STRAWBERRY CROWN GIRDLER AND OTHER INSECTS. 211 



This method is in accordance with preventive means com- 

 monly accepted as the only practical way of combating other 

 tmderground enemies, such as the white grub and the wire worm. 



No extended tests have been made in Maine as to what crops 

 would be best adapted for this purpose. At Houlton, however, 

 favorable opportunities for an observation were offered. Potato 

 iields were at hand on newly broken ground adjoining meadows 

 freely infested with grubs of the crown girdler. In two of these 

 fields, the roots of potato vines variously situated were examined 

 and in no case were larvae of the crown girdler found. This, 

 of course, is no positive indication that potato vines are never 

 attacked by this insect, but the situation of the potato field was 

 exactly such as would have proven the worst possible condition 

 for a strawberry bed ; and the apparent freedom of the field from 

 the grubs certainly seems significant. 



In localities where the strawberry crown girdler is present to 

 .any marked extent, it would be unsafe to set strawberry plants 

 in newly broken land. Some less susceptible crop (the potato 

 would probably serve) should be used first, and the soil so 

 thoroughly cultivated that grass or other weeds cannot remain 

 as a bait for the beetles, or food for such larvae as chance to be 

 already in the ground. 



Repellents. As most of the complaints against this beetle in 

 Maine were concerned with its entrance to houses, a few tests 

 were made to see if camphor gum could be used successfully as 

 a repellent to be placed at ciacks about baseboards or windows. 

 Between 30 and 40 beetles were placed in a space 6 inches in 

 diameter surrounded by a circle of powdered camphor gum piled 

 about an inch high. The beetles seemed neither stunned nor 

 excited, but walked about in the space and climbed over the 

 camphor apparently indifferently for quarter of an hour when 

 the beetles were taken and buried under a mound of the camphor 

 gum and left for nearly two hours. Shortly after the camphor 

 was removed, the beetles, deliberately stalked off, to all appear- 

 ances as well as ever. The experiment was repeated with 

 flowers of sulphur with precisely the same results. 



At Maysville Center where the beetles in troublesome numbers 

 were entering a house under the baseboard, a liberal application 

 of fresh pyrethrum powder was recommended. The report 



