220 THE CANADIAN ENTOMOLOGIST <► 



in the soil, also that the use of organic manure and especially 

 compost should be avoided. 



From these two accounts it is evident that Popilia japonica 

 is regarded as a pest in Japan. It was probably introduced into 

 New Jersey in the larval stage in the soil around iris roots imported 

 from that country. Japanese iris roots were first planted in the 

 nursery where the infestation occurred about six years ago, and 

 there have been two or three plantings of similar stock since that 

 time. Azaleas imported from Japan have also been planted in 

 this block but not previous to two years ago. Judging from the 

 number of beetles observed, the insects must have been present 

 more than two years. That it was not noticed sooner is due to 

 the fact that its feeding is largely confined to weeds as has been 

 stated. Its rate of dispersal is apparently very slow, as at the 

 present time its feeding in the nursery is confined largely to that 

 part where it apparently originated, and in the weeds outside of 

 the nursery along the road it has not extended more than a few 

 hundred yards. The fact that its rate of dispersal is slow is for- 

 tunate since if it became widely distributed it might become a 

 serious pest on plants of the family Polygonacece such as buck- 

 wheat, and of the family VitacecB, such as grapes and perhaps on 

 plants of other families such as cherry, etc. 



While the Japanese account states that this insect infests 

 leguminous plants, it is interesting to note that these plants re- 

 mained uninfested although other plants in their midst were 

 badly eaten, as has been mentioned above. The infestation in 

 New Jersey is under careful observation; infested weeds and nursery 

 plants are being treated with arsenic supplemented by hand pick- 

 ing. In this connection, it is interesting to note that where Ampe- 

 lopsis was sprayed with arsenate of lead, the plants were practically 

 free from the beetles, although previous to the spraying they were 

 badly infested. No dead beetles were observed on the ground un- 

 der the sprayed plants, but after careful observation it was found 

 that some of both sexes had burrowed several inches into the soil 

 under the infested plants. These beetles were very sluggish and 

 had apparently been affected by the poison. 



The beetle can be recognized from the following brief de- 

 scription: It measures a little less than one-half inch in length 



