ANALYSIS OF DATA 



Statistical distribution: Comparisons of infestations , populations, and other categories 

 can be made on the basis of their statistical distributions. In this study, analysis of distribu- 

 tions was based upon scatter diagrams of variance plotted over means of the three variables 

 measured. 



The scatter of variance in relation to mean attack density and gallery length appeared to 

 be random. Comparison of Wasatch and Teton data (figs. 2, 3, 4, and 5) showed no difference 

 in distribution. The brood data, however, typified a contagious distribution- -increasing vari- 

 ance with an increase in the mean (figs. 6, 7). There were not enough data to determine the 

 specific contagious distribution involved. 



> « 



> y 



Figure 2. --Teton plot 

 --attack density: x 

 for 1/10 sq. ft. 

 rectangular sam- 

 ples, o for 1/2 sq. 

 ft. samples. 



8 10 12 14 

 2 



Mean Attacks Per Ft. 



16 



18 20 



X X 



Figure 3. --Wasatch 

 plot --attack den- 

 sity: X for 1/10 sq. 

 ft. rectangular 

 samples , o for 1/2 

 sq. ft. samples. 



4 6 8 10 12 14 16 18 20 



2 



Mean Attacks Per Ft, 



3 



