Head, B. C. 



was apparent, therefore, of providing some barrier or device which would make 

 a grower independent of his neighbour's plans. Also, weevil control by cultural 

 methods entails the replanting of fields every third year, as even with the best 

 of care it is generally found that only two crops of berries can be depended upon. 



To meet this deficiency in our weevil control methods two types of weevil- 

 proof barrier have been tried at Gordon Head. Both of these barriers have given 

 excellent results, in that it has been found possible not only to keep plantations 

 nearly free from attack, but by their use to destroy the hordes of adult weevils 

 passing from one plot to another or from adjoining infested land, so that 

 the menace from their presence is removed and the risk of infestation annually 

 becomes less. 



The first kind of barrier tried was of the tanglefoot type, as first suggested 

 in 1912 by Prof. Lovett in Oregon. It is constructed of l"x 12" lumber, set on 

 edge about two or three inches in the soil and supported at the joints by 

 2" x 6" posts eighteen inches in length to which the boards are nailed or bolted. 

 Bolts are preferable to nails as warping is thereby largely overcome and the barrier 



