RESULTS 



1964 tests . — Very good results of the treatments are shown in table 1. Vapor 

 concentrations at 2 ft. and 14 ft. above the floor in the center of the cellar never 

 exceeded the 28 ^ug/cu. ft. accepted as the threshold limit of safetj^ for workers in a 

 treated area by the American Conference of Governmental Industrial Hygienists. 

 Vapor concentrations were lower in the third test, since this cellar had almost twice 

 the amount of air space as the first cellar and it also had a few open windows. 

 Readings were very low after 24 hours . 



In the first test, mortalities of caged drosophila in seven locations ranged from 

 88 to 100 percent, with an average of 95 percent. Mortalities were 100 percent in all 

 locations in the second and third tests. Insects survived only at locations 24 feet 

 above the floor. 



The results of the 1964 tests indicated that it would be advantageous to use the 

 vapor generator in wine cellars . 



1965 tests . — The short daily treatments made with the vapor generator in 1965 

 gave good results (table 2). The tests were made in the smaller cellar. 



During the third day of operation, CO2 that drifted into the cellar from a near- 

 by fermentation room may have increased the mortality of the drosophila in the 

 cellar and cages, since they are very susceptible to carbon dioxide. Cages of dried- 

 fruit beetles were used the last 2 days instead of drosophila since they are not as 

 susceptible to CO2. However, no CO2 was detected during these days. Trap counts 

 of drosophila remained low during the entire period, and vapor concentration 

 readings were at a very safe level. 



1966 tests . — The effect of vapor generator treatments for an entire season on 

 drosophila populations inside a wine cellar is shown in table 3. After the first 

 several weeks, significantly fewer flies were trapped in the treated area than in the 

 untreated areas. Although the trap counts indicated a gradual buildup of flies in 

 untreated areas, populations remained constantly low in the treated area. Although 

 the highest daily trap catch remained fairly low, a rather rapid reduction in the 

 amounts of dichlorvos produced by the vapor generator occurred (table 4) . 



The generator did not maintain its early rate of vapor production. There was 

 approximately a four- fifths loss in amounts of dichlorvos vapors produced after only 

 17 1/2 hours of operation. After 61 hours of operation, vapor concentrations 

 produced in the wine cellar by 2 hours of operation were approximately 5 jug/cu. ft. , 

 compared with 48 to 56 /^g/cu. ft. during the first hours of operation. Part of the 

 rapid decline in vapor production maj^ have been caused by the deterioration of the 

 pellets by constant exposure to air. The cover of the generator remained off during 

 the entire period of operation. 



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