Survey of flowering plants in Hawaii as potential banker plants of anthocorid predators for thrips control

Abstract

Abstract Flowering plants in gardens and along roadsides on the Big Island of Hawaii were sampled for thrips and anthocorid predators of thrips. A total of 171 plant samples, comprising 859 plant sample units (e.g. flowers or flower clusters) were collected from 56 species of plants in 25 families. Adult thrips were found on 43 plant species, and 32 of these also had larval thrips of the same species, indicating the plant species was a breeding host for thrips. Five different species of anthocorids – Orius persequens, Orius tristicolor, Paratriphleps laeviusculus, Montandoniola confusa, and Blaptostethus pallescens – were collected on 22 different plant species in 10 plant families. The plants with the highest numbers of anthocorid adults and nymphs present were Macaranga tanarius (Blush Macaraga), Verbesina encelioides (Golden Crownbeard), Tithonia diversifolia (Tree Marigold), Acalypha hispida (Chenille bush), and Coreopsis lanceolata (Lance-leaf Coreopsis). Macaranga tanarius was found to be the best host plant for anthocorids, with an average of 25.5 adult and 21.1 larval anthocorids per plant sample. Orius persequens was the most abundant anthocorid on M. tanarius with average adult and larval densities of 24.1 and 17.3 per plant sample, respectively. None of the insects found in association with M. tanarius are known pests. Macaranga tanarius has great potential as a banker plant to help suppress thrips populations in greenhouse crops with anthocorid predators.