60 



MASS. EXPERIMENT STATION BULLETIN 347 



larvae was collected. This is an average of 16.4 larvae per band. The greatest 

 number taken from one band was 84. Less than a dozen of the trees failed to 

 show any larvae in the bands and these were trees without a crop. 



It is generally recognized that the benefits from treated bands are not realized 

 in full until the season following their application. In this orchard, however, 

 there was a material reduction in the number of stings in the harvested fruit. 

 The larvae destroyed by these bands represent a potential population in 1938 

 of more than 100,000 codling moth larvae figured on the basis of approximately 

 40 eggs per female. It has been estimated that the use of codling moth bands in 

 an orchard with heavy infestation is equivalent to at least one extra spray, and 

 the cost is only a fraction of that of the spray application. 



Apple Maggot Control. (A. I. Bourne and W. D. Whitcomb.) Apple maggot 

 was of comparatively minor importance in 1937. In the well-sprayed commercial 

 orchards there was practically no injury, and even in the smaller home orchards 

 less damage than usual was noted. The insect has receded from the front rank of 

 orchard pests in the last few years. This decline in numbers is due in large measure 

 to timely spraying, more attention to orchard environment, and concerted action 

 on the part of the growers. 



Date of Emergence of Apple Maggot Flies, Waltham 



In Sun In Shade 



Cultivated Sod Cultivated Sod 



Light Soil 



1st fly June 28 June 30 July 2 July 1 1 



25% flies July 15 July 10 July 15 July 20 



50% flies July 19 July 15 July 18 July 23 



75% flies July 21 July 19 July 22 July 26 



Heavy Soil 



1st fly June 29 July 10 June 28 July 10 



25% flies July 12 July 16 July 18 July 17 



50% flies July 19 July 20 July 23 July 19 



75% flies '.V«. July 26 July 25 July 27 July 27 



The percentage of apple maggots which transformed to flies in 1937 (21.37) 

 was the smallest since these records have been taken, and a decrease in the winter 

 survival was indicated for the fourth consecutive year. In spite of this decrease, 

 the influence of soil and atmospheric conditions was consistent with previous 

 records and the greatest emergence was found in the cages having cultivation, 

 light soil, and sun compared to sod, heavy soil, and shade. The first flies appeared 

 in the cages located in the sun, and sod was the most important factor in delaying 

 emergence. The influence of light and heavy soil was less significant than in 

 other years. 



Although the season of 1937 was generally late, the time of emergence of apple 

 maggot flies in the cages corresponded more closely with that of 1936 than with 

 that of 1935. 



Introduction of Parasites of Oriental Fruit Moth in Peach Orchards. (A. I. 



Bourne.) Through a cooperative agreement with the Entomology Department 

 of the Connecticut Agricultural Experiment Station, larval parasites of the 

 oriental fruit moth were available for commercial peach orchards. More than 

 11,000 specimens of Macrocentrus ancylivorus were liberated in late June and early 

 July in 36 peach orchards in 7 counties of the State. 



Although the very mild winter of 1936-37 was a favorable one for the hiberna- 

 tion of insects, early inspection of peach orchards revealed a very light twig 



