<i>N</i> -(3-methylbutyl)acetamide mediates male–male courtship in <i>Bactrocera dorsalis</i> through behavioral threshold modulation

Y Yuhua Zhang (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) Y Yaoyao Chen (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) W Wenlong Chen (State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences) S Shuyuan Xing (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) X Xirui Jin (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) Y Yuzhe Long (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) Z Zhihang Xu (Department of Applied Physics, Research Institute for Smart Energy) G Guohua Zhong (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University) X Xin Yi (Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University)

Abstract

Male–male courtship, observed across diverse taxa, is often regarded as an evolutionary paradox. Here, we address this paradox by demonstrating that such behavior in the globally invasive pest Bactrocera dorsalis arises as a byproduct of a context-dependent shift in the mating filter. We identify N -(3-methylbutyl)acetamide (MBA) as a critical signal that accumulates under high male density and female scarcity. At a threshold amount (~ 1,800 ng), MBA broadens the male’s mating filter, lowering the acceptance threshold for potential partners, thereby elevating courtship motivation and inducing hyperactivity. This broadened filter enables males to court suboptimal but potentially available females (e.g., mated or older individuals) that would otherwise be ignored, while also incidentally triggering male–male courtship. This behavioral shift is rapidly reversible upon encounter with virgin and young females, preserving an innate preference for these optimal partners. By identifying MBA as a chemical signal of mate unavailability, we reinterpret male–male courtship as a neutral byproduct of an adjustment of the mating filter under female scarcity, a trade-off between maximizing mating opportunities and accepting the incidental cost of misdirected courtship. This work bridges behavioral ecology with physiology, offering a mechanistic framework for how social environments dynamically reshape mate acceptance thresholds.

Article Details

Volume / Issue Vol. 123, Issue 29
Published July 21, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (9)

Y

Yuhua Zhang

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

Y

Yaoyao Chen

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

W

Wenlong Chen

State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences

S

Shuyuan Xing

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

X

Xirui Jin

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

Y

Yuzhe Long

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

Z

Zhihang Xu

Department of Applied Physics, Research Institute for Smart Energy

G

Guohua Zhong

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University

X

Xin Yi

Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, Department of Pesticide Science, College of Plant Protection, South China Agricultural University