The use of wireless communication is a major trend in the so called Supervisory Control and Data Acquisition systems (SCADA). Consequently, Wireless Industrial Sensor Networks (WISN) were developed to meet real time and security requirements needed by SCADA systems. In term of security, WISN suffer from the same threats that those targeting classical WSN. Indeed, attackers mainly use wireless communication as a medium to launch these attacks. But as these networks are used to manage critical systems, consequences of such attacks can be more harmful. Therefore, additionally to the use of cryptographic and authentication mechanisms, Intrusion Detection Systems (IDS) are also used as a second line of defense. In this paper we propose an efficient IDS deployment scheme specially tailored to fit WISN characteristics. It builds a virtual wireless backbone that adds security purposes to the WISN. We also show that the proposed deployment scheme provides a good traffic monitoring capability with an acceptable number of monitoring nodes. It particularly allows detecting that a packet has been forged, deleted, modified or delayed during its transmission.