Table 3. Overview of datasets on the differences in level of herbivory between native and non-native insects, using the community (52–64) or the biogeographical approach (65–68).

Indicated are for each dataset the plant sample size (number of native/non-native plant species), the mean difference in insect diversity (number of species), and the standardized mean difference in insect diversity (± 95% confidence interval). Overall outcome of random effects (RE) model indicated in italics. Significant differences are indicated in bold.

Dataset and reference		Sample size (native/non-native plants)	Mean difference in herbivore level (native–non-native)	Standardized mean diff. (± 95% CI)
Community approach
52	Agrawal & Kotanen (2003)	15/15	−1.66	−0.17 [−0.89, 0.54]
53	Carpenter & Cappuccino (2005)	30/39	1.20	0.61 [0.12, 1.10]
54	Cincotta, Adams & Holzapfel (2008)	1/1	−1.16
55	Harvey et al. (2015)	5/5	0.08	1.11 [−0.22 , 2.45]
56	Heard & Sax (2013)	6/6	−17.23	−2.31 [−3.77, −0.85
57	Hill & Kotanen (2010)	20/15	0.62	0.77 [0.09, 1.47]
58	Lieurance & Cipollini (2013)	1/1	19.73
59	Liu, Stiling & Pemberton (2007)	2/1	0.06
60	Liu, Stiling & Pemberton (2007)	2/4	0.14	10.28 [4.22, 16.34]
61	Lombardero, Vázquez-Mejuto & Ayres (2008)	1/1	12.60
62	Meijer et al. (2015)	6/11	6.55	0.6 [−0.41, 1.62]
63	Meijer et al. (2015)	12/4	2.47	0.61 [−0.54, 1.76]
64	Schutzenhofer, Valone & Knight (2009)	1/1	9.08
	RE model	102/104		0.91 [−1.89, 3.70]
Biogeographical approach
65	Adams et al. (2008)	1	5.02
66	Cripps et al. (2010)	1	25.80
67	Vilà, Maron & Marco (2005)	1	19.79
68	Wolfe (2002)	1	24.00