Hormetic-like feeding alterations and intergenerational effects of afidopyropen in the cotton leafhopper Amrasca biguttula

Authors: TARIQ, KALEEM - Abdul Wali Khan University; SOHAIL, AMIR - Abdul Wali Khan University; Backus, Elaine; SAFI, MUHAMMAD - Abdul Wali Khan University; ULLAH, FARMAN - Zhejiang Academy Of Agricultural Sciences; HAQ, IHSAN - National Agricultural Research Center - Pakistan

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2025
Publication Date: 11/28/2025
Citation: Tariq, K., Sohail, A., Backus, E.A., Safi, M.S., Ullah, F., Haq, I.U. 2025. Hormetic-like feeding alterations and intergenerational effects of afidopyropen in the cotton leafhopper Amrasca biguttula. Pest Management Science. 82(3). https://doi.org/10.1002/ps.70364.
DOI: https://doi.org/10.1002/ps.70364

Interpretive Summary: Amrasca biguttula, commonly known as the cotton leafhopper, damages plants by injecting enzymatic saliva into their tissues and ingesting the resulting slurry, causing a condition in the plant called “hopperburn.” Afidopyropen, is a novel systemic insecticide used to control A. biguttula; however, how it kills the leafhopper is not yet fully understood. The mechanism of action of afidopyropen on A. biguttula was studied using electropenetrography (EPG), in which the plant and insect are connected into an electrical circuit resulting in waveforms that represent specific feeding behaviors. Six distinct waveforms were seen; among them were A2, which indicates active sucking/pumping with simultaneous secretion of enzymatic saliva, and A3, which indicates sucking without salivation. Results indicate that Afidopyropen functions primarily as an antifeedant, leading to starvation and death in A. biguttula, rather than exhibiting toxic effects to the nervous system. There was a strong relationship between dosage and feeding, leading to complete suppression of feeding at a concentration of 106.9 mg/L. This insight could improve the effectiveness and application of this new insecticide in managing leafhopper populations in the field.

Technical Abstract: Amrasca biguttula, commonly known as the cotton leafhopper, is a polyphagous pest found in Asia and Southeast Asia. It damages plants by injecting enzymatic saliva into their tissues and ingesting the resulting macerate. Afidopyropen, a novel systemic insecticide that is effective against sap-sucking pests, is suitable for managing A. biguttula; however, its mode of action is not yet fully understood. The mechanism of action of afidopyropen on A. biguttula was investigated via electropenetrography (EPG), which identified six distinct waveforms; among them are A2 and A3, which indicate active ingestion with and without simultaneous watery salivation, respectively. Afidopyropen functions primarily as an antifeedant, leading to starvation and death in A. biguttula, rather than exhibiting neurotoxic effects. Insects treated with afidopyropen died significantly slower than did insects subjected to starvation. EPG data revealed that afidopyropen significantly increased the duration of nonprobing events and strongly inhibited active ingestion, probably from general phloem cells, demonstrating a strong dose'dependent relationship leading to complete suppression at a concentration of 106.9 mg/L. Therefore, the inhibition of active ingestion, resulting in starvation, may be the primary mechanism of toxicity for afidopyropen. This study revealed that the toxicity of afidopyropen is due to starvation caused by the inhibition of active ingestion. This insight could improve the effectiveness and application of this new insecticide in managing leafhopper populations in the field.