90 SOME INSECTS INJURIOUS TO TRUCK CROPS. 



dance of the beetles, which are found in light, sandy, and heavy soils. 

 Mr. Qiiayle further says: 



The control measures which have been tried have been necessarily directed 

 entirely against the adult or beetle, and considering the rapid growth of the 

 vines and the continuous appearance of the beetles no effective and practical 

 remedy has yet appeared. With further work on the younger stages it may 

 be possible to find here a vulnerable point of attack. 



One of the most j^romising remedies for this as well as other insect 

 pests is the employment of clean methods of culture. Since it has been 

 found that the flea-beetles ensconce themselves in any available shel- 

 ter, such as the cracks in the hop poles, even although these may have 

 no bark remaining, it has been thought desirable to dip the poles in 

 a preparation which will not only close the cracks but which will also 

 repel the pests. Fuel oil, a grade of crude petroleum, is being tried, 

 according to Mr. Eder, since it can be purchased as low as 2 cents 

 a gallon. Tar might serve the same purpose and should act as 

 strongly as a repellent and close the cracks more closely and would 

 not be so disagreeable to handle. The poles are dipped into the 

 boiling fuel oil, but the tar would also have to be heated very hot 

 before dipping. 



It is customary to plow thoroughly and to cultivate where possible 

 so as to keep down the weeds, and this method of tillage must, of 

 course, be continued, as the insects find food in weeds of the kind 

 which h^te been mentioned in the opening paragraph, viz, dock, 

 lamb's-quarters, pigweed, and the like, and also cruciferous weeds. 

 If, by preventing the insects from hibernating in the hop fields in 

 debris, the fields can be practically freed from them, the next step 

 is to prevent their hibernating in near-by timber, as there can be 

 little doubt that in such places are their favorite winter quarters. 

 It is practicable in many cases to cut down small sections of timber 

 in order to accomplish this purpose. 



In answer to the question as to the remnants after the hops are 

 picked, Mr. Eder informed the writer that the expedient of cutting 

 the tops and destroying them by burning led to the discovery that the 

 beetles enter into the hollow stalks, remaining in hibernation there 

 in great numbers. With the discovery of this habit he will permit 

 remnants to remain as long as there is any prospect of the insects' 

 trying to obtain winter shelter in them, and then will have all debris 

 burned at about the time of the first frost. One method of destroy- 

 ing field remnants and weeds, by sheep pasturage, is illustrated by 

 Plate" VI. 



The writer has suggested the addition of burlap wrapped about 

 the poles which have been treated with tar or which do not have an 

 odor strong enough to repel the insect. This will attract the insects 

 for hibernation, and can be removed after the first frost, or there- 



66 — VI 



