Equivalent predatory relationships in natural enemy communities and their potential to control aphids in wheat fields

Author of the article:Wumuti·Abahe1, 2** LIANG Xiao-Yi1 ZHANG Xing-Rui1 LI Zhou1 QI Le1 GE Feng1***

Author's Workplace：1. Shandong Key Laboratory for Green Prevention and Control of Agricultural Pests, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China; 2. The Tenth Division Agricultural Science Research Institute of the Xinjiang Production and Construction Corps, Beitun 836000, China

Key Words： predatory equivalent relationship; predatory natural enemies; wheat aphids; Cnidium monnieri; biological control

Abstract：

 [Aim]  In response to the coexistence of multiple natural enemies and various insect stages in the field, a quantitative analysis of the predation equivalence among natural enemies is conducted to clarify their control efficacy against pests. This study aims to lay the foundation for developing ecological pest management strategies and technologies. [Methods]  By reviewing literature on the functional responses of natural enemies in predation, data on the daily predation rates of common predatory natural enemies on aphids were collected to construct a predation equivalent relationship and determine the predation equivalent coefficient. Combined with field survey data of natural enemies and wheat aphids on wheat and the functional plant Cnidium monnieri, the theoretical values of multiple natural enemies co-predating on wheat aphids were calculated based on the equivalent relationship. These theoretical values were then compared with the actual occurrence of wheat aphids to assess the control efficacy of the natural enemy community in wheat fields against wheat aphids. [Results]  The predation equivalent equation effectively integrates the predatory capacity of multiple natural enemy species and their various developmental stages in the field, establishing a unified quantitative model. This provides a practical tool for evaluating the predation effect of natural enemy communities on wheat fields. Based on this, the pest control efficiency of natural enemies in wheat fields of eastern Shandong was analyzed. A simulation of functional plant C. monnieri intercropped with wheat at a 1︰30 ratio demonstrated that when C. monnieri sustains a natural enemy density of 15 individuals/ m², the natural enemy communities in the wheat field can consume up to 57 684 wheat aphids per 667 m² (calculated as 22 m² of C. monnieri per 667 m² wheat field). When the actual aphid population falls below this threshold,

natural enemies can effectively suppress wheat aphid damage. [Conclusion]  The predation equivalent equation= QUOTE  

serves as a robust tool for quantifying the aphid-predation capacity of field natural enemy communities, aiding in the assessment of their practical pest control potential. This approach will provide decision-making support for utilizing natural enemies in wheat fields and advancing ecological aphid management strategies.