The Bulletin. 35 



seedbed to the field, where they often do a great deal of damage to the 

 plants just after they have been transplanted and in their weakened 

 condition. 



Food Plants. — The Tobacco Flea Beetle seems to be able to live and 

 thrive upon any plant of the potato family. It has been recorded by 

 others or observed by the writer upon the following wild plants: 

 ground cherry, nightshade, horse nettle, jimson weed and matrimony 

 vine, and also upon the following cultivated plants : tomato, potato, 

 tobacco, and eggplant, although jimson weed seems to be preferred 

 among the wild plants and tobacco among the cultivated. 



Control. 



Preventives. — Care should be taken to keep down all weeds of 

 the potato family in and about the tobacco seedbeds and fields. This 

 applies especially to the early weeds of this group. 



Remedies. — Arsenate of lead seems to be the best remedy to be 

 used against this pest. In the seedbeds it may be used very strong. 

 8 to 10 pounds to 50 gallons of water without any apparent injury 

 to the plants. In the fields later it must not be used stronger than 

 6 pounds to 50 gallons; and still later in the season, especially 

 during hot weather, it should not be used stronger than 4 pounds to 

 50 gallons, as stronger solutions than this may cause slight injury 

 to the leaves by burning. Weaker solutions than 4 pounds to 50 

 gallons do not seem to be effective. It is very profitable, however, 

 to use the stronger solutions in the seedbeds, as the plants are at this 

 time confined to a small area and set close together, so that very little 

 of the solution would be wasted. Furthermore, it is evident that the 

 destruction of beetles at this season not only means stronger and 

 healthier plants, but it also means that the succeeding generations 

 of the Tobacco Flea Beetle in the field will be greatly decreased. 



If Paris green is used, it should be used somewhat stronger than 

 recommended for horn worms. Growers report favorable results 

 from using 1 pound of Paris green to 125 gallons of water, although 

 there is a slight tendency for this stronger solution to burn the foliage. 

 The addition of a pound and a half of stone lime to this mixture 

 would help to counteract the burning. 



Our preliminary experiments in seedbeds showed very favorable 

 results from spraying with kerosene emulsion at a strength of 10 

 per cent oil. The leaves of the young plants were not injured by this 

 mixture except where the plants were simply drenched, and the re- 

 duction in the number of Flea Beetles was more noticeable than where 

 the stronger solutions of arsenate of lead were used. This sub- 

 stance, however, is still in an experimental stage, and if used at all 

 should be very carefully made and applied at first only in an ex- 

 perimental way. If beneficial results are secured from the pre- 

 liminary spraying, it may then be used more extensively. 



