224 Maine Agricultural Experiment Station. 1917. 



Stirring the Soil. 



To determine, what effect stirring the ground would have 

 on the pupae, 50 puparia were placed in clay soil, which had 

 been previously loosened to a depth of three inches under a 

 cage. Several times a week, the clay was stirred with a rake. 

 Nine fruit flies emerged from May 25-June 3. 



Effect of Chemicals on or in Soil. 



It is claimed that "as the larvae find fine dry dusty sab- 

 stances prejudicial to their transformation a heavy dressing cf 

 coal ashes placed under the bushes in June would destroy many 

 of the larvae***." One hundred maggots after issuing from 

 currants were dropped into a jar containing six inches of sifted 

 wood ashes. Several weeks later 61 perfectly formed puparia 

 were counted and 39 dead pupae and shriveled larvae were 

 found in the ashes. Under field conditions the maggots prob- 

 ably would have burrowed through the ashes and entered ihe 

 ground to pupate, and it is questionable whether the death rate 

 would have been as high as in the jar of ashes. 



One farmer had placed coal and wood ashes on the ground 

 below currant and gooseberry bushes for several years each 

 spring and the ashes had formed a hard crust. An examination 

 of the crop, however, showed the presence of maggoty fruit, 

 but the infestation was not so severe as in the case of currant 

 and gooseberry bushes which had not been treated in this man- 

 ner situated in dooryards about 315-565 feet distant. In the 

 following season, 26 trypetids issued from May 27-June 2, in 

 5 ground cages covering 11 square feet of ashes which had been 

 hoed below white currant bushes, A ground cage, tw;o feet 

 square, was placed over compact ashes between two gooseberry 

 bushes, but not an adult was found in the cage during the season. 



A method to control the Mediterranean fruit fly suggested 

 in Malta in 1889, was to strew "the surface of the ground with 

 one part of sulphate of iron to 24 parts of sand, the ground to 

 be subsequently watered." In our experiment one quart of 

 infested gooseberries was placed on the surface of one part of 

 finely-powdered sulphate of iron mixed with 24 parts of sand, 

 the mixture being subsequently watered. Several weeks later, 



