Host plant phenotypic traits affect the structure of the associated consumer community and mediate species interactions. We compare herbivore assemblages from the canopy of the phenotypically variable tree Metrosideros polymorpha on Hawai‘i Island. Multiple distinct varieties of M. polymorpha frequently co‐occur, with variation in morphological traits. Using this system, we identify host and insect traits that underlie patterns of herbivore abundance and quantify the strength of host‐insect trait interactions.

The dataset includes host plant phenotypic traits (specific leaf area, leaf water content, foliar nutrients, trichome presence), as well as collection information. The dataset also contains the herbivorous insect community associated with this host plant, their abundances and life history traits. R code for analyses in this article is also included.

See Tielens & Gruner 2020 for full details. The data was collected from four focal sites on the west and southwest side of Hawai‘i Island where multiple varieties and phenotypes of Metrosideros polymorpha co‐occur. We sampled six M. polymorpha trees during two sampling events to ensure within‐site replication, allowing comparison across phenotypes with the same local environmental conditions.

Arthropods were collected from the outer canopy of the focal M. polymorpha tree. Each tree was sampled in 2014 and 2015, resulting in six replicates across four sites for two years. Canopies were accessed using the single‐rope technique. Samples were collected by quickly bagging multiple branches in the outer canopy, and using a pole pruner to clip branches (see assocciated article for further details). Samples were transported to the lab and specimens were extracted on the same day as collection. Specimens were extracted by gently shaking branches on an enclosed white surface and aspirating individuals that emerged. Foliage samples were carefully searched, but herbivores feeding completely enclosed within leaves or buds were not manually extracted. Specimens were kept in 95% ethanol before identification; we included only phytophagous species, and Hemiptera specimens were identified to (morpho) species, while Lepidoptera and Coleoptera were identified to family or morphospecies.

Leaf traits were measured on leaves sampled at the time of first insect collection, while insect traits were based on the literature (except for body size, which was also measured). See article and supplemental materials for more information on this.