Table 1. Interactions among groups of arthropods on the host plant Baccharis dracunculifolia. The link codes refer to interactions depicted in Fig. 2, and the relevant statistical tests are presented in Table 2. G7 and G10 refer to the gallers Baccharopelma dracunculifoliae and Rachiptera limbata, respectively.
Link code Link type Affecting Effect* Affected Detection method Statistics (see Table2)
Node modulation Node modulation
1 Direct interaction Aphid (inside galls) Negative Galler G7 Gall dissection lines 7, 8
2 Direct interaction Aphid (inside galls) Negative Parasitoids of galler G7 Gall dissection line 9
3 Direct interaction Aphids (on branches) Negative Host plant Observation NA (herbivory)
4 Direct interaction Galler G7 Negative Host plant Gall counting NA (herbivory)
5 Direct interaction Galler G10 Negative Host plant Gall counting NA (herbivory)
6 Direct interaction Parasitoid Negative Galler G7 Gall dissection NA (parasitism)
7 Direct interaction Parasitoid Negative Galler G10 Gall dissection NA (parasitism)
8 Density effect Ants (exclusion) Negative Volume of Gall G7 x Nymph abundance Node removal line 6
9 Density effect Ants (exclusion) Positive Predator abundance Node removal line 2
10 Density effect Galler G7 (exclusion) Positive Predator abundance Node removal line 2
Link modulation Link modulation
11 Three-way interaction Ants (exclusion) Positive Link Aphid x Galler G7 Modifier removal line 4
12 Three-way interaction Ants (on branches) Positive Link Parasitoid x Galler G7 Modifier density line 13
13 Three-way interaction Ants (on branches) Positive Link Galler G10 x Host Plant Modifier density line 16
14 Three-way interaction Ants (on branches) Negative Link Aphid x Host Plant Modifier density line 1
15 Three-way interaction Aphids (on branches) Negative Link Parasitoid x Galler G7 Modifier density line 15
16 Three-way interaction Hatched Gall G7 Positive Link Parasitoid x Galler G7 Modifier removal line 5
17 Three-way interaction Hatched Gall G7 Positive Link Aphid x Galler G7 Modifier density line 11
18 Three-way interaction Hatched Gall G7 Negative Link Galler G10 x Host Plant Modifier density line 17
19 Three-way interaction Hatched Gall G7 Positive Link Parasitoid x Galler G10 Modifier density line 19
20 Three-way interaction Herbivore abundance Negative Link Galler G7 x Host Plant Modifier density line 12
21 Three-way interaction Parasitoid Positive Link Aphid x Galler G7 Gall dissection line 3
22 Three-way interaction Predator abundance Positive Link Parasitoid x Galler G7 Modifier density line 14
23 Three-way interaction Predator abundance Positive Link Aphid x Galler G7 Modifier density line 10
24 Three-way interaction Predator abundance Positive Link Galler G10 x Host Plant Modifier density line 18
25 Four-way interaction Galler G7 Positive Link 14 Modifier removal line 1
26 Four-way interaction Hatched Gall G7 Positive Link 13 Modifier removal line 16
27 Four-way interaction Hatched Gall G7 Positive Link 12 Modifier removal line 13
28 Four-way interaction Hatched Gall G7 Positive Link 20 Modifier removal line 12
29 Four-way interaction Hatched Gall G7 Positive Link 23 Modifier removal line 10
Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link. *Positive and negative modulation respectively strengthens and weakens a link.