A systems approach to mitigate pest risk for market access of cut flowers exported from Hawaii

Authors: KIM, KYEONGNAM - Orise Fellow; Zarders, Dominique; TANOUYE, ERIC - Green Point Nurseries; HARA, ARNOLD - University Of Hawaii; Cha, Dong

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2025
Publication Date: 1/3/2026
Citation: Kim, K., Zarders, D.R., Tanouye, E., Hara, A., Cha, D.H. 2026. A systems approach to mitigate pest risk for market access of cut flowers exported from Hawaii. Journal of Economic Entomology. 1-9. https://doi.org/10.1093/jee/toaf284.
DOI: https://doi.org/10.1093/jee/toaf284

Interpretive Summary: Hawaii’s flower industry is important to the local economy, but many shipments are rejected due to insect pests. To help growers meet export standards and reduce pest-related shipment rejections, this study tested the effect of a systems approach on pest infestation levels in cut flower exports. For ginger and heliconia cut flowers, combination of insecticide spraying as pre-harvest treatments and washing and hot water treatments as postharvest treatments could significantly reduce flower infestation by aphids, ants, scale insects, and mealybugs, which resulted in completely pest-free ginger and heliconia flowers before shipping. The proposed systems approach offers a practical way for Hawaii growers to maintain access to U.S. mainland and international markets by producing clean, export-ready flowers.

Technical Abstract: The floriculture and nursery industry is a key contributor to Hawaii's economy, with ornamental crop exports, particularly cut flowers, accounting for a significant portion of sales. However, pest-related shipment rejections have increasingly threatened market access. As a first step to develop an effective systems approach for maintaining market access, we analyzed California interception records from 2012-2016, which revealed 582 cut flower shipment interceptions from 92 Hawaiian growers and shippers, with rejections primarily due to ants, aphids, mealybugs and scale insects for non-orchid cut flowers (e.g., ginger and heliconia) and thrips for cut orchid flowers (e.g., Dendrobium). For targeted trials of ginger and heliconia, the effect of sequential pre-harvest (systemic insecticide spraying and ant baiting) and postharvest treatments (washing, hot water treatment, and second washing) were evaluated under commercial conditions. While individual treatments alone did not achieve complete disinfestation of ginger and heliconia, combining them as a systems approach led to zero detectable infestation across eight harvests during the second year of the study, indicating this may be a feasible phytosanitary strategy for Hawaii-grown cut flowers. In contrast, for Dendrobium orchids with limited postharvest treatment options, pre-harvest insecticide programs were ineffective for managing thrips, with 30% of Dendrobium flowers and 70% of the flower sprays remaining infested post-insecticide treatment, highlighting the need for improved thrips management and the potential for integrating with postharvest fumigation. Overall, our results demonstrate the potential of systems approach in reducing pest interceptions and supporting continued access of Hawaii-grown cut flowers to U.S. mainland and international markets.