Crops are subject to attack from a wide range of insect species in the wet tropical environment of Cambodia, resulting in extensive damage and economic losses. This illustrated field guide will assist with the identification of the major insect pests of the main upland crops in Cambodia - cowpea, maize, mung bean, peanut, sesame and soybean. However, not all insects found in the crops are pests; some insects and spiders play a significant role in keeping the insect pests under control. The guide provides a brief description of insect pests and the damage they cause, as well as information on a range of beneficial insects and spiders that can be found in upland crops in Cambodia. The impact of beneficial insects can be increased by integrated pest management and careful use of pesticides.