210 MAINE AGRICULTUR.\L EXPERIMENT STATION. I905. 



test 40 beetles were kept without food for 7 days and then con- 

 fined for 36 hours with poisoned ehn leaves. At the end of this 

 time 32 beetles were dead and 8 alive. These tests, especially 

 the second, were arbitrary and unfair with respect to nomial 

 out-of-doors conditions because ordinarily the beetles would not 

 be so hungry and there would be unsprayed food within travel- 

 ing distance. The only significant fact concerned is if they eat 

 sprayed plants they die. In this connection the experience in 

 ^Montana '-■*' with new strawberry plants dipped in arsenate of 

 lead is exceedingly interesting. It was found in that instance 

 that the beetles avoided the sprayed leaves and began to feed 

 upon the roots of the strawberry. 



In view of the great range of food plants accepted by the adult 

 beetles there seems little help to be expected from the applica- 

 tion of poison except as it might serve to a certain extent as a 

 protection of valuable plants by causing the beetles to shun them. 

 Mr. R. A. Cooley * concluded that where adult beetles attacked 

 the leaves badly, spraying was better than no treatment and was 

 worth the cost and trouble incurred. The injury to strawberry 

 beds in ]\Iaine, however, has been (so far as known) by the 

 grubs alone, working at the roots, and thus spraying, here, would 

 be of no avail. 



Cultural means. The fact that grubs (larvse) of the crown 

 girdler were found during the past season at the roots of grasses, 

 white clover, and wild strawberry merely confirms the evidence 

 of other obser\-ers that the larva of this insect finds its natural 

 food in roots of grasses and other meadow plants. Young 

 strawberries set out on newly broken ground already infested 

 with these grubs would of necessity be seriously attacked. 



Mr. R. A. Cooley says * in this connection, " The remedial 

 measure that seems to promise most is so managing the soil that 

 when it is desired to set out the field to strawberries the beetles 

 will have been previously starv^ed out." He also cites the case 

 of a Alontana fruit grower who was so troubled by this insect 

 that he abandoned strawberry growing entirely some years ago, 

 using the land for other crops. Strawberry plants were started 

 on this same place in the summer of 1904 and were not troubled 

 at all bv these beetles. 



•Montana Agr. Exp. Sta., Bui. 55. 



