mee ee 
1931 there has been a gradual building up of parasitism by this fungus, ~ 
interrupted only by a drop in percentage of parasitism in 1928 and 1929. 
The average percentage of summer larvae killed in the above-mentioned area 
was over 9 per cent in 1931, as compared with 0.5 per cent in 1929 and a 
much lower figure in 1924." 
S. F. Potts and Russell R. Whitten, Melrose Highlands, are continu-— 
ing fumigation experiments begun last spring with hydrocyanic acid gas to 
ascertain under what conditions and at what dosages hibernating satin moth 
larvae may be killed without injury to the trees on which they occur. Mr. 
Potts states: "It may be interesting to know that a partial vacuum and an 
air pressure as high as 150 pounds per square inch had little effect on 
the several species of lepidopterous larvae dealt with." According to Mr. 
Whitten the percentages of hibernating larvae killed in the cement—block 
compartment under various conditions of fumigation, as indicated by exam— 
inations of material, were as follows: 


Per cent 
Sodium cyanide, 5 oz. per 1,000 cu. ft., 70-74° F., 6 hrs. exposure, 16.8 
YW Lai 5 W Lai 1,000 Ww " 80° F. 6 Ww ia] 18.9 
" Ww 10 " " 1,000 Ww Al 60—63° F. } 24 tt ‘a TOR CO 
! ! 10 " wt 1 ; 000 Ww " 80-83° F Bah 24 wt " 
Regarding spray experiments with the European pine shoot moth 
(Rhyacionia buoliana Schiff.), in which C. M. Symonds assisted, C. E. 
Hood, Melrose Highlands, states that "periodical examination of the buds 
from the spray plots at Brookline, Mass., were made this month, and it was 
found that 57.1 per cent of the terminal buds in the sprayed plots were 
injured, while in the check plots 100 per cent of the terminal buds were 
injured. In the sprayed plots 14.4 per cent of the secondary buds were 
injured, as against 26 per cent in the check plot." Various strengths of 
lead arsenate, with fish oil added, were used in spraying these plots. 

—— 

CEREAL AND FORAGE INSECTS 
Reporting on investigations of the corn ear worm (Heliothis 
obsoleta Fab.) at Charlottesville, Va., W.vJo Phillips saya "The 
fall emergence of ear worm moths has been unusually high. We have re-— 
covered a total of 877 moths from our hibernation cages. This emergence 
was from a total of 10,000 larvae that we placed in our cages last month. 
Fmergeuce for the same period last year was 489 moths recovered. We 
believe the extremely hot weather the first part of the month was respon— 
Sible for the high emergence." 
"Information was recently obtained" by C. H. Batchelder, Arlington, 
Mass., "concerning the length of time necessary to kill second~generation 
European corn borer larvae of the fifth instar when exposed to temper-— 

