Appendix H. Stepwise multiple regression with backwards removal for the effects of plant resistance traits (cardenolides, latex production, trichome density, and leaf toughness) and leaf nitrogen, plant height and percentage flowering on abundance of Tetraopes adults. The analysis is based on the family means for 23 full-sibs of Asclepias syriaca grown in a common garden.
Effect
R^{2}
Coefficient
Standard Error
t
P
Percentage flowering
0.099
1.586
0.499
3.179
0.005
Trichome density
0.084
-0.008
0.003
-2.938
0.009
Maximum height
0.083
0.080
0.028
2.920
0.010
Nitrogen
0.060
-1.030
-0.414
-2.488
0.023
Latex volume
0.052
-0.245
0.106
-2.305
0.034