Table 2. Test statistics for the bi-trophic experiment.
| Aphis gossypii | Uroleucon macolai | |||||
| Effect | DF | F or χ2 | P | DF | F or χ2 | P |
| A. Genotype analysis 1 | ||||||
| Competition (C) | 1,13 | F = 2.04 | 0.18 | 1,13 | F = 8.94 | 0.01 |
| Genotype (sex) (G)2 | 1 | χ2 = 9.8 | 0.0017 | 1 | χ2 = 1.2 | 0.27 |
| C×G2 | 1 | χ2 = 0 | 1.00 | 1 | χ2 = 0.2 | 0.66 |
| B. Sex analysis 1 | ||||||
| Competition (C) | 1,72 | F = 1.78 | 0.19 | 1,73 | F = 9.30 | 0.003 |
| Plant sex (PS) | 1,72 | F = 10.77 | 0.0016 | 1,73 | F = 1.24 | 0.27 |
| C×PS | 1,72 | F = 0.41 | 0.52 | 1,73 | F = 0.34 | 0.56 |
1
Analysis of both genotype effects (A) and plant sex effects (B) include greenhouse bench and aphid counter as random effects.
2
Tests for the effects of genotype and competition×genotype are made with log-likelihood ratio tests (based upon χ2) and genotype is nested within plant sex.