Management of pests is an important task in agriculture. Integrated Pest Management (IPM) is a way to prevent pest risks for long term using effective methods. Use of IoT for integrated pest management is unavoidable as it involves various tools from biological, chemical, mechanical and cultural field. Information about pests and all these tools needs to be maintained. Storing this information as ontology is the best option, as it then can be used by number of automated systems in agricultural field. Information in terms of ontology can be used by web services and can be made available online. It will help not only researchers in agriculture field but also farmers to manage pests and improve yield percentage. We describe automated method for construction of IPM ontology as web ontology language document and explain how it can be made available to farmers as an IoT application.