70 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



of the first symptoms of the poison, the beetles have consumed a killing 

 dose. Based upon this idea sprays were prepared containing 5 lbs. of 

 lead arsenate to 50 gallons plus 1 to 5 lbs. of flour, gelatin, or glue to 

 coat over the particles and delay the action of the arsenic. These 

 sprays spread evenly over the foliage covering the surface with a large 

 dose of coated particles of lead arsenate. Using sprays and collecting 

 the beetles as they left the plants, a kill of 60 to 70 per cent, was obtained 

 under field conditions. Collections of beetles in the field after sprayin? 

 may be divided into several groups. 



First: — Beetles which have not fed on the sprayed foliage, of these 

 from. 20 to 40 per cent, of the males and to 20 per cent, of the females 

 will die, probably due to poison they obtain from cleaning their bodies 

 and in particular their mouth parts while the spray is drying. 



Second: — Beetles which after feeding fly away within 30 minutes 

 from the time of spraying. In this group 40 to 70 per cent, of the males 

 and 60 to 80 per cent, of the females die. 



Third :^ — Beetles still on the plants 1 to 2 hours after spraying of 

 which, from 50 to 70 per cent, of both males and females die. 



In conclusion, the season's work may be summed up as having shown 

 that the Japanese beetle is repelled by the toxic effects produced by 

 having eaten some of the sprayed foliage; that a certain percentage 

 of beetles may be killed under field conditions by the use of large quanti- 

 ties of the arsenical evenly distributed over the foliage; and that in 

 the case of sprays, the even distribution of the arsenical may be obtained 

 by the use of flour, glue, or gelatin, which materials by coating the 

 particles of the arsenical probably increase their efficacy. Whether 

 the use of an arsenical will be successful for large scale control in the 

 field remains to be determined during the coming season. 



Summary 



Japanese beetles are not repelled from sprayed foliage by the color, 

 physical condition, or taste of the arsenical. 



The beetles appear to be repelled by the toxic s}-mptom.s resulting 

 from eating some of the arsenical. 



Large quantities of the arsenical evenly distributed over the foliage 

 will result in a certain percentage of the beetles eating a killing dose 

 before the toxic symptoms develop. 



A certain percentage, particularly of the males, die without having 

 eaten of the sprayed fohage, probably due to spray material obtained 

 in cleaning their bodies and mouth parts. 



President George A. Dean : These papers on the Japanese Beetle 

 are now open for discussion. 



