Table 3.
GLMM-estimates of total count (winged + unwinged morphs) of aphid species specialised on Tanacetum vulgare in calendar week 25 of 2021.
| Response variable | Uroleucon tanaceti | Macrosiphoniella tanacetaria | Metopeurum fuscoviride | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total count (abundance) b | Total count (abundance) a | Total count (abundance) a | |||||||||||
| Level | Individual plant level | Plot level | Individual plant level | Plot level | Individual plant level | Plot level | |||||||
| Fixed Effects | d.f. | Χ2 | Effect | Χ2 | Effect | Χ2 | Effect | Χ2 | Effect | Χ2 | Effect | Χ2 | Effect |
| Shannon diversity | 1 | 0.61 | – | 3.90* | ↓5 | 3.90* | ↑ | 0.15 | – | 1.00 | – | 0.25 | – |
| Shoot length | 1 | 0.87 | – | 8.28** | ↑ | 0.02 | – | 3.17 | – | 2.08 | – | 0.25 | – |
| Number of shoots | 1 | 0.03 | – | <0.0001 | – | 0.02 | – | 0.004 | – | 0.01 | – | 10.29** | ↓ |
| Number of leaves | 1 | 16.24*** | ↑4 | 0.31 | – | 3.31 | – | 0.45 | – | 4.75* | ↑ | 0.94 | – |
| Number of shoots with inflorescences | 1 | —2 | — | — | — | 0.14 | – | <0.0001 | – | 0.15 | – | 1.94 | – |
| Ant presence | 1 | — | — | — | — | — | — | — | — | 52.49*** | ↑ | 14.57*** | ↑ |
| Random Effects | Variance [%]3 | Variance [%] | Variance [%] | Variance [%] | Variance [%] | Variance [%] | |||||||
| Block | 1 | 2.72 | 17.65 | 18.65 | 21.50 | <0.0001 | <0.0001 | ||||||
| Plot | 1 | 29.65 | — | 13.77 | — | 21.24 | — | ||||||
| Mother plant | 1 | <0.0001 | — | 1.24 | — | x6 | — | ||||||
response variable was modelled using a negative binomial 1 distribution.
response variable was modelled using a negative binomial 2 distribution.
1 p-values were estimated using a type-3 Wald chi-square test.
2Effects marked with long hyphen were left out of the model due to being inapplicable for the model.
3Variance [%] of random factors displays the percentage of the total variance that is explained by the random factors.
4↑ display a positive relationship with the fixed effect.
5↓ displays a negative relationship with the fixed effect.
6Random effects marked with “x” were left out of the model due to causing model convergence problems.
The Χ2 estimates are based on Wald’s type 3 chi-square test, numbers in bold font indicate significant effects, asterisks display the significance level (*p< 0.05; **p< 0.01; *** p< 0.001). Results of winged presence were moved into the supplement since no significant effects were found. Total number of plants on which aphids were scored: 291.