Supplementary Material
Appendix 1: Spatial autocorrelation and sensitivity analysis.
Table S1:Characteristics of pine species included in the present survey.
Table S2: Summary of PGLS models.
Appendix 1: Spatial autocorrelation and sensitivity analysis.
The Arboretum National des Barres was not initially designed for research purpose. Trees were not randomly planted and were divided into two gardens. We tested whether there were correlations between geographic and phylogenetic distances using Mantel's correlation tests which estimate correlations (based on Pearson's coefficient) between two distance matrices. Geographic distance matrix was computed calculating Euclidean distances between every pairs of pines within the arboretum. Phylogenetic distances corresponded to the sum of branch lengths joining every pairs of trees within the phylogenetic tree (i.e., twice the age of the most recent common ancestor shared by two species). We used Mantel's correlograms to test how Mantel's correlations scaled with geographic distance. Analyses were done in R with functions mantel and mantel.correlog from packagevegan (Oksanen et al. 2016).
Euclidean distances between pines were on average 326m (range: 2 – 952m) which is far below dispersal capacities of PPM female moths (> 1.9 km on average, Battisti et al. 2015). Overall, there was a significant but weak correlation between Euclidean and phylogenetic distances (Mantel's r = 0.09, P = 0.001) that decreased with geographic distance. This pattern was driven by one of the two gardens (r =0.19, P =0.001, Figure S1). In the second garden, Euclidean and phylogenetic distances were independent (r =–0.02, P =0.600, Figure S1).
Figure S1: Mantel's correlograms for the whole arboretum (A) and for each garden, separately (B). Filled and empty circles indicate significant and non significant correlations between Euclidean and phylogenetic distances, respectively. In (A), horizontal dashed line at r=0.9 represents the overall mantel's correlation at the arboretum scale.
To confirm that the overall pattern of host use by PPM was not biased by non random planting within the arboretum, we used a sensitivity test by running previous null models for each garden separately. Null models yielded qualitatively the same results as in the main analyses (Figure S2). This confirms that phylogenetic clustering of host range increased with PPM density, regardless of the relationship between Euclidean and phylogenetic distances.
Figure S2: Effects of PPM nest density on PPM host range for each garden separately. Results of null models are comparable with those shown in Figure 4 (main document).
References
Battisti, A. et al. 2015. Natural History of the Processionary Moths (Thaumetopoea spp.): New Insights in Relation to Climate Change. - In: Roques, A. (ed), Processionary Moths and Climate Change : An Update. Springer Netherlands, pp. 15–79.
Oksanen, J. et al. 2016. vegan: Community Ecology Package.
Table S1:Characteristics of pine species included in the present survey.
Species / No. trees / Origin / Plantation year(oldest, youngest) / Mean height
(m, mean ± SE) / Mean needle length (cm) / Mean needle width (mm)
Pinus aristata / 1 / North America / 1992 / 1.2 (-) / 3.5 / 0.9
Pinus arizonica / 1 / North America / 1998 / 2.0 (-) / 9.2 / 1.0
Pinus armandii / 7 / Asia / 1910 - 1964 / 20.1 (0.9) / 11.5 / 1.0
Pinus ayacahuite / 1 / North America / 1955 / 9.0 (-) / 7.8 / 0.8
Pinus banksiana / 4 / North America / 1941 - 1965 / 14.8 (3.3) / 3.5 / 1.25
Pinus bungeana / 7 / Asia / 1932 - 1940 / 14.1 (1.0) / 7.0 / 1.25
Pinus cembra / 4 / Europe / 1965 - 1984 / 2.0 (0.3) / 7.3 / 0.75
Pinus contorta / 11 / North America / 1923 - 1978 / 13.8 (1.7) / 5.0 / 1.3
Pinus coulteri / 2 / North America / 1984 - 1995 / 5.5 (0.5) / 23.0 / 2.0
Pinus densiflora / 4 / Asia / 1926 - 1957 / 7.8 (0.5) / 10.5 / 1.0
Pinus durangensis / 1 / North America / 1990 / 1.8 (-) / 16.0 / 0.8
Pinus engelmannii / 5 / North America / 1954 - 1955 / 18.1 (2.1) / 30.0 / 2.0
Pinus flexilis / 1 / North America / 1959 / 9.0 (-) / 5.5 / 1.25
Pinus glabra / 2 / North America / 1971 - 1971 / 3.0 (0.0) / 7.0 / 0.95
Pinus heldreichii / 2 / Europe / 1929 - 1945 / 9.5 (1.5) / 8.0 / 1.5
Pinus jeffreyi / 4 / North America / 1905 - 1960 / 18.2 (4.2) / 13.5 / 1.75
Pinus koraiensis / 3 / Asia / 1947 - 1983 / 7.3 (1.9) / 10.5 / 1.0
Pinus massoniana / 1 / Asia / 1940 / 15.0 (-) / 17.5 / 0.9
Pinus mugo / 6 / Europe / 1925 - 1990 / 3.3 (0.5) / 5.5 / 1.5
Pinus muricata / 2 / North America / 1929 - 1944 / 12.0 (6.0) / 11.0 / 1.5
Pinus nigra / 57 / Europe / 1884 - 1993 / 24.7 (0.8) / 12.0 / 1.7
Pinus palustris / 1 / North America / 1894 / 14.0 (-) / 32.5 / 1.5
Pinus parviflora / 3 / Asia / 1933 - 1965 / 10.0 (1.5) / 6.5 / 0.8
Pinus peuce / 4 / Europe / 1955 - 1965 / 14.8 (2.8) / 9.0 / 0.8
Pinus pinaster / 5 / Europe / 1949 - 1954 / 22.8 (1.1) / 16.0 / 2.0
Pinus pinea / 2 / Europe / 1958 - 1958 / 11.0 (2.0) / 13.5 / 1.25
Pinus ponderosa / 14 / North America / 1884 - 1960 / 25.2 (2.2) / 21.0 / 1.6
Pinus pumila / 1 / Asia / 1942 / 7.5 (-) / 5.0 / 1.0
Pinus resinosa / 2 / North America / 1957 - 1957 / 12.8 (6.2) / 15.0 / 1.0
Pinus rigida / 5 / North America / 1958 - 1960 / 12.0 (1.4) / 7.5 / 1.5
Pinus sabiniana / 1 / North America / 1931 / 27.0 (-) / 20.0 / 1.5
Pinus strobiformis / 5 / North America / 1955 - 1998 / 9.8 (3.6) / 7.0 / 0.8
Pinus strobus / 4 / North America / 1935 - 1954 / 19.2 (2.8) / 8.0 / 0.85
Pinus sylvestris / 4 / Europe / 1925 - 1945 / 16.5 (1.2) / 5.0 / 1.7
Pinus tabuliformis / 1 / Asia / 1983 / 3.5 (-) / 11.0 / 1.5
Pinus taeda / 4 / North America / 1954 - 1997 / 10.2 (4.3) / 17.0 / 1.2
Pinus taiwanensis / 2 / Asia / 1939 - 1939 / 10.0 (5.0) / 10.0 / 0.8
Pinus thunbergii / 4 / Asia / 1930 - 1984 / 10.0 (3.3) / 9.5 / 0.95
Pinus virginiana / 2 / North America / 1958 - 1958 / 13.5 (1.5) / 6.0 / 1.25
Pinus wallichiana / 1 / Asia / 1925 / 10.0 (-) / 14.5 / 0.8
Pinus washoensis / 1 / North America / 1994 / 3.5 (-) / 21.0 / 1.6
Table S2: Summary of GLS models. Coefficient values that significantly differ from zero are shown in bold font type.
Year / Pagel’s λ / Predictor / Model parameter estimate (b) / P-value2004 / 0.01 / Height / 0.047 / 0.049
Needle length / -0.037 / 0.132
Needle width / 0.018 / 0.468
2003 / -0.03 / Height / 0.143 / 0.028
Needle length / -0.061 / 0.345
Needle width / 0.122 / 0.074
2005 / -0.12 / Height / 0.133 / 0.080
Needle length / -0.132 / 0.062
Needle width / 0.173 / 0.014
2006 / 0.16 / Height / 0.309 / 0.007
Needle length / 0.004 / 0.972
Needle width / 0.117 / 0.348
1999 / -0.02 / Height / 0.109 / 0.402
Needle length / -0.015 / 0.912
Needle width / 0.288 / 0.042
2007 / -0.11 / Height / 0.344 / 0.055
Needle length / 0.469 / 0.007
Needle width / 0.151 / 0.370
2000 / 0.03 / Height / 0.288 / 0.119
Needle length / -0.029 / 0.880
Needle width / 0.462 / 0.025
2001 / -0.03 / Height / 0.312 / 0.163
Needle length / 0.003 / 0.989
Needle width / 0.661 / 0.007
2002 / -0.02 / Height / 0.572 / 0.159
Needle length / 0.279 / 0.498
Needle width / 1.113 / 0.013