 This study estimates the economic benefit of natural enemies such as lady beetles in controlling pests in cotton fields in North China Plain, finding that an additional lady beetle provides an economic benefit of five cents, almost one cent, to farmers. The use of broad-spectrum insecticides by farmers is excessive and undermines their profitability and the natural pest suppression system. Doubling current lady beetle density in cotton fields could gain an estimated US$300 million for cotton farmers in China, providing a strong economic case for policies to move towards a more ecologically-based regime. Raising knowledge and awareness on the costs and value of biological pest control versus insecticides among farmers and policy makers and having effective extension service are priorities towards achieving a more ecologically-based approach to crop protection on smallholder farms. This article was authored by Jikun Huang, Ku Jiu, Wei Zhong, and others. We are article.tv. Links in the description below.