
than in the previous year and also by the fact that because of abnormally 
high temperature the weather during the first week in August was gen- 
erally unfavorable for beetle response. The traps were withdrawn during 
the period August 18-23, as the last complete collection from the 400 
traps on August 15 totaled only 83,000 beetles," 
Root crops grown in soil treated for Jap. beetle grubs contain 
arsenic.—— Reporting on the control of Japanese beetle larvae in truck 
crops, F. E. Baker, Moorestown, says: "The various truck crops growing in 
the experimental garden containing plots treated with lead arsenate 
at the rates of 1,000, 1,500, and 2,000 pounds per acre have been har— 
vested and analyzed as they matured. The indications at the present 
time are that the majority of vegetables grown produce normally, even 
in these strong dosages. However, string and lima beans were defin— 
itely injured by the treatment. Analyses to date show that all root 
crops, such as radishes and turnips, contain more than the legal tol- 
erance of arsenic, whereas other crops bearing the edible portion above 
ground, such as tomatoes and egg plants, although containing some ar-— 
senic, are well below the legal tolerance of 0.01 grain per pound." 
TRUCK CROP AND GARDEN INSECTS 
Correction.-—— In the July 1933 Monthly Letter p. 4, line 40 should 
read —— larvae of the southern armyworm were used. 
Qn the control of Fuller's rose beetle.-- H. H. Richardson, of 
greenhouse-insect investigations, Washington, D. C., reports: vin 
studies on the effectiveness of various insecticides against Asynonychus 
godmani Crotch the preliminary tests indicate that the beetles are very 
sensitive to the action of pyrethrum powder, which produces a quick 
paralysis and great irritation, accompanied by considerable regurgita-— 
tion. The beetles become moribund but do not die for considerable 
lengths of time--two weeks or more. The arsenicals apparently exert a 
deterrent effect and beetles do not feed on treated foliage. Beetles 
caged on foliage dusted with lead arsenate got the dust on their tarsi 
and were slightly affected but did not die for 10 or 12 days. Both 
sodium fluoaluminate and barium fluosilicate dusts are very promising 
and their killing action was much faster." 
Parasitization of beet leafhopper on Russian thistle higher in new 
Lawson "investigated some 15 fields of Russian thistle in the Mendota 
area with the view of determining the correlation between extent of para-— 
Sitization and the age of field, size of thistle, and population of 
Eutettix tenellus Bak. present. The indications are that there is no 
correlation except that parasitization runs higher in new fields the first 
year. This is evidence against the probability of parasites building up 
in old fields by hibernating there. Mr. Lawson had previously observed 
that E. tenellus populations in low thistle are almost negligible, and the 
investigations in these fields bore this out. It is probable that the 
