Novel insecticide mode-of-action for managing Rice Delphacid, an invasive US rice pest
Texas A&M researchers are evaluating new mode-of-action insecticides, including Flonicamid and Dinotefuran, to control Rice Delphacid, an invasive piercing-sucking pest in US rice production. Field trials in Texas demonstrate Flonicamid significantly reduces pest density, addressing a critical gap since no insecticides are currently labeled for this species.
Overview
Rice Delphacid (Tagosodes orizicolus) is an emerging invasive pest threatening rice production across the southeastern US rice belt. Beyond direct feeding damage, this piercing-sucking insect transmits Rice Hoja Blanca Virus (RHBV), compounding its economic impact. No insecticides are currently labeled for Rice Delphacid control, leaving growers without effective management tools. Texas A&M University researchers are evaluating novel mode-of-action chemistries, particularly Flonicamid (a pyridine carboxamide) and Dinotefuran, which act as feeding deterrents against hemipteran pests. Initial field efficacy trials in heavily infested Texas rice fields demonstrated that Flonicamid significantly reduced Rice Delphacid density compared to untreated plots at both 6 and 10 days after application.
Technical specifications
Target pest: Rice Delphacid (Tagosodes orizicolus), a hemipteran insect that feeds by piercing and sucking plant tissues and vectors Rice Hoja Blanca Virus.
Candidate chemistries under evaluation:
- Flonicamid — a pyridine carboxamide compound with selective activity against hemipteran pests, functioning as a feeding deterrent
- Dinotefuran — a neonicotinoid-class chemistry with novel mode of action against sucking insects
- Comparative standards — Acephate and Lambda-cyhalothrin included as benchmark treatments
Validation approach:
- Randomized complete block design field trials with four replications per treatment
- Sampling at 6 and 10 days after insecticide application to assess population reduction
- Planned greenhouse cage studies evaluating nymph and adult mortality, sublethal effects on next generation, and efficacy across three rice growth stages
- Multi-location field assessments tracking RD population, hopperburn damage, RHBV screening at tillering and heading stages, and grain yield at harvest
Key finding from initial Texas field trial: Flonicamid-treated plots outperformed the untreated check in reducing Rice Delphacid density at both sampling dates (P < 0.05).
Technology readiness level
This research is currently at field validation stage (TRL 5–6). A field efficacy trial has been completed in Texas with statistically significant results for Flonicamid. Planned 2023 greenhouse assays will evaluate mortality, sublethal effects, and efficacy across multiple rice growth stages. Follow-up 2023 field trials at two locations will assess population dynamics, virus transmission, and yield impacts, with a potential expanded three-location trial in 2024. The goal is to generate the efficacy data package needed to support insecticide labeling for Rice Delphacid management in US rice production.
About Texas A&M University, College Station
Texas A&M University in College Station is a comprehensive public research university and the flagship of The Texas A&M University System, combining broad academic strengths with a strong applied‑research culture. Industry collaborates on the Texas A&M‑RELLIS campus—an integrated education, research and testing environment that supports large‑scale experimentation and proving grounds—and through the Texas A&M Transportation Institute’s facilities in Bryan‑College Station. A statewide extension network connects university expertise to companies and communities across all Texas counties, enabling rapid piloting and deployment. Research is supported by competitive federal funding from agencies such as NSF, NIH, DOE, USDA and DoD, alongside state and industry sponsorship. Texas A&M Innovation provides IP management, licensing and commercialization pathways across the system.
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