BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 
5 
a high degree of control of the codling moth in commercial orchards 
in southern Indiana. Abnormal seasonal conditions resulted in a 
general prevalence of spray injury regardless of treatment, but it 
appeared likely that the nicotine compounds played a comparatively 
small part in producing this injury. In the Pacific Northwest com- 
paratively poor results were obtained with all the nicotine sprays, in 
contrast to the generally favorable results in the sea>on of 1938. No 
adequate explanation for this was found. 
In the laboratory at Vincennes, Ind., a finely divided phenpthiazine 
showed a higher efficiency against the codling moth than a coarse 
material, and was more resistant to rain weathering. Field experi- 
ments with a more finely divided phenothiazine are being conducted. 
Three large-scale orchard tests of tree scraping and banding, carried 
on by the Yakima, Wash., laboratory, gave results consistently in 
line with those of earlier years, the averages being 63 percent clean 
fruit for the sanitation blocks and 47 percent in the check blocks. In 
the orchard in which the work had been carried on for five seasons 
one less spray application was made in the banded block than in the 
rest of the orchard, yet the fruit in the banded block was definitely 
cleaner than that in the untreated parts of the orchard. 
In the orchard used for the biological-mechanical control project 
in West Virginia the percentage of wormy fruit was the least in 1939 
for the last 5 years, in spite of the fact that the apple crop in this 
orchard was likewise very light. The parasitization among codling- 
moth larvae under bands was only 4.7 percent — hardly enough to have 
much value for control. The percentage of larvae destroyed by 
predators under the bands, however, showed a slight further increase. 
From 1936 to 1939 this has gone from 2.3 to 13.3 percent. 
Studies were made at the Yakima, Wash., laboratory of various 
methods of determining the periods when spring-brood codling moths 
emerge and lay eggs. The use of cages, periodic examinations of trees 
for fresh pupa skins, and bait -trap records all agreed reasonably well 
in their indications of the first and peak emergence, but moths con- 
tinued to emerge in numbers from the trees after emergence in the 
cages was complete. Regular examinations of certain branches of an 
apple tree for eggs showed that many eggs were laid during some 
periods when few moths were entering the traps, and that most of 
the eggs were laid after the peak of moth captures in the traps had 
been passed. 
In the Hudson River Valley two sprays of phenothiazine following 
a light arsenical program successful!}' reduced a heavy infestation of 
the apple maggot. Phenothiazine, used in light dosages, and xanthone 
did not reduce heavy infestations of the apple maggot materially, and 
a 15-percent phenothiazine dust was not effective. 
PEACH INSECTS 
The Moorestown, N. J., laboratory continued experiments in mass 
liberation of Macroccntrii* anci/Vrrorns Roll., the most effective orien- 
tal fruit moth parasite available. There was a marked increase in 
parasitization in orchards receiving releases early in the season, and 
subsequent fruit infestation was much lower than in orchards not 
receiving releases. At the end of the 1939 season 12 such releases had 
been made during 3 years, and all but one has been followed by evi- 
