Geographic distribution of terpenoid chemotypes in Tanacetum vulgare mediates tansy aphid occurrence but not abundance

Intraspecific variation of specialized metabolites in plants, such as terpenoids, are used to determine chemotypes. Tansy (Tanacetum vulgare L.) exhibits diverse terpenoid profiles that affect insect communities. However, it is not fully known whether patterns of their chemical composition and associated insects vary beyond the community scale. Here, we investigated the geographic distribution of mono- and sesquiterpenoid chemotypes in tansy leaves and their relationships with specific insect communities across Germany. We sampled tansy leaves from ten plants with and five plants without aphids in each of 26 sites along a north-south and west-east transect in Germany. Hexane-extracted metabolites from leaf tissues were analyzed by gas chromatography-mass spectrometry (GC-MS). Plant morphological traits, aphid occurrence and abundance, and occurrence of ants were recorded locally. The effect of plant chemotype, plant morphological parameters, and abiotic site parameters such as soil type..., This data was curated by collecting tansy (Tanacetum vulgare) plants from 26 sites along northwest-southeast transects in Germany. During the survey, GPS coordinates, abiotic site parameters, plants with and without aphids, ant species, and plant morphological data were recorded. Plants were then processed for chemical analysis with n-hexane extraction protocol and GC-MS analysis as described by Clancy et al., 2016. The plants were then clustered into chemotypes based on their mono- and sesquiterpenoid content by using \"hclust\" function in \"factoextra\" package in R. Different statistical analyses and tests were performed: The Discriminant Analysis of Principal Components (DAPC), generalized linear models, posthoc Tukey tests, and tanglegram of mono- and sesquiterpenoid chemotype trees. 
All the statistical analyses were conducted in R, using the \"hclust\", \"vegan\", \"adegenet\", \"chemodiv\", \"emmeans\" and \"car\" packages., , # Data from: Geographic distribution of terpenoid chemotypes in Tanacetum vulgare mediates tansy aphid occurrence but not abundance

[https://doi.org/10.5061/dryad.9p8cz8wqk](https://doi.org/10.5061/dryad.9p8cz8wqk)

## Description of the data and file structure

We collected the plant morphological and insect data (e.g. plant height, stems, aphid species (**Aphid occurrence**), counts (**Me.occ**), etc.) in 26 different sites from north to south Germany. We then used the plants for chemical analysis by using gas chromatography/mass spectrometry (GC-MS). The detected terpenoids were identified by using the National Institute of Standards and Technology (NIST), Mass Spectral Library (NIST 11). The quantification of the compounds was performed based on the dilutions of the external standards: sabinene, α-pinene, linalool, methylsalicylate, β-caryophyllene, α-humulene, geraniol, and bornyl acetate at different concentrations (pmol/g). We clustered the plants (**Sample ID**) into monoterpen...