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ARS Home » Southeast Area » Stoneville, Mississippi » Southern Insect Management Research » Research » Publications at this Location » Publication #434971
Research Project: Integrated Insect Control and Resistance Management Strategies for Row Crops in the Southern United States

Location: Southern Insect Management Research

Title: Early-Warning Assessment of Two-Spot Cotton Leafhopper (Amrasca biguttula) Using the Normalized Research Risk Metric (NRRM) Across Multiple Invasive Species

Author
item AHMED, MUHAMMAD - Clemson University
item George, Justin

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2026
Publication Date: 8/6/2026
Citation: Ahmed, M.Z., George, J. 2026. Early-Warning Assessment of Two-Spot Cotton Leafhopper (Amrasca biguttula) Using the Normalized Research Risk Metric (NRRM) Across Multiple Invasive Species. Insects. 17(816):1-14. https://doi.org/10.3390/insects17080816.
DOI: https://doi.org/10.3390/insects17080816

Interpretive Summary: The two spot cotton leafhopper (Amrasca biguttula) is a rapidly emerging invasive pest in the southeastern United States. Because it spreads quickly and triggers regulatory actions and economic loss concerns, growers and agencies need tools to identify high-risk invaders before they become widespread. We developed the Normalized Research Risk Metric (NRRM), a literature based early warning model that evaluates global research visibility. By applying NRRM to A. biguttula and several comparison species, we show that this pest exhibits strong early warning signals consistent with those of major invasive arthropods. NRRM can be used alongside ecological and eco climatic models to help predict which species are most likely to become future problems in agricultural and ornamental systems. This approach provides a practical, proactive supporting tool for anticipating invasive pests before they cause significant economic damage. This work aligns with the Secretary’s priorities and USDA mission areas by improving farm profitability, protecting crops from invasive pests, promoting soil health, and advancing sustainable pest management. Overall, this research provides practical guidance on managing pests, and helping farmers make informed decisions on selection of crop varieties, to build more resilient and sustainable agricultural systems.

Technical Abstract: The two spot cotton leafhopper (Amrasca biguttula) is an emerging invasive pest in the southeastern United States, with recent establishment in cotton, vegetables, and ornamental hibiscus. Its rapid spread, potential economic losses, and regulatory impacts highlight the need for additional early-warning tools capable of identifying high-risk arthropod invaders before widespread establishment. We developed and applied the Normalized Research Risk Metric (NRRM), a literature based framework that quantifies global research visibility using total publications, recent research, research momentum, and geographical breadth. A comprehensive multi database Web of Science search was conducted across all available indices using species specific synonyms, address filters, and harmonized country names. Six globally important invasive species were used to train the model, and A. biguttula was evaluated as the primary prediction species. The species exhibited high global research visibility (T = 403; C = 25) and a positive NRRM score (0.651), consistent with its long recognized pest status in Asia and its rapid emergence in the U.S. In contrast, Heliococcus summervillei received a strongly negative NRRM score (–1.14). NRRM provides a rigorous early warning indicator that can be integrated with ecological and eco climatic models to further improve the prediction of future invasive threats in agricultural and horticultural systems.