Insect species richness for each plant species and insect-plant interactions from the Database of Insects and their Food Plants [DBIF]

For a full description of all processes involved in data collection/generation see the supporting documentationsupplied with this data. In summary, the following processes were applied to the full DBIF dataset in order to generate this dataset: - Only data on ‘higher’ plants (seed plants and ferns) were included, using only insect-plant records that were expertly verified as reliable and included in previous large-scale analyses (Ward 1988; Ward & Spalding 1993; Ward et al. 1995; Ward et al. 2003) - Only records that were certain to have occurred in Great Britain were included, and any records originating from captive breeding studies were excluded - All records not at a species level were removed, and all sub-species/cultivar/variety information were ‘upgraded’ to the species level - Several sources were used to group together plant and insect species listed under different synonyms - Native status and introduction dates (for neophytes) were assigned to plants from several data sources, with plants classified as neophyte (non-native, arrived post-1500), archaeophyte (non-native, arrived pre-1500), or native (primarily Holocene colonists) - Distribution size was quantified as the number of hectads (10 x 10 km grid squares) that a plant was recorded in between 1987-1999 (within Great Britain including the Isle of Man – vice counties 1-112) - Phylogenetic relationships between plants were trimmed from a recently published global phylogeny of vascular plants, producing a custom phylogeny - Four phylogenetic isolation measures were calculated - Insect community distinctiveness was defined as the Chao-Sorensen abundance-based dissimilarity between the insect community on a given non-native host, and the insect pool found on native plants within the DBIF - Only plants that hosted an insect richness ≥ 10 were included, ensuring that host plants had been sufficiently sampled for dissimilarity calculations - All DBIF data sources were trimmed down to the article level by removing page number information