Feeding Preferences of Agrilus zanthoxylumi (Coleoptera: Buprestidae) in Relation to Host Plant Volatiles

TL;DR

This study explores how a beetle species prefers certain pepper plant varieties based on their leaf chemicals, which could help in creating eco-friendly pest control methods.

Contribution

The study identifies specific volatile compounds that drive the beetle's feeding preferences across Zanthoxylum varieties.

Findings

Agrilus zanthoxylumi adults prefer Z. bungeanum Fugu leaves over other varieties.

Key volatile compounds like (E)-4-hexen-1-ol and (−)-limonene are linked to feeding preferences.

Multivariate analysis revealed distinct volatile distributions among the three Z. bungeanum varieties.

Abstract

Understanding the feeding preferences of Agrilus zanthoxylumi Li Meng Lou, 1989 (Coleoptera: Buprestidae) adults across different Zanthoxylum bungeanum varieties and their underlying chemical drivers is important for developing sustainable pest management strategies. This study assessed adult feeding preferences on leaves of Z. bungeanum Fugu, Z. bungeanum Dahongpao, and Z. bungeanum Feng varieties and analyzed leaf volatiles to identify key differential compounds. We found that Z. bungeanum Fugu leaves were most preferred by adults. The volatile compositions differed markedly among the three varieties, with Z. bungeanum Fugu containing the most unique compounds. Factor analysis and partial least squares discriminant analysis (PLS-DA) further identified key differentiating compounds, including (E)-4-hexen-1-ol, (−)-limonene, (−)-α-pinene, γ-terpinene, α-terpineol, and linalyl acetate. The study suggested that host selection by A. zanthoxylumi may be driven by key volatiles that exhibit high concentrations and pronounced inter-varietal differences. These results provide a scientific basis for elucidating its chemical location mechanism and developing attractants, repellents, and environmentally friendly pest management strategies.

The Chinese pepper buprestid beetle, Agrilus zanthoxylumi Li Meng Lou, 1989 (Coleoptera: Buprestidae), is a major trunk-boring pest affecting the yield and quality of Zanthoxylum bungeanum. Clarifying its feeding preferences among different pepper varieties and their associations with host-derived volatiles is important for understanding and improving effective management strategies. This study conducted feeding tests under no-choice and dual-choice conditions to evaluate the beetle’s feeding preferences among three Z. bungeanum varieties—Fugu, Dahongpao, and Feng. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze leaf volatiles, with factor analysis and partial least squares discriminant analysis (PLS-DA) used to identify key volatiles. Results showed that A. zanthoxylumi exhibited the highest resting frequency and feeding amount on Z. bungeanum Fugu leaves, with the lowest on Z. bungeanum Dahongpao leaves. Significant differences in unique volatiles were observed among the three varieties. Z. bungeanum Fugu contained 17 unique components, including (E)-4-hexen-1-ol, (−)-limonene, and (−)-α-pinene, with significantly higher quantities than Z. bungeanum Dahongpao and bungeanum Feng. Multivariate analyses further revealed distinct distributions in volatiles, with γ-terpinene, α-terpineol, and linalyl acetate emerging as key compounds distinguishing varieties. These results indicate that the feeding preferences of A. zanthoxylumi are closely related to host volatiles, suggesting variety-specific compounds may serve as primary chemical cues driving its preferences.

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