害虫经济阈值（Economic threshold，ET）作为农业害虫管理关键决策依据，是主要基于挽回作物损失的价值和防治费用的农业害虫防治经济阈值。在实践应用中，由于对害虫防治措施的生态代价考虑不足，往往导致阈值指标偏低，防治次数和农药使用量偏多。本文利用农药生态效应评估的最新研究进展，提出了充分考虑防治费用和防治生态代价的农业害虫防治生态经济阈值（Ecological and economic threshold，EET）概念，给出了基于农药生态风险指数的简便易行的数学模型和估算方法。生态经济阈值的提出与推广应用，不仅为现代农业害虫防治决策提供了科学依据，而且有助于我国的农药减量目标的实现。

Economic threshold (ET) was the key index for guiding agricultural pest management, which was based on the value of the saved crops and control cost in the pest management. Because the ecological cost of pesticide use often was less considered in the practical application, ET was lower and more pesticides were used. We proposed the concept of ecological and economic threshold (EET) with the aid of the new development in the assessment of ecological impacts of pesticide use, in which both the control cost and ecological cost of pesticide use were fully considered. The simple mathematic model and estimation method based on the  index of pesticide ecological risk use were presented. EET will be conducive to promote the pest management level and achieve purpose of pesticide reduction.