We tested the hypothesis that feeding by a specialized insect is more closely associated with the chemical similarity of potential host plant species than it is to phylogenetic similarity of these species. Tests were conducted with Brassicaceae-specialized weevil, Ceutorhynchus cardariae Korotyaev (Coleoptera: Curculionidae), on 13 test plant species differing in their suitability as hosts for the weevil. We compared the associations between feeding by C. cardariae and either phenotypic similarity (secondary chemistry – glucosinolate profile) or genetic similarity (sequence of the chloroplast gene ndhF) using two methods – simple correlations or strengths of association between feeding by each species, and dendrograms based on either glucosinolates or ndhF sequence (i.e., a phylogram). For comparison with C. cardariae, we performed a similar test with the oligophagous Plutella xylostella (L.) (Lepidoptera: Plutellidae) using the same plant species. The data sets are the feeding data from bioassays with both species, the glucosinolate profiles of the test species, and a matrix of similarity in glucosinolate profiles among the test plant species.

There are four files:

Rapo_et al_Glucosinolates _RawData.csv
Columns: Plant Species, Population ID, Ind# (plant), Y/O (young/old leaf), Label (internal code), subset (internal code), Glc Weight (weight of tissue extracted), Names of glucosinolates (columns J-AJ) with values in µmol, Total = sum of columns J-AJ

Rapo_et al_Glucosinolate Distances_young leaves.csv
Distance matrix based on similarity of mean glucosinolate profiles for all species used to calculate dendrogram. Methods as in Rapo et al.

Rapo_et al_Glucosinolate Distances_old leaves.csv
Distance matrix based on similarity of mean glucosinolate profiles for all species used to calculate dendrogram (old leaves only). Methods as in Rapo et al.

Rapo_et al_Glucosinolate Distances_all leaves.csv
Distance matrix based on similarity of mean glucosinolate profiles for all species used to calculate dendrogram(young leaves only). Methods as in Rapo et al.