NOY Sv 
JAPANESE BEETLE AND ASIATIC BEETLE RESEARCH 
Corrections: (1) In the September issue of the Monthly Letter 
the latter half of the third paragraph refers to the Japanese beetle; 
(2) The note about R. M. Burrell should indicate that he is to continue 
in Japan studies of parasites of scarabaeids. 
Outstanding features of the control investigations of the Japanese 
beetle during October, according to W. E. Fleming, of the Moorestown, N. 
J., laboratory, include the completion of a grub survey of turf experi- 
ments at Swarthmore, Pa., where "all the grass plots which had been treated 
jast June were examined to determine the density of the grub population 
in the soil. A total of 430 diggings were made. M. R. Osburn reports 
that the average number of Popillia larvae in the Swarthmore campus was 
52.5 to a square foot on the untreated grass, 21.1 on the plot sprayed 
with lead arsenate, and from 11.1 to 23.6 on the plots dusted with dif— 
ferent mixtures of lead arsenate and the carrier. A larval survey on 
the hockey field at Swarthmore College showed an average of 45.1 larvae 
to a square foot. The College treated this field in October. L. Koblit-— 
sky analyzed 220 samples of the treated soil from the plots at Swarth- 
more and found practically all of the arsenic in the upper inch of soil. 
The penetration of the liquid applications was slightly better than the 
dry application." 
"A larval survey, under the supervision of W. E. Fleming and F. E. 
Baker, has been compieted on the four nursery plots containing evergreen 
and deciduous stock, the soils being maintained at dosages of 1,000, 
1,500, and 2,000 pounds of lead arsenate per acre in the upper 5S inches 
of three, and the fourth remaining untreated. The survey showed an av— 
erage of 1 Popillia larva in 210 square feet in plots having 1,000 pounds, 
and no Popillia in the plots having 1,500 and 2,000 pounds; the infest— 
ation in the untreated plot averaged 1 Popillia larva to 1.5 square feet. 
Two larvae recovered in the 3,000-—pound plot were identified by R. J. 
Sim as Phyllophaga gracilis Burm." 
The final observations on different varieties of hydrangeas growing 
in soil treated with barium fluosilicate have been made by W. E. Fleming 
and F, E. Baker. Mr. Fleming states: "There is considerable variation 
in the resistance of different horticultural varieties to the action of 
barium fluosilicate. Only one variety grew in a dosage of 3,000 pounds, 
two in 2,500 pounds, six in 2,000 pounds, and ten in 1,500 pounds of bar— 
ium fluosilicate per acre." 
"Tw. tests have been made" at Moorestown by E. R. Van Leeuwen, "to 
determine the effect of centrifugal force on the larva of the Japanese 
beetle. Fifteen larvae were whirled for 10 minutes at 1,700 revolutions 
per minute, and an equal number for the same period at 3,200 revolutions. 
Two larvae survived in each treatment." 
J. W. Lipp is carrying on a series of experiments at Moorestown 
to determine the value of injecting dilute carbon disulphide emulsion 
