160 SIXTEENTH BIENNIAL REPORT 



Control Measures 



In spite of a great amount of careful and conscientious investigation, particu- 

 larly in Canacla and in Oregon, no really practical and satisfactory remedial 

 measures have been developed. 



Barrier Method — Taking into account the inability of the beetles to fly, we 

 conceived the idea of a barrier about the newly set fields to keep tliem out. The 

 barrier used eonsisted of 12-inch boards placed on edge about the field, well 

 braced from the inside, all the joints carefully fitted and made insect proof. A 

 Strip of tin was tacked along the top edge of the fence projecting out over the 

 edge of the board about one and one-half inches. 



The barrier proved reasonably effective in excluding the weevils, and though 

 the cost of construction is considerable. the idea is not impracticable. The plan 

 has never proved populär with the growers, and none, so far as we are aware, 

 have adopted this System. 



One Crop Rotation — The most successful plan and the one recommended by 

 Canadian workers and ourselves as apparently the only one at present feasible, 

 is the growing of the plants only one full-crop year and then destroying the field 

 immediately after the harvesting of the main berry crop. 



In our common practice of planting in the spring and cultivating the first 

 season ; take one crop of berries the second spring and plow up the fields just 

 as soon a.s the berries are off. The soll should be worked up well or stirred fre- 

 quently, and strawberries should not be planted ou the ground for two seasons. 



Spraying with arsenicals has been tried. The beetles feed but sparingly and 

 apparently avoid sprayed foliage. No success has followed this treatment. 



New Plants should by all means be obtained from uninfested sections. Where 

 obtained from a suspicious district, the plants and Containers should be handled 

 with caution and examined carefully for weevils. Previous to planting, dip the 

 plants in a tobacco Solution consisting of Black Leaf 40, four tablespoonsful ; 

 soap, one-fourth pound ; dissolved in five gallons of water. 



AUied Species of Weevil Found on Strawberry 



Two allied species of weevils have been found infesting strawberries in Ore- 

 gon. The larger weevil (Otiorhynchus sulcatus) (See Plate — , Fig. 9.) occurs 

 about everywhere that O. ovatus does. It apparently does not spread rapidly nor 

 multiply fast enough to injure the field to a noticeable extent. It is apparently a 

 more serious pest of greenhouses, being particularly serious on cyclamen, begonias 

 and similar potted plants. 



Otiorhynchus rugifrons (See Plate — , Fig. 8) is apparently very limited in its 

 ränge. The only serious infestation at present known is in the Oswego section 

 south of Portland. The weevils have been observed in the Gresham section, but 

 no heavy damage directly traceable to them is known in this neighborhood. In 

 the Oswego section there are many of the growers who have given up straw- 

 berry culture entirely. and others report most diseouraging prospects where this 

 pest is present. In a great many cases the fields were so severely injured the sec- 

 ond season that a füll crop was not realized. This beetle is slightly larger than 

 ovatus, more prolific and may prove a worse strawberry pest than its dreaded 

 ally. No especial study of these species has so far been made in Oregon. It would 

 seem that the same remedial measures would apply as for ovatus. 



STRAWBERRY CROWN MINER 



( Aristotellia abscondetella) 

 This strawberry crown miner is present in the State of Oregon about every- 

 where that the strawberry is grown. In many localities fields have been observed 

 which were severely injured, and an examination showed this pest to be wholly 

 responsible for this trouble. 



