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

Authors: Follett, Peter; HOLLINGSWORTH, ROBERT - Former ARS Employee; Wall, Marisa; CALVERT, FRANCES - Former ARS Employee

Submitted to: Journal of Asia-Pacific Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2019
Publication Date: 6/1/2019
Citation: Follett, P.A., Hollingsworth, R., Wall, M.M., Calvert, F. 2019. Survey of flowering plants in Hawaii as potential banker plants of Anthocorid predators for thrips control. Journal of Asia-Pacific Entomology. 22(3):638-644. https://doi.org/10.1016/j.aspen.2019.05.001.
DOI: https://doi.org/10.1016/j.aspen.2019.05.001

Interpretive Summary: A survey was conducted of flowering plants along roadsides on the Big Island of Hawaii to identify thrips and anthocorid predators of thrips. If a plant could be found that harbored thrips and high numbers of anthocorid predators, this plant might have potential as a 'banker' plant. A banker plant is a species of plant, different from the crop, which supplies natural enemies for control of crop pests. Banker plants supply predators, which feed and multiply on arthropods that occur on them before dispersing to crop plants to find additional prey. Banker plants provide growers with an option for biological control of pests in greenhouses and can increase the probability that beneficial insects will become established on the commercial crop. They are an economical method of providing a reproducing population of natural enemies and may also reduce reliance on pesticides and thus reduce the risk of insect resistance to applied chemical controls 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 (including thrips) found in association with M. tanarius are known pests. Macaranga tanarius has potential as a banker plant to help suppress thrips populations in greenhouse crops with anthocorid predators.

Technical 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, indicating the plant species was a breeding host for thrips. Five different species of anthocorids – Orius persequens (White), Orius tristicolor (White), Paratriphleps laeviusculus Champion, Montandoniola confusa Streito & Matocq and Blaptostethus pallescens Poppius – were collected on 22 different plant species in 10 plant families. The plants with the highest numbers of anthocorid adults and nymphs present were Macaraga tanarius (L.) Müll. Arg (Blush Macaraga), Verbesina encelioides (Cav.) Benth & Hook. Ex A Gray (Golden Crownbeard), Tithonia diversifolia (Hemsl) (Tree Marigold), Acalypha hispida Burm. f. (Chenille bush), and Coreopsis lanceolata L. (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.