Table 1.

Phylogenetic signal in pest sharing between plant host genera

	Coefficients		95% confidence intervals
Pest group (n)	β0	β1	β0	β1
Bacteria (30)	3.2613	−2.9706	1.5581–4.3791	−3.4605 to −2.2215
Fungi (95)	4.3961	−3.3249	3.1958–5.3539	−3.7439 to −2.8019
Oomycetes (32)	2.0763	−2.6679	−0.8020–3.6867	−3.3745 to −1.4216
Insects (637)	3.2441	−2.7004	2.7108–3.7216	−2.9073 to −2.4694
Mites (87)	1.9584	−2.1681	0.3266–2.9620	−2.6039 to −1.4625
Mollusks (37)	−0.4667	−1.1391	−4.5587–1.5261	−1.9896 to –0.5920
Nematodes (70)	2.7157	−2.6249	1.8376–3.4603	−2.9498 to −2.2445
Viruses (108)	8.4044	−5.2014	7.7856–8.9129	−5.4320 to −4.9236
Plants (53)	1.9979	−2.2775	1.0617–2.5609	−2.5233 to −1.8644

Shown are the coefficients of logistic regressions (median and 95% confidence intervals) of whether target host genus was known to be susceptible (S) to a pest from a source host genus, as a function of the phylogenetic distance between source and target hosts. The regression takes the form of logit(S) = β₀ + β₁^*log₁₀(PD + 1), where PD is the phylogenetic distance (time of independent evolution in My) between the source and target host genera. All pest groups except mollusks had phylogenetic signals significantly different from zero (95%CI for β₁ did not overlap 0). The probability that a target host is susceptible to a pest from a source host is then prob(susceptible) = exp[logit(S)]/[1 + exp(logit(S))]. Number of pest species included in the regression (those with >1 known host genus) is given in parentheses as n.