he 
B= 
The: results on seasonal: fluctuations as summarized from the records 
of the periodic series of surveys are given below: 
:Average larvae per 
Date sss square foot 

Stations 
(Golf courses:at) 
ee ef 

tL Cri, . . Number 
Moorestown, N,J»---~---------- ea 45 say a 
Merenentville, Ned»@----—---<-- met x ; 203 
Re aa terae pateees an tana, Led 
Beeceks” Ny Jp aoe ee eae : 149 
; ; Apre 12- ‘ ye 
Jenkintown, Pa g~-----~-- vapid : ees : ee 
St. Martins, bts Sma: il ie : ae ra 
Torresdale, Pa.---~-~-~- prs ieee fs he 
Burlington C00, NeTyo-----= n=! rake oy tee 
Hopewell, N.J.---------------- ade z are Mia 
‘Philmont, Pa.---------- nonce a ae 
Springdale, NeJe es x2 setae 
Comparison of the results given in these two tables fail to indicate 
that the unusually cold weather of February 19434 reduced the population 
of Japanese beetles in the’soil. Instead, a reduction of about 3 per~ 
cent in the periodic ‘surveys, apparently ‘no greater than the normal re~- 
duction in a mild winter, characterized the unusual winter just paste 
This’ view is-quite in line with the indications afforded by the evidence 
from both the seasonal and periodic series of surveySe 
Stomach poisons for Jap beetle in soil.--Tests were continued by We 
Be Fleming, Fe Ee Baker, and Le. Koblitsky, Moorestown, with third-instar 
larvae under controlled conditions using various materials as stomach 
poisons. Samples of chemically pure and 90 percent rotenone, derris con= 
taining 4 percent rotenone, and pyrethrum were tested at rates ranging 
from 500 to 5,000 pounds per acre without any indication of these materials 
being toxic to the larvae. Basic lead arsenate. at the rate of 10,000 
pounds per acre and hydrated lime at the rate of 25,000 pounds per acre 
were not injurious to the larvae, Tests made with various samples of 
acid lead-arsenate containing from.40e5 to 33.0 percent arsenic pentoxide 
showed that the difference in the arsenic content within this range did 
not significantly change the insecticidal action of the material on larvae 
in the soils 
