120 



PP199 at .04% level. These chemicals proved statistically inferior to 

 the first group of compounds, while the test was not sensitive enough 

 to establish differences with the second. 



A comparison across the weeks (Figure 34) shows I.C.I. 's product 

 PP067 at ,01% as losing its effectiveness as early as during the second 

 week. This control continued to decline until the sixth week when it 

 was found to be the least effective chemical tested. No significant 

 difference could be found for any of the other chemicals during week 2, 

 Dupont's chemical, oxamyl , was significantly less effective in control 

 of the citrus rust mite during week 3 than any of the other chemicals. 

 Oxamyl at the sixth week demonstrated moderate control (Figure 34). 

 PP067 at ,02% was a moderate control chemical during weeks 3 and 6. 

 1,0,1, 's products PP199 at ,01% and PP067 at ,04% both maintained 

 effective control for the first 3 weeks. At week 6, however, both 

 chemicals had lost effectiveness and were rated least effective. 

 PP199 at .005% lost effectiveness only after the third week and became 

 moderately effective. Only three treatments maintained their effective- 

 ness throughout the six week period. The chemicals were PP199 at 

 .02%, dicofol, and PP199 at .04%. No statistical difference could be 

 found between these chemicals for control of the citrus rust mite. 



1976 field acaricidal spray test . As in the 1975 evaluations an 

 analysis of variance, ANOVA, for significant differences between the 

 control data and the chemicals proved statistically significant. This 

 significance allowed for further statistical evaluations using only the 

 toxicants which increased the sensitivity of the tests. A Poisson dis- 

 tribution existed so all data was transformed prior to evaluation 

 (Table 30). 



