Original paper
Plant chemistry and insect detoxification jointly shape invasion outcomes in competing leafminers
Gao, Kai; Yu, Hong-Wei; Zhao, Xin-Rui; Zou, Jing-Ning; Wang, Wen-Hao; Fang, Ting-Ting; Wu, Sheng-Yong; Xing, Zhen-Long; Lei, Zhong-Ren
published online: Feb 12, 2026
manuscript accepted: Jan 6, 2026
final revised version received: Oct 29, 2025
manuscript revision requested: Aug 20, 2025
manuscript received: Jul 21, 2025
Abstract
Species displacement is the most serious consequence of biological invasion, but whether exotic species can completely displace resident species remains debated. Varying displacement outcomes may occur during biological invasion. However, the underlying mechanisms have not yet been elucidated. Here, we investigated species displacement between two invasive leafmining flies (Liriomyza trifolii and Liriomyza sativae) on two prevalent host plants (cowpea, Vigna unguiculata, and luffa, Luffa aegyptiaca) through field surveys and controlled displacement experiments. We further examined host plant chemicals and insect detoxifying enzymes that may determine species displacement outcomes. The field survey indicated that L. trifolii dominated on cowpea plants but was not consistently dominant on luffa plants. In the species displacement experiments, L. trifolii consistently outcompeted L. sativae on cowpea plants in the field, greenhouse, and laboratory, whereas L. sativae typically outperformed L. trifolii on luffa plants. Metabolomic analyses indicated that the cowpea leaves were more nutritious, and the luffa leaves were more defensive. Further, the activities of detoxifying enzymes were higher in L. sativae than in L. trifolii, suggesting the advantage of L. sativae in utilizing the defensive luffa leaves. We found that contrasting displacement outcomes between closely related species may occur on different host plants, and these outcomes may be mediated by differences in plant quality and insect detoxifying capacity. Our findings highlight the host plant’s role in mediating various displacement outcomes and provide novel insights into the mechanisms underlying species exclusion or coexistence caused by biological invasion.
Keywords
biological invasion •
host plant quality •
insect pests •
Liriomyza sativae
•
Liriomyza trifolii
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Vigna unguiculata
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Luffa aegyptiaca
•
species displacement