This article shows the implementation of a wireless image-sensor node capable of taking images of plagues that attack fruits crops. Images can be transmitted over a wireless sensor network in order to build the plague population database and to take appropriate countermeasures in case of infection. Wireless sensor networks are suitable to implement such application, however the technology is certainly conditioned by economic constraints and the tendency is to use low-cost commercial nodes with constrained hardware resources. When trying to build an application that involves acquisition, processing and transmission of images, it is often argued that commercial available nodes can not fulfill the application specifications. Reported approaches to tackle the problem are to design ad-hoc high-performance nodes by using enhanced hardware resources, clearly superior to those of commercial nodes. It increases the cost against the WSN philosophy (i.e. low-cost nodes and constrained hardware resources usage). Contrary to the established, this article shows the achieved design of a low-cost wireless image-sensor nodes that incorporate image handling capabilities with constrained hardware resources. The implemented node and the WSN have achieved all the application requirements. Results and conclusions are offered.